JeRKy 8 Owner

For some reasonthe past two weeks I have been getting much better mileage from my Rx8 and I nevergot any reflash applied to my car. This has beengoing on ever since the gas prices shot up. Im now a little over 9000 miles and have always been using premium 93 octane fuel. I have also always been driving 100% city on all the tanks for the most part so this hasbeen freaking me out.

My empty light would usually come on by the time the tank had 200 - 210 miles on it and by the time the tank had been way past empty it would barely reach even 240 miles. Now the light is not coming on until 220 - 230 and by thetime the nozzle has reached the last line Ive had 255 - 270 miles on the tanks. So Ive gone up roughly 1 mpg in 100% city mileage. Iknow this isnt that much but I havent had any change in mileage for the 7 months Ive owned my Rx8 and nowall of a sudden I get this pointless increase in mileage.

Yesterday I went outofmy way to spend at least 30 miles on the highway on purpose to see if the mileage has gone up all around in both aspects. My gas nozzle was already 1 notch below the half a tank notch before I got on the highway and the tank had about 125 miles on it. When I got home I was 1 notch above the 1/4 mark and guess what?? To myhorror -- this tank already had 210 miles on it!! This is unbelievable guys. Thats over 80 miles from half to 1/4 full. Ive never seen my Rx8 pull that off. This current tank will be the best my Rx8 has ever had. I have driven on the highwaybefore but my mileage hadnever been so greatly affected.

I just donot understand why my Rx8 has this sudden increase in mileage. For whateverits worth Im really glad my fuel inefficient car decided to suddenly improve its mileage during these days of disgusting gas prices but I justdont understand why this has happened. The only thing I can notice that has changed is that Ive been using many different brands of gas latelysince all the stations have shitprices but I doubt that would affect the mileage this much. The last time I wasat the dealership back in March I got the air bag recall and asked for the L reflash butthey refused and gave me the car in half an hour w/the air bag problem fixed. I just dont see any logical explanation for why my mileage would magically go up at 8500 - 9000 miles.

murix

I managed to see 24mpg the other day for the first time and I have yet to have a reflash as well. I am pretty sure it had to do with a serious change in my driving style on that tank though. I have been averaging 20mpg on the highway and 14mpg in the city.

I average around 8mpg on the track.

WHealy

JeRKy 8 Owner,

I've noticed inproved fuel economy as well. But I attribute mine to finally reading one of the posts about the defrost mode running the A/C even though the light is out. I'm just used to running the air up agains the windshield until it gets warm. Now that I figured that out, I just keep the unit off until it's warm and blow vent and feet areas.

I know you're somewhere in Florida, but could it be that you are not currently using the defrost mode?

kwescott

I had a similar change in mileage at about 3500 miles. I drive only highway and usually get about 290 per tank. I actually got closer to 300 when I filled up, and needed fewer gallons to fill up than normal. I attributed this to my driving style...less showing off I guess. I had one tank where I didn't even make it to 270. This was after using a gas brand that I had never used before. I attributed it to that. Don't know though.

Xyntax

I usually fill up at 180 - 210. sucks huh?

JeRKy 8 Owner

Ive rarely ever used defrost. Itsalways hot as hell down herein Coral Gables

KrustyKlown

Rotor engines are supposed to improve in MPG as they break in and get older. Unlike piston engines.

80CuIn

Could it be due to the change from oxygenated fuel (used during winter in some states) to non oxygenated fuel?

Al

Ole Spiff

Sounds like you've crossed the magic 15,000km or 9,320.56 mile mark at which point the ECU is programmed by Mazda to adjust it's settings. Some have reported changes in performance/mileage, others have reported no detectable difference (myself included).

I've had my car in for the recalls (I have an early model) but I don't know if the dealer ever reflashed my ECU with any of the mods. My car has always run well and gotten decent mileage; still does. So maybe for owners like me there's no detectable difference at the crossover mileage mark. For other owners who were not getting the best mileage they may see an improvement; sounds like you have.

JeRKy 8 Owner

Our cars are programmed at 9320 miles to adjusttheir settings? What isthe point of that? Andwhat if I were to reset the NVRAM using the 20 brake stomps trick now? Would that ruin this 9320 mile magicadjustment you are talking about?

DAVETHOMSON

Averaging 22.3 mpg going to work and back.

Just done a 1000 mile round trip from Fort Worth to Branson, MO. Sticking to the speed limit, I averaged 23.7 MPG.

Car has now done 6100 miles.

No complaints about the mileage from me.

Mike Ockstynee

Dude, I'm going to appologize first. Sorry for flaming you. Ok, Now thats done.....

You are so full of crap. Please show me any evidence other than "my friends uncle's cousin's gay rodeo clowns dogs owner told me cause his friends mothers uncles cousin is a mazda salesman".

I call BS until I read it from mazda. I'll be the first to say I was wrong, but my guess you will have nothing to support what you just said.

Kagero

I have always noticed and improvment in mpg after the Rotary has broken in. This car when new got 23.5mpg with cruz set at 65mph, now with over 6k I get 27.5mpg. This car keeps getting sweeter. When I dont use the cruz and really enjoy the car on the hwy I get 22.5mpg now. I dont mind getting under 20mpg around town, most of my other RX's got 12-15 in town and 21 on hwy.

Ole Spiff

I tried doing a search in the forum for the topics which were discussed here around November of last year, but I can't seem to find any of them. Canzoomer and others were talking about this when mpg and performance was such a hot issue, and he was talking about his (at that time) upcoming ECU reflash mod.

Anybody remember what forum this discussion was under? I thought it was this one....

Gomez

So much love here on the US part of the forum....I've just finished reading the 7K pitted wheels thread.....you guys need to have a good lie down and restie poo, my kids used to get ratty when they got tired.

Now that I've found an answer to the problem there in the US, I'll add my two bob's worth to this thread.

I was told by the Renesis Tech at my local dealership, that all the models in the passenger car lineup (with the exception of the Miata/MX 5) run rich for the first 20000Km's to assist with running in.

Here in Oz, that's the 2, 3, 6, Rx-8, Tribute 4WD. The MX 5 is an old model and probably missed out on this ECU cal as its near the end of its model run.

MazdaManiac or one of the other rotary legends here on the forum would be able to confirm this, I'm sure. Don't just rely on my info, it only came from a factory trained professional!

Regards, Gomez.

IKnowNot'ing

Dear oh dear.

I actually worked on the Escape/Tribute calibration (on 2.0l only though) when I was at Ford in Dunton, UK. Both Ford and Mazda used the same engines and ECU and strategy. I was responsible for the dyno-based cal and a few colleagues from Dearborn were responsible for it's integration into the vehicle.
I'm very very very very very very very doubtful (to say the least) that there is such a thing as a trigger mileage or a rich run-in strategy. Never heard of that after spending 4 years in strategy books and building the strategy. And I have evidence that it does not exist.
If it did exist, it would be a strategy module specifically designed for rotary engines then!

Gomez

Here in Australia, we only have the 3.0L V6 in the Tribute, so I can't comment on a four cyl version, neither I assume could an Australian Mazda Technician.....As with the Miata, it is possible that the Euro Tribute missed this cal.

As I said, just my two bob's worth....

Gomez.

IKnowNot'ing

The 3.0l V6 iin the Tribute is a Ford Duratec engine calibrated by the same Ford team in the US. They did the cals for all markets, including Japan, Europe and Australia. The RHD models are built in Japan, LHD in Kansas City I think (in US anyway)
I will double check with some guys in Dearborn and Dunton.

Gomez

I'd also be interested to hear their thoughts on any info on the ECU programming in the other models....Timbo has been logging his fuel consumption for over 20000k's...It makes interesting reading....

Gomez.

Carolina8

For what it's worth, I too have noticed a recent increase in MPG with no reflash, etc. I have about 8,700 miles on the car. Used to fill up at about 200-210 miles. Got 275 out of the last tank, and the light wasn't even on.

Based on previous rotary experience, I would attibute it to breaking the engine in, not some magical "trip wire" programed into the ECU.

Reeko

There are 2 other factors that have significant impact on MPG.
Air Temp, and Oxygenated Fuel.

I noticed a masurable difference in MPG when we had significant/sudden swings in temperature here in Oregon. When temps were warm, I was getting 17-18 MPG (hard driving), then the weather dropped about 30 degs average, and my MPG dropped to 15-16 (same hard driving). This is probably due to the ECU richening the mixture for the denser air?

Second, here in Oregon they run a winter fuel (Oxygenated) mix that is 10% alcohol. I noticed a drop in MPG when they switched to it. Not sure when they are going back to summer blend.

Could either of these 2 factors explain the MPG change you are seeing?

Carolina8

Shouldn't apply to my situation. No oxygenated fuel requirements here in SC for what passes as winter. As to the air temp, we've had a very cool spring, and last week was probably one of the coolest, so no appreciable difference in temp (maybe 10-12 degrees.)

JeRKy 8 Owner

Guys Iguess I was wrong about thisafer all. I must have been driving the car ina more civilizedmanner the past few weeks b/c on my new tankof gas today I started driving likean ******* again --more aggressive as usual-- and this tank seemsto be just as bad as the old ones. I guess I willgo in for that reflash on my next oil change