25 MPG in my 8
 

This was in Virginia where radar detectors are subject to confiscation. On the rest of my 4200 mi. trip I averaged 21 to 22 mpg. So some 8's do well if you don't have a led foot.

Yes - it is possible. I average 21-22 combined, but I have hit 24.7 before :)

I've never broke 13 mpg... even with highway driving and no A/C...
I'm stock with M-flash and AT...
I've experimented with 87, 89 and 91 octane...
I seem to get my best mpg with 87 octane...
I do notice some loss of power with 87 but, no ping... :)

I hate you high mileage guys!

Modify and get the N flash... :)

I have lots of free flowing mods to make my 8 breathe easier.

DO a search for my mileage improvement thread, see if any of that helps you out.

You definitely need the N flash. When I got mine, I was getting 13 mpg too, and after the N, I have gotten as much as 19.2 mgp.

If I keep it at 65mph I have on two tanks got 27.5mpg. I allso did a half tank at 55mph and got 29.5mpg. It's very hard to do, you have to stay focused. The Rotary is beging to be reved!

I was driving for 2.5 hours and i was going between 75-90 mph(hit 100 a couple of times :) ) and got 19.8. I dont think i can just cruise at 70 mph the whole way. I would end up falling asleep or something...

This weekend I got my best gas milage
 

I was so excited that I finally broke 300 miles on a tank of gas, I had to take a pic.

22.77 MPG
Shell
93 Octane
Interstate
Cruse @79MPH 90% of the tank

hmm... im getting 14s.. was in 13s before 4000 miles. dunno if its actually going up.

What's the TBS VIN# range for the N Flash? ... Or can all car get it flashed?
I somewhat remember that my VIN built march 04 and didn't fall in the range.

I just got back from a road trip to Atlanta averaging between 75 & 85 mph with A/C on 50% of the time and got 22.5 mpg. I also broke 20,000 miles on this trip. I really wanted to see 300 miles but chickened out at 291 due to distance between gas stations. I still had plenty left as it only took 12.88 gallons to fillerup.

Averaging 18.5 mpg for normal suburban daily driver.

6 MT
M flash
93 Octane Amoco Gold (Always, never anything less since purchased)

My first long trip with P flash.

first off, IMO my 8 is more powerful at low and midrange, as well as from 7000 to 9500.

My highway mileage is a tad lower, but it could be a result of some stop and go driving on the highway...I was getting 23.5, when on my previous trip pulled 26.5

I have not yet been able to do my usual mixed driving with the new flash yet, but I am very happy with the way it is running now. In the past I have not managed anymore than 15.5 with mixed driving...and shifting at 3750 or less hasn't helped. Given the performance increases, I am not so much disturbed by my mileage anymore....and I also think that alot of test drives done by magazines, Car and Driver, etc...should be done again with new flashed cars....I would be curious to see if the 0-60 and 1/4 miles times improved at all.

Lastly, the next time you want to accelerate at WOT, try NOT flooring it. It seems that my car accelerates harder without putting the pedal all the way to the floor. Kinda goes back to the "leading throttle" threads, is WOT really at the floor? The "leading thottle" allows the car to accelerate harder as you lift, so when exactly do we reached WOT, or do we at all?