I got 24.9mpg with every seat in my car full, and the trunk full, cruising on I-84 at about 65-75.

I also thought I heard the secondary ports open at a certain rpm, so I was trying to stay under that, but I couldnt remember what that was, so I said oh well. I think I tried to stay cruising at 3400rpm or so.

 

i average 210-220 when the light JUST comes on

 

I am leaning towards the Houston area changing the gas mix due to Hurricane Ike. I can't say for sure that they have removed or reduced the ethanol, but my wife is also getting better mpg in her Surburban (not as much of a striking difference as with the rx8 though).

How much of an effect will running the AC and not running the AC have?

 

I haven't noticed much difference with mine whether the AC is on or not (I live in FL).

Reading up on Ethanol uses, to increase your MPG, the ethanol content of the gas would have to be reduced.

 

I saw a myth buster on this one. At freeway crusing speed it uses the same amount of gas. I'm not sure about city miles though.

Take care,

Brian

 

I think the ethanol is the most likely change. Since Houston is a major metro area with bad smog, they put around 10% into our mix. If they could not get the ethanol to add to the mix (ethanol can't go through pipelines, and must be trucked in) I could just be getting a more efficient mix of gas.

Add in the lower temps, and less AC could account for the difference. I know if we run E85 (85% ethanol) in the surburban it gets horrible mpg, but e85 costs less.

 

depends on how you figure it out.. dont get me wrong.. i have done 350 miles on a tank. but it was empty, very empty.. btw, you can get more than 15.9 gal into the tank.

not good for the fuel pump though..

beers

 

i get 12MPG. all city driving...but that's ok, i dont drive all that much

 

I can't seem to find the right [bbcode] to format this into a table, but anyways...

date days miles gallons tank% $/gal fillup mpg m/d $/m
6/27 - 282.6 14.260 89.7% $4.419 $63.01 19.818 - $0.22
7/7 10 273.2 14.032 88.3% $4.419 $62.01 19.470 27.32 $0.23
7/18 11 282.3 14.044 88.3% $4.379 $61.50 20.101 25.66 $0.22
7/27 9 264.0 13.964 87.8% $4.299 $60.03 18.906 29.33 $0.23
8/5 9 285.4 13.662 85.9% $4.099 $56.00 20.890 31.71 $0.20
8/15 10 276.1 14.450 90.9% $3.949 $57.06 19.107 27.61 $0.21
8/18 3 321.6 14.479 97.1% $4.179 $60.51 22.211 107.20 $0.19
8/21 3 324.0 14.513 91.3% $3.859 $56.01 22.325 108.00 $0.17
8/29 8 299.9 14.474 91.0% $3.869 $56.00 20.720 37.49 $0.19
9/10 12 298.2 14.890 93.6% $3.829 $57.01 20.027 24.85 $0.19
9/17 7 282.5 14.376 90.4% $3.949 $56.77 19.651 40.36 $0.20
9/27 10 284.3 15.123 95.1% $3.769 $57.00 18.799 28.43 $0.20
10/8 11 271.1 13.843 87.1% $3.469 $48.02 19.584 24.65 $0.18
10/13 5 280.5 15.007 94.4% $3.199 $48.01 18.691 56.10 $0.17

I've been writing the miles from the trip odometer on top of each reciept for a while, so its not hard to compile a table like this in Excell.

 

driving style and % highway vs. city driving?

 

I drive with the cruise control and aside from my 1 redline a day, I tend to keep it at the speed limit... I'm not interested in getting any more tickets.

City/highway time depends on the weeks; on Aug 18 and 21 I did a lot of highway driving and the miles per day are unusually high (which would be easier to see if the table were formatted better)... I think the most important column is price per mile.

Interesting to see the price per gallon of 93 octane has dropped over $1.20 as well...

 

That is all true. All these special "rotary hacks" are just sillyness. Nothing special about "good mpg" when they are driving 30 miles to work. Nothing bad about "bad mpg" when they are driving 4 miles to work. Guess who is eating more gas? That's right, all the "good mpg" people are using up more gas than the "14 mpg" people who only drive 4 miles to work.

 

Is that highway? I get about 200 if I do nothing but city driving, but highway I always get at least 290

 

I don't know how any of you do it.. I get a consistent 220 miles out of my tank (light is on at 200). That is pretty much 70/30 (highway/city). Highest I've ever pulled off was a 250.

 

at what rpm do you normally shift?

 

I actually get a consistent average of 250 miles till the light turns on...and thats city driving.

 

based on your profile of NYC, highway miles aren't really going to be true highway miles. if you had a chance to really stretch the legs out and take a long drive (95 in NY/NJ don't count since there's always traffic), set cruise control, and drive at a reasonable speed i am sure yours would tip closer to 300.

 

Ok guys. Reading through this thread, all of you are doing much better than I. I bought an 04 RX8 with 44k on it. Ive had very low mpg and I cant figure out why. I filled up a couple days ago and reset my trip meter to calculate my mpg. Well, I have driven 56.2 miles and Im on half a tank. WTF Even if I was driving like a bat out of hell this shouldnt be happening. I have change the spark plugs, spark plug wires and battery. Everything else is stock as far as I know. I have also reset the ECU and no luck. Any suggestions on what I should look at/replace. There are no leaks and no funny smells, already had it on a lift. Please help!!!!!

 

and you live where?

beers

 

I live in Somerville, MA just outside of Boston. I travel to and from work and use it for everyday driving. What could cause this?

 

MPG update: two tanks of gas got great gas mileage 250-260ish. This next tank is right back to where it was before (210 a tank) The weather is cooler, and nut behind the wheel has not changed, neither has the driving mix.

Either the gas mix is changing, or this car just has random mpg. Oh well, I bought it because of how it handles, and it still does that no matter what the mpg, so I am happy!

 

Every car is different, but my sweet spot is 81 mph in 6th gear. Can't explain it, some of us have theorized it has something to do with the motor leaning out just enough at that speed. Oh yeah, and I just pulled another 330 mile tank out this past weekend.

 

^330 till the light, or till the gauge is far below "E"?

For half a dozen tankfuls after getting the latest flash my mileage has not gone up at all versus before. Light is coming on anywhere between 250 and 260. It's disappointing knowing that with the winter blends it may be coming on around 230.

 

Until the gauge is 1 tick away from empty.