Just wanted to say "hi". I'm new to this group; have a 6-spd. which I bought approx. 1 year ago. I, too, have been very disappointed with the MPG. For the first 8 months I owned it, I only drove very short distances "in city"; less than 3 miles much of the time. I got somewhere between 11.8-14 MPG. Now driving about 10 miles to work each way and consistently get 14.5-16 MPG. Only did a long trip (~500 miles each way) once - got 20-21 MPG. Took my car in today for the fuel tank recall and asked to have the car re-flashed. (Thanks for all the threads on that!) Dealer said it would MAYBE add 0.2-0.4 MPG and not to get my hopes up. I hope he's wrong!

(I'm spoiled - my Ducati gets 50+ MPG and it's quicker, too!!!)

Lily

 

i just put in a lil over half a tank. so lets say i had about 8 gallons. I drove the car 7 miles to school every morning in city traffic and out of school i would take the highway home. Keep in mind i redlined the car at least a dozen times and some of those redlines were thru 3rd gear . i got a total of 150 miles on that lil over half a tank. thats about 18.75 mpg with a lot of redlining! I just recieved the updated flashes and recall work and my mpg has no doubt benifited, cus before this i was gettin about 15 mpg.

 

o yea, i also have 13500 miles on the car.

 

First MPG check done while around town. 98% city/2% HWY spirited driving, full tank.

13.399 MPG. Watching the needle sink was scary.

Now I'm going to see if I can get under 10! :D

 

Just took my car in for the fuel tank insulation recall. Had it reflashed while I was there ("R" flash). I didn't think it was possible, but based on only one tank, it made it WORSE! I got 178 miles on a tank! Filled up with 13.5 gals - that's 13.2 MPG. Granted, it was all city driving, but YIKES - that sucks!

Lily

 

OK, I stopped using my 8 to commute from work/home, since the MPG of the 8 and the gas price are terrible.
I used to have 14~15MPG before, about 10 miles from home to work and 20 traffic lights in between, stop and go....
I have almost 17MPG now, driving mostly in weekend, mixing highway and city, shifting gears at 3k~4k, driving like a grand mom.
Now, how the hack can I get to the EPA index(24/18?!) Push my car wth the engine off to get the extra mileages?! I mean, I am driving highway/city and driving like a Tercel already?! And I still can't reach 18MPG? I know, some ppl would say "Don't complain about the MPG while you are driving are sport car.....blah blah blah...".
If the EPA showed 19/14MPG before I bought the 8, and I still choose to buy this car, I have no complain. However....... I'm complaing about the misleading EPA index.

 

New record for me... 22.4 MPG! I have no idea why it jumped over 2.5 MPG..

 

I was getting 19 mpg all day and 22 highway but now after my car flooded i can't break 17 i am getting about 15.7 on mixed driving.

 

Thanks for your post - it sounds like you do the same drive to work (or did) as I do; 10 miles each way with way too many lights on the way (probably about 10 or so for me). If I drive like Grandma, I get 13-15 mpg. Last tank, I just said "to heck with it" and drove like I want to. I got 12 MPG!!!!!! I agree - I wouldn't be bitching except that I was stupid enough to actually believe that 18/24 EPA rating on the new car sticker when I bought the 8. True- they're usually misleading, but not by this much, in my experience. I do like my 8, but know I won't own it long because of this. Too bad it's so wet in Seattle. I'd take my motorcycle to work everyday if it wasn't so dark, cold and wet - too DANGEROUS for this biker chick!

Lily

 

Clearing the flood condition can fry your cat if it is done wrong. The mileage change could be due to a melted converter.

 

my low tank is 16.5, average is 18.5, and high is 23.4. last tank had a bit more spirited driving than normal and i still managed 17.8. also just go flashed to the R revision, so i'm interested to see what effects that has, if any.

 

I seem to be getting worse mileage with the "R" flash. Anyone else seeing this?
I just tried a new oil additive that works wonders in piston engines, but if it's doing anything in the rotary, with mileage, it may be the problem, not a solution. I must say, the stuff does make it run like a well oiled clock, so maybe the added fun is adding to the reduced mileage. Even though I feel as if I'm driving the same, I know that speedometer is saying something different.
I almost get the feeling that the later flashes that have added to the low-end torque may be doing this by more agressive throttle application in the drive by wire system. I don't know how the system works, so this may or may not be possible with a new flash. I just know the thing really jumps out from a stop with very little driver throttle input.
I really don't know why I'm so obsessed with mileage, I can afford the gas and this thing is such a pleasure to drive.
By the way - via edit - I was averaging right at 20 mpg in mostly two lane road, semi-country (building up way too damned fast) commuting, now I have dropped to a hair under 19 mpg.

 

I just filled up for the first time in my new 2005 MT 8 today. I'm hoping the 13.8 MPG improves with time! I've been driving 80/20 city/highway miles and TRYING to be good about keeping the engine under 4k rpm during the break-in period. I'll try keeping it under 3750 rpm and see if that improves things.

 

Hi, first post here. I've got about 1000 miles on my new 2005 MT, and I'm getting over 18MPG. I started checking on the second tank, and even after a day of fun driving through the mountains, I still got a little over 18. Overall, with weekday commuting and weekend fun, I get around 22-ish. Try driving at a higher RPM... 3000 RPM is almost lugging the engine. I almost never drive under 4500 RPM... shift at 6 - 8000 RPM...

 

This is my report on my 2005 6sp.

NYC
30-40 deg.
93 oct.
Normal Driving. 3-4k Shifting
80% highway 20% local.

Milage------Gallons MPG
427---------3.9
481--------13.3------13.8
665--------12.5------13.8
858--------12.9------15.4
1067-------13.2------16.2
1223-------11.4------11.8
1425-------13--------17.7
1642-------14--------16.6
1843-------12.4------14.27
2066-------13.27-----17.98


I am going to use the tripometer and start documenting it too.

Overall, I seem to be gaining a bit. I also have a feeling that driving at higher speed saves gas? (around 70-80 mph) instead of my usual 40-60 due to traffic every day.

 

I don't understand your table. For example, at 427 miles you filed up the tank and it took 3.8 gals. Then 54 miles later you filled the tank with 13.3 gals. That certainly is very poor mileage , so I suspect you transposed some numbers. You should expect to get about 19-20 mpg with that type of driving based on what other owners have reported here on the forum.

 

I only had few bucks in my wallet at that time. 3.8 gal gave me approximately 54 miles. Divide that by 3.8 gave me 14.2.

I hope the formula is correct.
Nedor

 

Ours AT 05 8 is getting better mileage as we get more miles on it. First tank we measured was 18.32 and now with a little or 2500 miles on it, we got 22.8 and that's with an extended drive up a mountain in 3rd gear mainly. I'll get off my "my mileage sucks" kick now

Tim

 

13,000 now on my 6MT. Done quite a few road trips on I-70. So I generally run at about 80mph on the highway. It's getting a consistent 21-22 on the plains (this is complete tanks of fill up, merge, and run till the next gas station.) In the mountains I can get around 24-25. As far as city, I was getting about 20-21 in mixed driving, but since the R-flash it seems to be more like 17. I need to keep an eye on that.

 

OK, I've had my 8 for about two months now. On the last 10 tanks of gas I am averaging 11 MPG in mixed driving. On a few tanks I drove like Grannie May taking her Sunday drive to the grocery store and still only got 11.5 MPG. And, I live in Vegas, so it has been nice weather - usually 50 or 60 degrees ambient temps.

Here are the details of my 8:

MT
22K Miles
no mods
BF Goodrich KDW Tires - 35 PSI
91 Octane Chevron

I think I have the latest flash as I have a service receipt from 10/05 that shows an ECU download was installed.

I know this is a sports car, but 11 MPG is just unreasonable. That's $100 a month extra for gas than I budgeted.

Any ideas? I love the 8, but a 36 foot motor home would get better gas mileage.

Could my cat be damaged? Problematic plugs? Extreme carbon deposits in the engine?

I would like some ideas before I go to the dealer and get snubbed... TIA.

 

I have a sudgestion, im very aware the the rotar is a very unique motor, but what im about to say applys to any fuel consuming applacation. weather you have a large V8that revs low or an Rx8 that revs high, not reving the motor the way it needs to be reved or likes to be reved, Can and does cause carbin build up in the fireing chamber. As i saw on page 1, you dont rev you engin, probley think your saving it, infact every so often, you need to Run it out, make it work. This may help your cace.

 

Well more so for cars with more miles with mileage decressing

 

Ok, im seeing a new topic arise. Witch is the best flash for the update?

 

Greetings!

This is my first post on the boards, but I have been searching/reading/lurking for a pretty long time now. I've been learning all I can about 8's because I am looking forward to replacing my 5th gen Prelude and S/C'd '01 S2000 with one car that covers 95% of what I like about both cars and none of the attributes that I don't. I'm not a complete newb to the "wankel lifestyle" ... but there's always more to know.

That being said. Niether of my Hondas post particularly better mileage numbers than the 8 does, even before I modified anything. I average around 18 mpg in each in mixed use. I have never gotten better than 230 miles to a tank in the Lude and that's my commuter car! There have been plenty of times where I have managed far less than that, but had fun doing it. I guess I don't understand what some of the pump shock is all about.

The same thing goes with checking your oil while topping off your tank ever other gassing. VTEC engines love burning up oil in the higher rpm range. The lude will go through a quart every 3000 miles or so... To me alot of the "quirks" that some feel are annoying in the 8 are just...well...normal

Now to my question. I'm assuming that if I buy new that I don't have to worry about what flash I'm on...it should be M or N as I understand it...however...if I buy a used one, should I have the flash checked by the dealer before I buy it? The deals currrently for new ones are pretty good. I just want to know if it's worht the time to save a moderate amount of money.

Love the site and I can't thank you guys enough for everything I know now before I buy.
Ride on! (and sorry for the book),
Led

 

Great first post! I tend to agree with your comments about obsessing about the "shortcomings" of the RX-8. Mine will be 2 years old soon and I haven't experienced any of that and have averaged 20+ mpg for 10K miles, mixed driving with regular runs to the redline.

An '05 or '06 RX-8 will almost certainly will be up to date. In any case, don't worry about the ECU level since you could take the car to any dealer and have it checked/updated free of charge. The software level depends on which model and which country and/or region of the country the car is operated in. You can see what I mean by going to the Service Bulletins and reading the one concerning a No-start condition. There is a table in that SB that lists the software levels by year-model-region. As an example, for an '04 MT in the US (except for Cali) I think the level has an "R" at the end of the version number and it's, therefore, referred to as the, duh, "R" flash.