Greetings all,

I took my RX8 into the dealer yesterday to have my CD player replaced since it began skipping seriously upon minor bumps. While there I told them the history of my lousy gas mileage (last two tanks around 11MPG, overall average 15 MPG over 183 gallons, 2762 miles). So, they ran some tests and found code P0128. According to the tech this indicated that the car thought it was in a perpetual cold state, and stayed completely rich all the time! He reset the code and reflashed the PCM to the latest update. While they were at it they put it a new set of higher temperature plugs. I am hopeful that this will help my consumption. I filled up the tank to give it a go, and will report back after this tank.

Look forward to the update...

me too.. i wonder if i have this problem too

That makes sense.

The trouble code P0128 is the "Coolant Thermostat (Coolant Temp Below Thermostat Regulating Temperature)" code. Apparently it was a "pending" troublecode, otherwise the check engine light - CEL (a.k.a. Malfunction Indicator Light - MIL) would have come on too.

Looking forward to your future posts regarding gas mileage!

yes, this is extremely interesting... i'll sticky it if your findings are significant :)

Did they test or replace the temperature sensor and associated wiring?

Here's a service bulletin about the "P0128" error code. The procedure is to reprogram the PCM as you indicated. Unfortunately, the bulletin is rather cryptic in describing what the problem is and more importantly what it suppossedly fixes after the reprogram is done.

http://www.finishlineperformance.com/rx8/docs/01-024-03.html

Originally posted by VelocityRedRX8

So, they ran some tests and found code P0128. According to the tech this indicated that the car thought it was in a perpetual cold state, and stayed completely rich all the time!

Hi VelocityRedRX8,

Thanks for the info.

Do you notice any difference in the way the car idles or accelerates now?

When the car was running rich all the time, did it idle higher then it does now after the engine has warmed up?

I'd be interested in hearing all the changes you notice since the fix. I hope you get better gas mileage now :) .

regards,
rx8cited

Amazing what a technician can do if he actually believes you and looks for the problem. The only thing anyone else has gotten is "EPA numbers are estimates only under extremely controlled conditions." Nice to him to actually investigate and find something!

Interesting note on the bulletin: It says after the reprogramming, a road test is necessary so the ECU can relearn. THe problem is, it is relearning according to the garage mechanics driving habits, not the owners; who knows how that knucklehead will drive. Has anyone ever talked a dealership into letting the owner conduct the road test, with a technician in the right seat?

The 'learning' only works over the last 15miles or so anyhow, it wont take long to relearn to your style.

Very intrested in this possible fix, not usre it'll explain everyone spoor gas milage , but it might.

Originally posted by RobDickinson
The 'learning' only works over the last 15miles or so anyhow, it wont take long to relearn to your style.

I'm not quite sure what this means. Are you saying every 15 miles the ECU "relearns" your style? That's a pretty short-term memory and I'm not sure how useful it would be. I would have thought it would remember my driving style over some period of time and adjust engine settings accordingly. If it's only a 15-minute memory this would be of limited use.

Originally posted by Maniac
DTC P0128 is a coolant thermostat problem.
DTC P0456 is an EVAP system leak.

Neither of these are likely to manifest themselves as performance issues and are likely due to minor variations in manufacturing tolerances in the sensors.
This TSB is to install a new PCM code to mask this issue, not really a fix, per se.

DTC - Diagnostic Test Code
WDS - Worldwide Diagnostic System
ESI - Electronic Service Information (Mazda's Online Service)
PCM - Powertrain Control Module

The above is quoted by maniac, as to the P0128 error code. Taken from:
http://www.rx8club.com/showthread.php?s=&threadid=14188

But hope is not dashed, as they arent likely to cause any performance issue, but that doesnt mean they arent :D

Well, not my hops at least sinc eI have no issues there anyways :D

Well, ive started hot, started cold, drove in city, and on Highways, (last trip was little Rock to Atlanta VPC) and gas miliage seems totally random. I was getting 18.8mpg on Highway @90mph and She can drink a quarter of a tank in 20 miles if i lean on her.

I already had the dealer flash my ecu for cel problem.
My cel never came on after that.

My dealer shouldn't give me any problem if I want this done too right?

Originally posted by 8_wannabe
I'm not quite sure what this means. Are you saying every 15 miles the ECU "relearns" your style? That's a pretty short-term memory and I'm not sure how useful it would be. I would have thought it would remember my driving style over some period of time and adjust engine settings accordingly. If it's only a 15-minute memory this would be of limited use.

LEARNING COMPUTER (http://home.covad.net/~store006/Learning_Computer.wav)

LOL, I was looking for that wav yesterday but couldn't find it.

i too am anxiously awaiting hearing back as to whether or not there was improvement with MPG. my car is about 6 weeks old. i'm averaging around 13-15 MPG (city/freeway). i knew i wasn't buying a super fuel effiecient car ... but 13-15 is a far cry from 18-24. i have reported my concerns to the dealership mechanic. he claims that the poor fuel economy is to be expected in the RX models. i think the issue deserves more attention than that.

also ... just wondering if you find this strange. today i picked up my spacepug from the mechanic (oil light sensor issue fixed with new oil pan). check it out. they brought my car around and shut the engine off cold. given that this is a mazda dealership, should we be able to trust that they know how to care for the rotary engine? should i complain or let it go?

thanks for all your help. your postings are very informative!

cheers,
balletsushigirl

Originally posted by balletsushigirl
... just wondering if you find this strange. today i picked up my spacepug from the mechanic (oil light sensor issue fixed with new oil pan). check it out. they brought my car around and shut the engine off cold. given that this is a mazda dealership, should we be able to trust that they know how to care for the rotary engine? should i complain or let it go?

cheers,
balletsushigirl New car, new rotary which hasn't been around for 10 years of so. I'm not surprised dealership mechanics or shop helpers, etc are unaware of the issue. If you are concerned you should let the receiving tech know the start/stop procedure to avoid a possible flood. From what I've read since I've never flooded mine, is that the occurrence seems to happen on a cold engine that was then shutdown right away. If the engine is warm from riding around I don't think it’s much of an issue.

when my car was brought around after service yesterday it was complely warmed up. yours should have been too.

it absolutely WAS NOT warmed up. the guy started it up, moved it like 20 feet, shut off the engine. i was pissed off. more so, because when i dropped it off, i asked specifically that this NOT be done.

-BSG

Originally posted by Nubo
Did they test or replace the temperature sensor and associated wiring?

To my knowledge there was no replacement, only a clearing of the code end PCM re-flash

Originally posted by rx8cited
Hi VelocityRedRX8,

Thanks for the info.

Do you notice any difference in the way the car idles or accelerates now?

When the car was running rich all the time, did it idle higher then it does now after the engine has warmed up?

I'd be interested in hearing all the changes you notice since the fix. I hope you get better gas mileage now :) .

regards,
rx8cited

Hi rx8cited,

The difference I have noticed is that the car DOES seem stronger at > 6000 RPM. However, initial back-of-the-envelope calculations suggest no more than 15mpg. But - I will fill up the tank tonight in preparation for a 475 mile round trip to Cleveland tomorrow. Stay tuned. I'll post the MPG figures upon my return.

Originally posted by balletsushigirl
it absolutely WAS NOT warmed up. the guy started it up, moved it like 20 feet, shut off the engine. i was pissed off. more so, because when i dropped it off, i asked specifically that this NOT be done.

I think you have a right to be pissed. We should expect Mazda mechanics know this problem better than anyone. I realize there is a learning curve, but if we all make a point of it when visiting dealerships, pretty soon each joe ragman will understand. The alternative is the occasional flooded engine, and we all know now what a huge pain in the butt that can be.

By raising a stink now, we can avoid problems for some poor owner in the future. "The engine you save might be your own."

btw, great comment sushigirl. I posted it in this thread (http://www.rx8club.com/showthread.php?s=&postid=186102#post186102) where it is more relevant.

Originally posted by 8_wannabe
btw, great comment sushigirl. I posted it in this thread (http://www.rx8club.com/showthread.php?s=&postid=186102#post186102) where it is more relevant.

thank you "8_wannabe"

i'm new to this whole thing -- i've never read or posted messages to any forum before (just joined today) and never had a car worth caring about either!

i'm thankful for everybody's participation. it helps people like me to become informed (and avoid looking like a typical, ignorant girls who don't know anything about their cars)!!! knowledge IS power!

-BSG
:D :D

Originally posted by balletsushigirl
i'm thankful for everybody's participation. it helps people like me to become informed (and avoid looking like a typical, ignorant girls who don't know anything about their cars)!!! knowledge IS power!


No prob. Every girl here is powerful; just ask Elara! Welcome to the forum and congrats on the new car.

Originally posted by balletsushigirl
it absolutely WAS NOT warmed up. the guy started it up, moved it like 20 feet, shut off the engine. i was pissed off. more so, because when i dropped it off, i asked specifically that this NOT be done.

-BSG

You know, the lead tech made the comment that he couldn't start mine in the morning, when they were going to install the CD player. So, he said he'd check the plugs. THEN he said, "Well, I had these new high-temperature plugs in after having back-ordered them so I put them in for you."

My guess is that they cold-started the car to move it around the service area and then parked it, then shut it down. So it ended up flooded. Got new plugs though! :)

Originally posted by VelocityRedRX8
My guess is that they cold-started the car to move it around the service area and then parked it, then shut it down. So it ended up flooded. Got new plugs though! :)

Definitely. He was just giving you a line about just putting in plugs for you as he was too embarassed to admit the truth.

hey! Im new to this forum just send in today, I notice that the gas mileage on my RX8 from 1 to 800 miles is 11 mpg city/hiway driving. I alway keep my rpm around 5500 to 6000 before I shift gears. I was shifting at 3000 to 4500 rpms. but no change in the 11 to 12.5 mpg. I love this car .maybe it's my driving any Ideas:)

quote:
--------------------------------------------------------------------------------
Originally posted by balletsushigirl
i'm thankful for everybody's participation. it helps people like me to become informed (and avoid looking like a typical, ignorant girls who don't know anything about their cars)!!! knowledge IS power!

--------------------------------------------------------------------------------

BSG -

I agree. Knowledge IS power! I can't get over how many times I've already repeated things learned in this forum when dealing with the RX-8 salespeople and mechanics.

I see you teach math and based on what you've stated in your other posts I really, really doubt the Mazda mechanics are thinking "ignorant girl" when YOU walk away.

My wife is the same way. Her father was a "BIG wheel" in the automotive industry. He didn't have any sons, so his four daughters learned to fix stuck chokes, replace water pumps and drive ANYTHING with an engine. As a teenager (before computers) she worked in the billing department of a large chevy dealership and knew hundreds of billing code numbers by heart. For our first ten years of marriage she would go to the service managers and dispute line by line almost every repair bill we ever received stating things like "I see by this code number you’re trying to charge us for an entire box of rags". I can remember at least two really big repair bills that she had cut almost in half by the time she was done with them. Man, talk about a perfect woman! :D :) :p :cool:

I unplugged my battery for 12hours to reset the ecu. After I did that I filled up my gas tank and with just a the first quarter of a tank I hit 76 miles so far I have 130 and have about half a inch till half tank mark. Of how it’s heading now I think I might be able to get high 200 maybe low 300s. I will tell u how much my gas tank last after I need to fill up. That would be funny if my gas issue was fixed by resetting the ecu.

I average 250-280 per tank. combo highway and city.

I have a pretty good CD skip problem as well. It is interesting to know that they will replace the player. I also think I have the hesitation problem, and I think I switched of the DSC and have not noticed the problem again, but to be honest I didn't relate the two n(hesitation and DSC). Will have to experiment some more, but it just snowed like hell here so driving will be curtailed for a while (don't want baby in the snow, no siree).

Since I bought the car I've averaged 190.79 miles per tank. The worst being 158.1 and best being 227.0

just joking damm that is really good my average is 220-245 the most.I only got 245 on all highway comming from Nj-fL

If you really want to see if it's improved, PLEASE calculate miles per gallon. Miles per tank is so inaccurate as to be almost useless - a "tank" is not a unit of measure by any means.

Regards,
Gordon

Originally posted by balletsushigirl
it absolutely WAS NOT warmed up.

My car stays warm for hours after its driven for a while. I'm all for giving shop guys hell when they deserve it, but unless you got in and noticed the temp gauge, I'd let it go.

Originally posted by MEGAREDS
My car stays warm for hours after its driven for a while. I'm all for giving shop guys hell when they deserve it, but unless you got in and noticed the temp gauge, I'd let it go.

i started the car and the gauge was on cold. the attendant didn't even run it for more than 60 seconds. a pamphlet "rx-8's for dummies" would be nice to distribute to those we must entrust our vehicles. perhaps i'll drop a note in the suggestion box.

-BSG

Originally posted by balletsushigirl
i started the car and the gauge was on cold. the attendant didn't even run it for more than 60 seconds. a pamphlet "rx-8's for dummies" would be nice to distribute to those we must entrust our vehicles. perhaps i'll drop a note in the suggestion box.

-BSG

Yeah, its frustrating when you know more than the service techs :(

Perhaps a steering wheel cover with a warning to check the guage before shutting the engine off? Hmmm... I can see the auction now on Ebay.

Greetings all.

I've put about 550 miles on the car since the 'fix' and here are the results. MPG post fix, prior to extended highway trip: a whopping 11.96 MPG! :( MPG on Cincinnati -> Cleveland round trip (about 472 miles): 18.2MPG. This was done at pretty high average speed.

So, to summarize - my 'normal' non-highway MPG has not changed. it's still around 12. I'll run another tank to confirm, and inform the dealer. Any advice would be appreciated.

One final note - I have installed the RotaryExtreme CAI. My dealer warns me that it could have a negative effect on MPG due to changing the turbulence the engine is expecting. (??).

Back to the drawing board...

Interesting VelocityRedRX8, My MPG is pretty low now too, about 12 MPG! used to be 18-20. Lately it's been really cold out, and about halfway to work my car finally warms up. My car runs rich as hell too. Instead of a fuel tank, I think I need a fuel tanker. I'm going to stop by the dealer this week.

Dang, that's low MPG compared to my Twin Turbo RX7 that makes 280 hp (lightly modded). It's one good reason to stay away from RX8. (the other being poor dealer service/knowledge on rotary).

Originally posted by djantlive
Dang, that's low MPG compared to my Twin Turbo RX7 that makes 280 hp (lightly modded). It's one good reason to stay away from RX8. (the other being poor dealer service/knowledge on rotary).

first of all, I don't think you own an RX8, so your posts are very subjective, and not quatified personally. Second of all, I get about 11 mpg, but I floor it all the time, so I deserve it! Other gassers, I would get about 15 mpg on other turbo cars, so the RX8 is not that far off.

What dealers are you quoting as having poor service/knowledge on rotaries? I doubt that every dealer has poor service ;)

I'd be interested as what ones you have experience with as having poor service, especially for all the peeps here in your local area!

Thanks for mentioning that, Gord96BRG.

I have no idea what they mean by a tank. Did they run a full tank to EMPTY?

Originally posted by matt
I average 250-280 per tank. combo highway and city.

last tank. Full to empty

272 miles.
Filled with 13.2
20.6 mpg
approx 50% city 50% highway

Tank before

286
filled with 12.8
22.34 mpg
approx 80% highway 20% city

Best going to Las Vegas
334
filled with 13.3
25.11mpg
approx 98% highway 2% city

Originally posted by Gord96BRG
If you really want to see if it's improved, PLEASE calculate miles per gallon. Miles per tank is so inaccurate as to be almost useless - a "tank" is not a unit of measure by any means.

Regards,
Gordon

Take a look at this post. I'll take a look at my spread sheet tonight and post the averages.
http://www.rx8club.com/showthread.php?s=&postid=88817

For those of you who had service techs shut your car off cold, did you notice whether they revved the engine a bit just before shutting it off?

I was told by my salesman, and have read in postings here too, that if you're shutting your engine off cold, you should gently rev it up to around 5K, and then turn off the ignition. This shuts the fuel pump off while the rotors are still spinning quite a bit, and thus spins out any excess remaining fuel that would cause flooding.

If the techs did that, your car might have been treated better than you realize. just a thought. :)

What dealers are you quoting as having poor service/knowledge on rotaries? I doubt that every dealer has poor service

If your local is letting some"joe ragman" work on your car..find a new dealer.

The master techs in the shop should be the only one trained to work on the Rx8.

The "reflash" on the 8 addresses more than one issue.

P0456- The pressure based evap system was setting the CEL too often due to some oversights from the engineers. This reflash makes the PCM see the "loose gas cap" more than twice before the CEL is set.

P0128- the PCM monitors the actual and requested engine temp and the request was way out of line.

The reflash also inputs different control maps into the PCM for your A/C.

The "learning" capibility of your car is referred to as "short fuel trim" and "long fuel trim" The way you drive the car is constantly being read by the SFT and the averages are calculated to the LFT.
In other words...If you drive your car aggressively for 100 miles. The LFT will learn your driving habits and "bias" the fuel maps towards that. Don't expect to magically get 30mpg on the highway after driving the car hard for a week.

:D

It's good to know that I have a knowledgable master tech so close :) I assume Paul Miller Mazda??

i was just makin it up.

LOL, right!

For those of you not from Kentucky, I offer the following translation:

Originally posted by markpmm
P0456- The pressure based evap system was setting the CEL to often do to some oversites from the engineers.


"...was setting the CEL too often due to some oversights from the engineers.

Sorry, dude, had to jab you. But good insite and eye appreciate your comments.

Thanks

It's the least I can du.

:)

Truly it was.

I averaged 200 miles till E light lit up on 76 gas. I recently tried Shell and got 230 miles till E light lit. I'm trying mobile right now but it looks like its gonna hit the 200 marker since 1/4 was at 50. I think I'm gonna stick with Shell after this. Anyone else try different brands?

Originally posted by Quick2K
I averaged 200 miles till E light lit up on 76 gas. I recently tried Shell and got 230 miles till E light lit. I'm trying mobile right now but it looks like its gonna hit the 200 marker since 1/4 was at 50. I think I'm gonna stick with Shell after this. Anyone else try different brands?

I seem to do slightly better with Shell myself (89).

Shell is by far the best gas, you shouldn't use anything else in your RX-8.

p.s. sorry for the shameless plug....I work for Shell :D

Dropped my car off this a.m. for (1) new oil tray as per TSB, (2) check plugs and old oil since flooding episode (had finally started without any engine work) and (3) first visit service, 3K miles since 7/21 pickup. Also noted MPG 14-15 city, 20-21 highway.

Initially --

-- They questioned whether the early-VIN free service card covers so "early" an oil change. Checked with Mazda. Result: OK but policy is every 6K miles no matter time, so we may have to arm-wrestle you the next time. (I'd noted that when **I** have to pay, they tend recommend every 3 months or 3K miles!)

-- They called back to ask whether low-oil light had ever come on. Said no, but I understood dealers would replace tray per TSB for low VIN cars if customer requests. Result: OK

-- They called to advise car is done, tray replaced and spark plugs replaced. Also reflashed the PCM -- which I did not ask for. Hope it is an improvement, as my CEL light has never come on!

Will advise whether it pays to be such a squeaky wheel.

Did they say why they reflashed? Is there a TSB or what specific problem were they attempting to fix?

Originally posted by 8_wannabe
Did they say why they reflashed? Is there a TSB or what specific problem were they attempting to fix?

When I picked up car tonight, before I could ask, they said that they have to reflash whenever they replace the oil tray. (Wonder if they monitor us here ....) I don't recall that being part of the TSB we've seen but haven't gone back to check.

On my way home and subsequent short trip, no lights went on that shouldn't have. Car felt about the same, though I didn't want to ring it out on same day they re-sealed engine. Idle seemed a bit rougher, but could be that idle point is very slightly different. (Actually, feels very much like it did when I took delivery.) Maybe my fouled plugs had smoothed things out a bit ....

This is the TSB on the reflash.


MIL ON, P0128 AND P0456
Applicable Models
Model Starting S/N Ending S/N
2004 RX8 00000001 40119333

Some customers may complain of the check engine light on at times N DTC P0128 or P0456 may be stored in PCM memory. (Coolant thermostat P0128- Coolant thermostat problem. P0456- Evap System-very small leak detected. Both DTCs may have been set due to incorrect PCM logic. 1. Record FFD on RO. 2. Reprogram PCM using WDS. Update WDS to V27.8 if necessary. Automatic transmission file name = SW-N3H4EK000 Cal. P/N N3H4-18-881K Manual transmission file name = SW-N3H6EK000 Cal. P/N N3H6-18-881K 3A. P0128- Check operation of the thermostat according to the workshop manual.(Section 01-02-52) If ok, proceed to step # 5. 3B. P0456- Perform WDS EVAP LEAK test. If no leak is detected (no DTCS P0442,P0455,P0456) after system test, proceed to step # 5 If leak has been detected, proceed to step # 4. NOTE: DTC P1260 may be displayed while running the WDS EVAP self test. P1260 is an immobilizer system problem code. It may intermittently set when information is not sent to the PCM from the RKE module during the EVAP test. The WDS will display "test failed" when test has completed. This message in most cases is false. If there are no EVAP codes after test has run,(or error message is displayed) no leak has been detected. This can be confirmed by checking MODE 6 EVAP test data. The MODE 6 results will change after every EVAP test has run. MODE 6 data displayed as green is ok, while red indicates a problem. 4. Check system for possible leaks according to workshop manual.(Section 01-02-101). 5. Confirm repair.

This is the TSB on the oil pan. Check the dealer for the part number before you go in for repair.

Mazda Repair Information

--------------------------------------------------------------------------------

LOW OIL LEVEL LIGHT ON BETWEEN 4500-4800 RPM
Applicable Models
Model Starting S/N Ending S/N
2004 RX8 00000001 40111043

Some customers may complain that the low oil level light comes on while driving with engine RPMs between 4500-4800 RPM. Customer may check oil level N find it is within specification. (Between L N F) Normally, the low oil warning light illuminates at or near the L mark. The cause may be due to the engine's oil pan baffle N oil level sensor design. A modified oil pan is available to repair customer concerns. Follow the repair instructions below: 1. Check oil level N note on repair order. 2. Duplicate concern by driving vehicle between 4500-5000 RPMs. 3. If low oil light illuminates (oil lamp icon) with actual oil level 25% above the low mark, replace the oil pan assy. 4. Refer to section 1-11-6 for oil pan replacement. (NOTE: No gasket is used, use Mazda Sealant P/N-8527-77-739) 5. Confirm repair N add engine oil if necessary. PARTS INFORMATION: N3H8-10-4AXA
--------------------------------------------------------------------------------

wait 10,000 milles or so, and mpg should get better. My friend has FC, and he got a new motor, and afetr 10K..15K miles... the gas got better he said.

well i just got my pan replaced and also got the reflash for the p0128 code that was stored in my pcm.my car now has 11,150 miles and has been flawless other than the occasional oillight above 80 mph.i have had no cel or has never flooded and starts great even after sitting night after night in are -15f alaskan nights.my mpg is 19.5 with a one time high of 20.3 and very worst of 17.2,im not sure what to excpect from the reflash and have only drove home the 50 mile commute but my wife and i both agree the car seems to feel smoother if thats possible cause mine has always been super smooth.im a very aggresive driver and would like my pcm to relearn that driving style but are road conditions wont allow it for a while,ill just have to wait till spring and install zoomers stage 1 and rally for a weekend.

wiat what was a joke?? the battery restart or somethign else??

Originally posted by Jag
Shell is by far the best gas, you shouldn't use anything else in your RX-8.

p.s. sorry for the shameless plug....I work for Shell :D


I went to what I thought was a Shell station tonight but the tanks said Texaco. The attendant explained that Texaco and Shell are the same company now. Is this true? And is the gas exactly the same? Will I get improved mileage just the same with the Texaco?

I never use Shell gas - it comes from the mid east - I use Citgo - comes from South America, and the RX-8 runs fine on it, plus Shell is more expensive than Citgo!

i'm just curious how this battery unplugging has been proved or stated by mazda.

Look, Road and Track observed 19mpg on their test of the RX-8. Their observed mileage is usually quite a bit lower than city since their driving consists of 0-everything tests, skidpads, slalom, and general pounding of the car.

They also ran a 14.5 at 95.6, and their 1/4 usually aren't that great. They list a 13.1 for the Z06 for Christ's sake.

If there is the slightest doubt in anyone's mind that their car is BROKEN, then you need to get your head examined.

I am actually pretty damn upset with Mazda. I have been following the car since the RX-evolve concept, and have read or watched any material I could get my hand on. This should have never happened, and lowering the car to 237 is a BS "fix". Most US models are putting 190 to the ground at most, and Mazda does not have lossy manual transmissions.

What is amazing is that everyone is happy with the car, and it is selling fine, despite the missing 30hp (yes it is missing at least 30hp), and about 6 mpg (which is what I believe it is capable of).

Hell, if I had to buy a car right now, it would undoubtly be the RX-8. It is truly a testament to Mazda engineering. They just know how to make a car fun to drive. Drive a 6s and you would never know it was powered by a Taurus.

But like hell if I am going to drive a car that gets 12 mpg, unless it has 16 cylinders and 4 turbos on it.

I really don't understand why Mazda did it. The emissions theory doesn't make sense, because a richer mixture would cause more emissions from my understanding.

But the car that Road and Track had is capable of 13's and 26 mpg on the highway. That is the RX-8 that I want.

The HP issue Mazda can dance around with BS crank vs wheel arguments, but they can't avoid the mileage. A full highway trip should not be 15mpg, when the sticker on the car says 18-24, regardless of how fun the trip was.

Please, don't be happy with your 13-17 mpg, take your car in and complain. I want this issue fixed, and if everyone keeps buying it and loving it as is, it won't get done. At least not by Mazda anyway. The chip Canzoomer is working on is a testament that your car is broken, and while it is great, I am pretty sure it will void the warranty.

Please help. I want an RX-8 so bad, but I don't want the RX-8 I test drove two nights ago.

Originally posted by syntrix
first of all, I don't think you own an RX8, so your posts are very subjective, and not quatified personally. Second of all, I get about 11 mpg, but I floor it all the time, so I deserve it! Other gassers, I would get about 15 mpg on other turbo cars, so the RX8 is not that far off.

What dealers are you quoting as having poor service/knowledge on rotaries? I doubt that every dealer has poor service ;)

I'd be interested as what ones you have experience with as having poor service, especially for all the peeps here in your local area!

I own both a 3rd gen RX7 and an RX8. My 350 HP rx7 gets better gas mileage. The last time I checked the highway mileage in the rx7 it was right around 23 MPG. I don't think I have gotten over 18 with the RX8 and I have heard others on the forum claim around the same gas mileage with the RX8. When I am hard on the throttle, both cars get around the same mileage (about 12). I honestly think there is a lot that can be done with tuning the RX8 to give it a few extra miles per gallon. Only time will tell as the RX8 crowd is now beginning to experiment with piggyback fuel computers.

The comment djantlive made about poor rotary knowledge by dealer service departments is something all too familiar with previous rx7 owners. It seems to me that mazda has educated thier mechanics a little better than they did 10 years ago concerning the rotary engine. Again, only time will tell...

23mpg.. jesus..

My 93 gets 20 at best, and im only putting 300 to the rear wheels. Who tuned your car? What ECU are you running. I do agree with you though, I love the rx8. I just dont understand how its getting such horrid milage when my FD running 13 psi does better.

Ill tell you what though, with the AC on and driving around town boosting off every street light, you can literly watch the needle drop. On Saturday night I get about 8mpg.. lol

The 23 MPG that I recorded was mostly cruising (off boost) while I was driving home on I-95 from a trach event. I tuned closed loop mode simply with an inexpensive autometer A/F guage. I am using a haltech stand alone ECU. A wideband O2 meter is a must when tuning open loop (WOT) maps, but all you need is a stock O2 sensor to tune closed loop maps. What does your setup consist of?
I am very eager to mess with some of the closed loop maps in the RX8 in an effort to increase fuel mileage a bit, but I must wait until the warranty it up. :(

I used to get 120 miles to a tank.

With the grounding mod and de-screening the maf, I'm now getting about 160 a tank.

What does that mean? Probably nothing at all, since I do drive very hard all day long, and most of you all won't push corners or go WOT where you can!

I just had my car at the dealership this past weekend and I had that code as well as the crack sensor code. I am getting a updated reflash on Monday.

Originally posted by syntrix
Probably nothing at all, since I do drive very hard all day long, and most of you all won't push corners or go WOT where you can!

Well I do. I push all safe corners (meaning if I lose it I don't do too much damage) and try to WOT as often as possible!

Edit, my mpg is typically 13-17.

Ok, I changed my oil for the second time last weekend, and have burned two tanks of gas so far. The only differences are:

1. larger oil filter
2. higher miles
3. colder weather
4. descreen the maf mod


I drive hard. period! I'm WOT or pushing the limits of the tires in almost every corner. Usually I get about 11-12 mpg, and I deserve it! On the last tank I got 16 mpg. If I'm due for failures, I'm the poster child ;)

The weirdest thing is that I filled up to the full mark on the dipstick. Normally at this time, I would be about 1/2 way down on the dipstick or more. That's the trade off in driving hard all the time.

I'm about 2mm down from full on the dipstick. :D

I just wanted to share this, it could be a lot of things, but I think owners have reported lower oil consumption as the miles get higher, and better MPG as the miles go up!

so far so good! I'd have some data from the wideband, but I think my low 9v battery caused the data to become corrupt on the LM wideband unit download. I'll reset/recalibrate tomorrow and see what I can get out of it!

Anyone else getting good results over time on their Renesis?

ok -- my ex bought the 93 rx7 and claims that he had recurrent problems with hesitation at lower rpms and poor gas mileage. he claims that nothing was fixed until he finally put in a new ECU himself. he's concerned that some of the new rx8's have this same kind of defect and that we should all be demanding the following:

1. a reflash
2. if that shows no improvement, a new ECU
3. if that shows no improvement, a reflash
4. if that shows no improvement, file suit within the protection rights of the lemon law.

i do think that mazda should take this problem seriously. just because it's a great car, doesn't mean that they can pass on produced cars (from what i can gather, about half of them) with faulty ECU's that end up costing up bucks every time we fill up at the station. the car is advertised to get 18-24. it should get 18-24. not 12-15.

well ... what do you guys think?????

You're right, the 93 did have a documented mpg and 3500 rpm hesitation. It was very noticeable, and a few cars here in ca were lemon lawed back to the dealers for it. The problem was eventually solved by mazda and dealers were fixing them (As I remember it turned out to be a solenoid in the twin turbo vacuum spider). The easiest way to expose the problem was to install a boost gauge and show that the car wasn't making proper boost. But still today there are people living with it because there was no stock boost gauge in the 3rd gen to explicitly point out the problem.

Regarding the Rx-8 I did have mazda document a complaint and I'm sure others did as well. Though it seems to be their modus operandi to release 1st year cars with low hp and poor mpg (2nd gen rx-7 six port actuators, 3rd twin turbo vac spider, miata ecu, mazdaspeed protege ecu).

Originally posted by balletsushigirl
what do you guys think?????

I agree 100%. Maybe we need to organize ourselves in how we respond to this. My greatest complaint is lack of communication from Mazda. If they said they were working on it, I would be happy. I am a patient person when treated respectfully. But not knowing whether they're doing anything leads to dissatisfaction.

Originally posted by 8_wannabe
I agree 100%. Maybe we need to organize ourselves in how we respond to this. My greatest complaint is lack of communication from Mazda. If they said they were working on it, I would be happy. I am a patient person when treated respectfully. But not knowing whether they're doing anything leads to dissatisfaction.

i completely agree.
anyone willing to help us organize???
anyone know what to do?

Originally posted by balletsushigirl
it absolutely WAS NOT warmed up. the guy started it up, moved it like 20 feet, shut off the engine. i was pissed off. more so, because when i dropped it off, i asked specifically that this NOT be done.

-BSG

I just had mine in for service yesterday, (reflash of the ECU), and the mechanic reminded me of the importance of starting, running and stopping the car while cold - don't do it.
Yea, I told him, I'm aware of that. I asked if the way that I start the car is acceptable; which is to not touch the accelerator pedal until the car is warmed up, to which his response was; "...there's a lesser chance of flooding it that way..."
If I were in your place, I'd go back to the dealerships service manager, and stop just short of becoming beligerant. Then remind him that when Mazda sends you the survey about the warranty visit, that you are going to make sure to include this little matter on there.
This is one way to get the dealerships to listen; when they are faced with the threat that they may get a negative feedback form, it seems that they will do whatever it takes to avoid this. Having dealt with five different dealerships when deciding from which one I was going to purchase from, and now two different service departments, I can definately make this statement.:D
Then there's always: http://www.mazdausa.com/MusaWeb/emailMazda.action :D:D
I have written to Mazda via this link before, and they did respond in two days.
Good luck, BSG!
-Doc:cool:

And all I did was change from Chevron 91 to Shell 91.

After using Chevron and getting 23 mpg, I swithced to Shell and it went to 18 mpg. My butt dyno says it's slower too. I am going back to chevron to verify it's the gas and not my head toying with me.

Any thoughts?

matt,

I think you should "change your name" before you get in trouble. But it's probably correct. I'm sure she woudl leave you too for "faster" pastures.

As for the post, I'm getting the average low numbers most have talked about here and I use Shell gas exclusivly. With the exception of when I filled up leaving the dealership. They offered to fill it up for free at a local "no-name" gas station. I refused and went the the first known station. So I'm in the Shell low milage group. I don't even know if we have Chevon dealers around Indy ???

hmm I use Shell exclusively as well. I just got my car back from the dealer where I took it in on a complaint about gas mileage. They road tested it and concluded that the gas mileage was ok. When I asked what gas mileage they got on their test, oddly enough they didn't know ! :)

I will try chevron a couple of tanks and post if I see a change.

Originally posted by doccable
I just had mine in for service yesterday, (reflash of the ECU), and the mechanic reminded me of the importance of starting, running and stopping the car while cold - don't do it.
Yea, I told him, I'm aware of that. I asked if the way that I start the car is acceptable; which is to not touch the accelerator pedal until the car is warmed up, to which his response was; "...there's a lesser chance of flooding it that way..."
If I were in your place, I'd go back to the dealerships service manager, and stop just short of becoming beligerant. Then remind him that when Mazda sends you the survey about the warranty visit, that you are going to make sure to include this little matter on there.
This is one way to get the dealerships to listen; when they are faced with the threat that they may get a negative feedback form, it seems that they will do whatever it takes to avoid this. Having dealt with five different dealerships when deciding from which one I was going to purchase from, and now two different service departments, I can definately make this statement.:D
Then there's always: http://www.mazdausa.com/MusaWeb/emailMazda.action :D:D
I have written to Mazda via this link before, and they did respond in two days.
Good luck, BSG!
-Doc:cool:

thanks for the link.
everyone else should consider using it to report dissatisfaction with their low MPG. maybe lots of noise will spur some response.

-BSG

Well Gents here is the verdict. I did these three things in the past week.

RP Midpipe w/O2 fooler
Grounding Cables
Lighter Volk TE37 18x8.5

My Gas under hard driving went from avg 14 MPG to 17MPG.

Not huge, but I am definately happier about one free trip to work and back. Anyways... my greddy exhaust should be here next week, and I will let you know if this gets any better. Oh and it appears that getting a stainless steel clutch line has resolved most of my 1st to 2nd gear shift issues.

Slavearm

Just sent my report/opinion.
12 mpg does not sit well with me.

Oh yeah- I forget to add this:
I've seen lots of posts about flooding and warnings about short trips or start/stops for fear of flooding.

I paid $32k for a car!!!!!!!!!!!!
$32K can buy a home in some places!
I depend on this car to transport me wherever I choose to go without any problems.
Thankfully, I have not had any of the flooding problems otherwise I would take it back to the dealer and tell them where to shove it!!!!!
Sure, anyone can argue that the early rotaries were finicky but it's 2004. If Mazda could not get it right now then then they should not have sold this vehicle to the masses. They should have lowered production and marketed it to the enthusiasts instead.
My 94 RX-7 twin turbo got better MPG and was more fun to drive. What advancements have they really made?
My 2004 RX-8 is fun to drive but.....12 mpg??????????
Pulease! I could have bought a big-ass Hummer if I wanted to burn the gas away.

I'm on my 4th tank of gas now. At 12MPG the EVO dealers will be seeing alot of me and the Mazda dealer will be feeling my wrath.

Originally posted by balletsushigirl
everyone else should consider using it to report dissatisfaction with their low MPG. maybe lots of noise will spur some response.
Just did the same. Thanks for the suggestion.

Originally posted by GTF-RX-8
Oh yeah- I forget to add this:
I've seen lots of posts about flooding and warnings about short trips or start/stops for fear of flooding.

I paid $32k for a car!!!!!!!!!!!!
$32K can buy a home in some places!
I depend on this car to transport me wherever I choose to go without any problems.
Thankfully, I have not had any of the flooding problems otherwise I would take it back to the dealer and tell them where to shove it!!!!!
Sure, anyone can argue that the early rotaries were finicky but it's 2004. If Mazda could not get it right now then then they should not have sold this vehicle to the masses. They should have lowered production and marketed it to the enthusiasts instead.
My 94 RX-7 twin turbo got better MPG and was more fun to drive. What advancements have they really made?
My 2004 RX-8 is fun to drive but.....12 mpg??????????
Pulease! I could have bought a big-ass Hummer if I wanted to burn the gas away.

I'm on my 4th tank of gas now. At 12MPG the EVO dealers will be seeing alot of me and the Mazda dealer will be feeling my wrath.


Relax

your gas should improve by 2k miles
I have 9k on my car and average 18 mpg
if 18mpg is too low then you may not enjoy the rx8

MikeB...

What happens at 2k that makes the difference.
18 MPG is decent. 12 MPG is too low.

BTW- I'm relaxed :)
Just felt that I needed to vent.

Sent my 2 cents to http://www.mazdausa.com/MusaWeb/emailMazda.action
last night.

Here is the response:

Dear Gary,

Thank you for contacting Mazda North American Operations. I appreciate
the opportunity to respond to you.

I am sorry to hear of the concern you are having with your RX-8.
Please understand lower fuel mileage averages can be expected due to
many factors including fuel type, climate, road conditions, tire
inflation and driving style. The EPA estimate is done under ideal road
and driving conditions. If you feel that your fuel economy is not
effected by any of these factors and that your vehicle is consuming
fuel excessively, contact a Mazda dealership to have it inspected.

Again, thank you for contacting Mazda. It has been my pleasure to
assist you. Please feel free to reply to this message with any further
questions or comments.

I didn't change anything at 2k
my mileage just got better
may have been a flip in the ecu but I have nothing to proof that.

just hang on there and it mpg should get somewhat better

My response is crappier than yours. They basically said they weren't technically qualified to address the matter.

Dear John,

Thank you for contacting Mazda North American Operations. I appreciate the opportunity to respond to you.

In regards to your question about the fuel consumption, please
understand I'm not technically trained and therefore not in a position to diagnose or instruct on repair procedures for your 2004 Mazda RX-8. For these matters, Mazda relies on the factory-trained technicians at authorized Mazda dealerships to diagnose and repair concerns that may arise with a Mazda vehicle. I would recommend calling your dealer regarding a fuel consumption concern.

Each Mazda dealership has access to Mazda's Quality Assurance
Department via a technical hotline. This is offered to each dealership should they need assistance from Mazda with diagnosing or repairing a Mazda vehicle. At this time, there has not been an announcement made about reprogramming the ECU.

Again, thank you for contacting Mazda. It has been my pleasure to assist you. Please feel free to reply to this message with any further questions or comments.

Post pics of ure car!!! Im thinking of getting those exact volks

Are those mag volk's or regular ones?

What size did you choose for your s03?

...

I've been wondering about going up to 245/40r/18 s03,
but then I add about 2 pounds of weight on each tire.

Perhaps 16" is the way to go for performance.. ugh..

/twospoons

I am wearing 245/40/18s front and back. We test fit and were able to get 275s on those rims. They stuck out a little. 2lb heavier wheel 4.5lb lighter rim... dunno I like the stickyness of the S03s. Much more predictable.

Just the regular ones. Not Mag. the mags are like 11.x lbs I believe.

did the tires come with a pressure sensor?

would be sweet to see some pictures of that configuration :)

can you get some behind / front / side shots? :)

/twospoons

I have heard a lot about the reason there is such a wide range in the fuel economy.
I have heard the ECU keep the mixture rich which is why the FE is so bag when the car is new and gets better as you pack on the miles. In my case I started around 14 MPG and was averaging 16+ mpg around town. But on a recent trip to the Bay Area my fuel economy got better and better with each fill up. It went from 17.5, 18.3, 18.8, and 19.6 MPG. I have also heard that the people who were getting there engines replaced due to the seal leak were getting remarkably better power and fuel economy. Still there are other out there who seem to have the phenomenal mileage up into the 30 MPG range. It would be interesting to see where the rest of you are. Can you please give Manufacture date, Mileage, and MPG. So I can start a log?

If you do a search you will see that a very detailed thread on this subject has already been started. It would be nice if it was a sticky to make it easier to find.

Originally posted by my-t-im
:)