Has anybody experienced a drop in gas mileage after having the 4206F recall done?

I had the recall done back in December 2006, but then put my car in storage for six months when I left town to finish up grad school half-way across the country. So I didn't start driving my RX-8 regularly again until just this past summer.

I immediately noticed that I was getting 13-14 mpg when previously I was getting 16-18 mpg. At first I thought it was a change in driving habits. I was taking more short trips and getting less highway time.

But since I keep a detailed account of every fill up I've had since I've owned the car, I checked back to compare gas mileage numbers. The lower numbers started right after I had the recall done. And the numbers are consistently lower ever since that time.

So what I'm wondering is:

1) Anybody notice the same problem?
2) Is it possible that the PCM reflash was done incorrectly?
3) Is it possible to get the PCM reflash redone or reversed back to the old one or an even newer one?

I think I might take my car on a long highway drive and just empty the tank, just to see what mileage I get on the highway and settle the question of whether or not it's change in driving style or an actual change in fuel consumption.

 

i remember the recall flash instructed increased fuel injection during idle.
That could be the reason. I also heard that the new 2008 rx-8s were getting 16mpg city stickered on them.

 

finish out the tank. get good gas. reset the ecu. drive it hard...

then see what the next tank brings..

beers

 

The reason 2008 has 16/22 on sticker is because of new EPA test method of MPG. Which across the board all vehicles dropped about 2 MPG to 3 MPG. Hybrid vehicles dropped even more. http://www.fueleconomy.gov/feg/ratings2008.shtml

 

Hate to say it but its most likely your short trips that is killing the mileage since I get the same (but getting progressivly worse ). My own lil theory is that the ECU runs it super rich for awhile then leans out after its been driven for awhile. Its that or your CAT is slowly failing on you.

 

I would tend to agree with this. I drive all city during rush hour "outer Chicago" I have had as bad as 11mpg in winter and as good as 13.5mpg while driving easy in the summer. I was convinced for the longest time that there was something wrong with my car (still am not 100% convinced there is not)

Well Mazda, after a year and half of fighting with them, great customer service, agreed to do a mpg test. There results came out around 21mpg. (I won't go into how they screwed up the math at first) but this was Highway and far suburban mileage. When I drive the highway I get between 18 and 22mpg depending on aggressiveness and speed.

So this leaves me with one of two possible answers. There is something wrong with my car that Mazda can't/wont find. Two, the RX-8 is a horrible city car in terms of mpg. It my be a little of both.

 

I get about 18mpg city, usually 19mpg with a mixed use, but DC traffic isn't really highway miles, and when I took a trip to NC, I had my best tank of 21.4mpg which was all highway.

 

Sure it is not just a winter thing???and that you really have been checking for more than a month or two???

Remember CA reformulates its gas in October through March for emissions, and gas mileage typically drops a couple MPG when that happens.

 

I've been checking since the end of June.

 

How do you reset the ecu?

 

My mileage increased about 1-2 mpg from a consistent 17 around town to 18, and from 18-19 to 19-20 highway.

 

https://www.rx8club.com/series-i-tech-garage-22/ecu-clear-reset-27548/

beers