View Full Version : MPG after L re-flash


artmt
03-29-2004, 03:08 PM
I had the L re-flash done a few weeks ago and it does seem to improve MPG. Here is what I am seeing:

My daily commute (20 mi each way) consists of:

10 mi highway
2 mi city – slow moving traffic and frequent stops
8 mi “parkway” – 45-55 mph with 3-4 stops

With the old maps I was getting 15-16 mpg doing normal driving and 17 mpg doing very easy driving (shifting < 3K RPM, except on a highway where I stay between 3500 and 4500 RPM).

After the L re-flash I am getting 19 mpg driving like a grandma and 17 mpg driving normally (enjoying the car but not driving it nearly as hard “as if I sole it”).

Air Force RX8
03-29-2004, 03:34 PM
I have not kept track of mileage since that is not the reason I purchased a sports car. My theory being if I can't afford the gas I can't afford the car.

I have had the "L" reflash performed and my experience is that it runs a lot, and I do mean A LOT smoother at cold idle and first gear takeoffs. Whether or not Mazda admits that it adjusts the fuel mixture to be more lean, it sure has had that effect on my 8. I love my baby and wouldn't trade it for anything else on the road.

My .02

artmt
03-29-2004, 03:57 PM
I like the car a lot and I would have bought it even if I knew about the gas mileage and HP.
I don't know about you but it does affect my overall staisfaction with a product when it fails to perform as I was led to believe it does.
The 8 is a great car, but that alone is not enough to owning it a great experience.

cruzdreamer
03-29-2004, 05:35 PM
I have my car in the shop...huge hole in tire and broken tire sensor monitor. I told them I wanted the "L" flash done since I have experienced flooding, hesitation & poor gas mileage. He said he would see about it...it may already have been done on my car. I got mine in November...built in August.....anyone know if my 8 would need the L flash or were they updated by then? I want to see improvements in these areas and want something done. Thanks for any help on this.

Baller
03-29-2004, 05:47 PM
Since the "flash" my MPG remains the same......12 MPG driving hard all the time.
The idle is rougher, but it screams now.
It is faster........but.

The Baller

RX Guy
03-29-2004, 06:18 PM
cruzdreamer, mine has an August built date also and it did not have the "L". I did get the "L" last week and was able to confirm with the 20 pump pedal test.

weiweiwei
03-29-2004, 07:04 PM
do most of the ones being sold now have the L?

trinity77
03-29-2004, 07:08 PM
Originally posted by Air Force RX8
[

I have had the "L" reflash performed and my experience is that it runs a lot, and I do mean A LOT smoother at cold idle and first gear takeoffs. Whether or not Mazda admits that it adjusts the fuel mixture to be more lean, it sure has had that effect on my 8. I love my baby and wouldn't trade it for anything else on the road.

My .02 [/B]

I have notice much smoother running as well. I wouldn't trade it for anything else either!

AlexCisneros
03-29-2004, 07:19 PM
Before the "L" Re-flash, I'd get about 10MPG

After, about 13MPG... not too shabby





oh yeah... I drive it like I stole it ;)

artmt
03-29-2004, 07:20 PM
do most of the ones being sold now have the L?

The service bulletin on the L flash came out about a month ago. If the new maps went into production at the factory at the same time then out of new cars on dealer lots very few if any at all would have it.

MaHogoff
03-29-2004, 07:53 PM
Well, then.

In summary, requesting the "L-Flash" seems risky business. I do notice a little jitter at cold startup that goes away once in 2nd gear once baby gets a little juice. So the hell with it. My 8 runs like a top, ...and what kind of Type-A even keeps track of "mpg" in a LOVING CAR LIKE THIS ? :)

orangematics
03-29-2004, 08:17 PM
I used to get around 14mpg. now, after the "L" flash i am getting around 18mpg!!1

Kagero
03-30-2004, 12:05 AM
I may have missed it but has any body noticed how the "L" PCM has changed the auto 8? MPG or performance?

srm858
03-30-2004, 08:48 AM
Still on the first tank after the flash. MPG seems to about the same, 19 mpg. It's frustrating that my friend's Honda Pilot with a V6, AT, and about 1500 more pounds than the RX8 gets 21mpg in similar driving. Now, I hate driving the Pilot, but there is no question the RX8 gets crap MPG. I'm still hoping the flash will improve the mileage, because one tank is not enough to give a good indication. If I could get in the low 20's with mixed driving, I would be happy.

klegg
03-30-2004, 11:01 AM
First 1/2 tank with reflash, seems to be an improvement. Will know for sure this tank, I will post what I find.

f1michel
03-30-2004, 01:10 PM
srm858, i think that 19 mpg is pretty good compared to many. i got 21 mpg driving like a complete moron , respecting ALL the speed signs... i will never ever get that kinda mileage in my live because i was bored to death !!!

derwankel
03-30-2004, 01:19 PM
srm858 said :
Still on the first tank after the flash. MPG seems to about the same, 19 mpg. It's frustrating that my friend's Honda Pilot with a V6, AT, and about 1500 more pounds than the RX8 gets 21mpg in similar driving. Now, I hate driving the Pilot, but there is no question the RX8 gets crap MPG. I'm still hoping the flash will improve the mileage, because one tank is not enough to give a good indication. If I could get in the low 20's with mixed driving, I would be happy.


Yeah, well let's see how your friend's Pilot carves up a road course ... most likely like a dull spoon ... I'll take the knife-edge reflexes and cutting edge style of the RX and give back a few mpg any day

SDLinus
03-30-2004, 01:34 PM
Newbie here...can someone explain the background for the "L" flash...

srm858
03-30-2004, 01:58 PM
Derwankel, no question the Pilot drives like a whale. I love driving the RX8, that's why I bought it. I would like to see a technical explanation as to why rotary engines get worse mileage than a comparable piston engine. They seem like they would have less friction and with the new Renesis design eliminating the intake/exhaust overlap, the engine should be efficient. I traded in a BMW 528i, 5-speed and that car would get in the low 30's for mpg on straight highway driving. It had less power than the RX8, but it's heavier and had way more torque.

The rotary has a lot of advantages. Small size, smoothness, high rev. ability, but why the poor mpg? If anyone can explain this to me, I would love to know.

Oh, by the way, just filled up the tank after the L flash. This first tank yielded 18mpg. About where it normally has been. Although my wife drove it over the weekend and she always revs the daylights out of our cars, so the mpg could be pessimistic.

derwankel
03-30-2004, 04:13 PM
Well I am no expert, but I do know Mr. Wankel developed the engine for it's simple design, few moving parts and by extension, reliability. The original single-rotors (NSU Wankel Spider) got decent mileage (27 mpg) and would rev in the 8K rpm range (or 12K racing form). At 497 cc it made 50 BHP and 54 lb ft of torque. The current rotary is quite a bit larger, produces quite a bit more power, and consumes more fuel to accomplish these tasks. Original reliability was a serious issue, today's reliability is far better with cars exceeding 200K miles when properly cared for... more in line with Mr. Wankel's original hopes I should think.

But I digress ... there are others here who can better explain it, and I am sure it resides in these hallowed threads somewhere, but essentially, the shape of the combustion chamber is not by any stretch of the imagination an optimal design for "efficiently" burning fossil fuel. The distribution of the energy created with the ignition of the air/fuel mixture in a cylindical chamber is far more efficient. That is why cannons and firearms of all sorts utilize a cylinder to contain, compress and control the escape of the gas to accellerate a projectile ... sometimes called a piston in the automotive world ... and we ain't got no pistons here ;-)

RenesisPower
03-30-2004, 06:39 PM
According to Mazda the re-flash is to help with the flooding problem and has nothing to do with gas mileage.

For owners who think they are getting better gas mileage consider it the placebo effect. There are so many factors in gas mileage that nobody can prove better or worse MPG, ambient temp, accelration rate, weight of the car with cargo, passengers, amount of highway vs. street driving, etc.

We just gotta live with the pothetic MPG of this car, kind of bad since I got 13 MPG on my last tank and in my area (Southern California) we pay $2.45 per galon of 91 octane gas.

So be it, I still enjoy driving this car.

Pinhy
03-30-2004, 07:10 PM
what about the new "M" flash that they are talking about now?

srm858
03-31-2004, 07:43 AM
derwankel, thanks for the explanation. Combustion chamber design is certainly important for efficency.

I just had my PCM reprogrammed, but I don't know whether it was the L or M flash. The info. from the dealer does not specify. I can't tell the difference in the way the car runs, but the CEL no longer comes on. My wife had problems starting it, but I have had no issues.

What I need now is an extended period of not bringing the car to the dealer or not starting. I need to build some confidence again in the car. It's great to drive and I enjoy every minute in it.

Preacher
03-31-2004, 10:55 AM
The dealer's doing my 'L' re4flash and any other catchup work,on Monday....I'll post my obs next week....

artmt
03-31-2004, 11:19 AM
According to Mazda the re-flash is to help with the flooding problem and has nothing to do with gas mileage.

According to Mazda the 8 averages 18/24 mpg. I don’t expect them to say that re-flash fixes the problem they claim does not exist.

For owners who think they are getting better gas mileage consider it the placebo effect. There are so many factors in gas mileage that nobody can prove better or worse MPG, ambient temp, accelration rate, weight of the car with cargo, passengers, amount of highway vs. street driving, etc.

Machines are not susceptible to placebo effect.
All these factors average out over time. Tracking gas mileage for 500 mi before and 500 after should provide a reasonable indication.
We do know for a fact that the new fuel map is leaner – read Canzoomer threads. It is of course possible that better gas mileage is the unintended consequence of the flooding fix, but who cares.

Reeko
03-31-2004, 11:42 AM
Originally posted by artmt
According to Mazda the 8 averages 18/24 mpg. I don’t expect them to say that re-flash fixes the problem they claim does not exist.

Machines are not susceptible to placebo effect.
All these factors average out over time. Tracking gas mileage for 500 mi before and 500 after should provide a reasonable indication.
We do know for a fact that the new fuel map is leaner – read Canzoomer threads. It is of course possible that better gas mileage is the unintended consequence of the flooding fix, but who cares.

Yes, but there are other factors.
For example, I have recorded a significant MPG difference (2MPG) between cold weather (30s-40s) and warm weather (60-70) driving.

So, some people might be observing an increase in MPG due to warmer weather. Also, places should be getting away from winter fuel blends (10% alcohol here in OR), this should also increase milage.

RenesisPower
03-31-2004, 01:38 PM
Mchines are not suseptible to the placebo effect but machines do not post such comments here either, the drivers do and they are very much suseptible to the placebo effect.

Also keep in mind the EPA mileage ratings are based a fixed procedure and is used for "comparison purposes" only, they are in no way a defenitive number for true gas consumption of a car.

artmt
03-31-2004, 01:40 PM
Yes, but there are other factors.
For example, I have recorded a significant MPG difference (2MPG) between cold weather (30s-40s) and warm weather (60-70) driving.

So, some people might be observing an increase in MPG due to warmer weather. Also, places should be getting away from winter fuel blends (10% alcohol here in OR), this should also increase milage.


True, except that here in MA the weather has not changed much since the middle of February. With exception of two warm days it has been in the 30s and 40s. And we are probably still using winter gas. I will check for further improvement when it gets warmer.
I am pretty confident about attributing the improvement to the re-flash, especially considering that the new fuel map is leaner.

artmt
03-31-2004, 02:39 PM
Also keep in mind the EPA mileage ratings are based a fixed procedure and is used for "comparison purposes" only, they are in no way a defenitive number for true gas consumption of a car.
I know that EPA uses an odd indirect procedure and the number is not supposed to be a precise measure of true gas consumption. However for the vast majority of the cars EPA’s numbers turn out to be close enough to the actual consumption so that consumers reasonably use them as an estimate.
It is possible that because of the 8’s unique design EPA numbers are so wildly different form the actual mpg. In that case Mazda should have disclosed this fact.

cruzdreamer
03-31-2004, 03:15 PM
Ok...just got L flash on my car yesterday....seems rougher when cold but smoother and better with a slight increase in power...or so it seems. Gas mileage is yet to be determined. What is the 20 pump brake test? Do I need to do that? Help out and inform this young lady!!!

8_wannabe
03-31-2004, 04:53 PM
Originally posted by RenesisPower
For owners who think they are getting better gas mileage consider it the placebo effect. There are so many factors in gas mileage that nobody can prove better or worse MPG, ambient temp, accelration rate, weight of the car with cargo, passengers, amount of highway vs. street driving, etc.
Over the course of ownership (8 months now) I have tried every strategy for improving mileage: different octanes, driving styles, shift points, fuel brands, etc etc. No matter what I do, I get 16.8 mpg. Sole exception is long road trips (freeway) where I get about 20 mpg.

This makes me think mileage is a function of two factors almost exclusively. One is, how much freeway driving you do. The other deals with when/how your car was made. These two factors alone explain the variations among us, and there is a good thread on statistical analysis that backs this up (with data collection from many owners.)

I just got the L update. I will start tracking mileage. If I get anything other than 16.8 i will attribute it to the reflash, since my ratio of freeway driving is not going to change.

tpryor
03-31-2004, 05:01 PM
Originally posted by cruzdreamer
Ok...just got L flash on my car yesterday....seems rougher when cold but smoother and better with a slight increase in power...or so it seems. Gas mileage is yet to be determined. What is the 20 pump brake test? Do I need to do that? Help out and inform this young lady!!!

The 20 pump brake erases the "keep alive memory" in the car, and allows it to start fresh learning your driving habits. With the "L" flash, you can verify that you have successfully completed the procedure by watching the oil needle "sweep" just past halfway and then back to the left again.

I reset mine before every autocross - if nothing else, it freaks out the competition - they think I'm nuts..........

o_town_racer
03-31-2004, 05:36 PM
I've been flashed twice....no mileage improvements....but it wasn't bad to start with. Still between 17 and 19 city/highway mix and 20 to 23 all highway. Forget about improving the gas mileage and JUST ENJOY THE RIDE. Otherwise trade it in on a Honda Insight or Toyota Prius.

cruzdreamer
03-31-2004, 05:40 PM
Thanks tpryor...I did not know that...ok...will try it.

8_wannabe
03-31-2004, 05:44 PM
Originally posted by o_town_racer
I've been flashed twice....no mileage improvements....but it wasn't bad to start with. Still between 17 and 19 city/highway mix and 20 to 23 all highway. Forget about improving the gas mileage and JUST ENJOY THE RIDE. It's easy to say "Forget about improving the gas" when you're getting up to 23 mpg. For those down in the low teens, we'd like to get where you are and THEN forget about it. btw, if you want to forget about it and just enjoy the ride, how do you know your mileage before/after flash, on/off hiway; sounds like you're monitoring it pretty close.