Well, here's a pleasant surprise.

After reading in various media (including the buff books, owner's comments posted on websites, etc.) that the RX-8's gas mileage was nothing to rave about, if not just plain bad, I anticipated much of the same for my borrowed car. But, au contraire, this is what I found after one tank:

258.5 miles @ 11.773 gals = 21.957 mpg.

The car, a 6-speed with no body cladding, has just under 5,000 miles on the odo. The driving cycle was moderately aggressive (averaging a 7 on a 1-10 scale) and included highway as well as twisty back-roads routes. A passenger was along for most of the miles, and the a/c was used for brief periods. Ambient temps were around 60 degrees and the elevation was between 300 and 1700 feet.

It should be noted that the EPA figures for the car are 18 and 24, so nothing is out of the realm of reason. But considering the horror stories I'd been hearing, a figure of 22 mpg is very good.

 

16 MPG since I got mine (6MT). 93 octane, normally drive at 6 or 7 on the 0-10 scale. Curiously, my MPG seems to be dropping. I used to get up to 230 miles per ~13 gallon and maybe 240 if I was going downhill on a highway, but recently my light is on around 190 miles, and I've been getting 210 mi per ~13-14 gallons.
I gotta try this V-power stuff or move down to 89 octane.
I'm fully prepared for some schmuck to say "it's a sports car. You want good MPG, go get a Prius" To which I will pre-emptively respond - "Eat me"
And many thanks in advance to the forum member who will monetarily break this down (e.g. it's only another $.xx/mile, $xx.xx/year).

</rant>

Ahhhhh, I feel a little better.

 

I dunno how you people drive the car to get gas mileage like that, the best I've done is a hair under 18. About the same as my old FD.

 

I do pretty well too. Around 18-20 MPG with 70% Highway driving. I wonder why there is such a huge gap all the time? I know I drive and shift at around 4500RPM and still manage to get these numbers, maybe it's how fast I reach the 4500RPM's?

-Rupes

 

I get about 17.5 myself, mixed driving. Better than the 12-13 mpg in some publications that scared away buyers. People don't read the articles and noted it was from constantly shifting at 8k. In other forums that's I read and was a big deterrent.

 

mine seems to hover around 18-19mpg, running 91 octane.

 

Lyn:


Who let you use their RX-8? How come you didn't join us on our Fall Run thats happening tomorrow?

 

For what it's worth I recently had my car in for service. I mentioned my disappointment with the gas mileage the car is getting. Explained what all I had tried - granny shifting, kepping the revs here or there, etc. Anyway when I went to leave the service writer said he had talked to the rotary mechanic about my MPG. I was asked if I use Shell and I replied "always." The rotary mechanic recommended that I switch brands. Didn't have a chance to question it but I thought what the hell. I found it interesting that the rotary mechanic asked specifically about Shell.

So as of now I'm running my 1st tank of Exxon. I decided to try 89 octane to really shake things up. I'm sitting on a half tank and I'm a few miles ahead of where I normally am.

Best I've ever managed was 21 mixed driving. I usually get 15-17 around town.

I don't like hearing the "it's a sports car" excuse either because for 14 yrs I managed to get almost 26 mpg around town with my MR2 turb....unless that isn't considered a sports car.

I love the 8 but man it really $uck$ filling up the tank every four days.

 

I was getting about 18.5mpg with my regualr tires. I put on my Blizzack winter tires and I'm down to about 16.3mpg

 

Hi, Kevin!

Well, it's a press fleet car. (Hmm, that may be the answer: Abuse it from new like it's a rental!)

I'd very much enjoy another M'sters Fall Run, but work commitments require me to abstain from your offer, courteously.

 

I neglected to mention that the tank contained Mobil 89 octane. Plus, I measured the tire pressure for the first time today: 29 all around. That's low, of course, and I'll fix it after an overnight cooling.

Honestly, I am not driving this car in any way differently from how I operate any other. There are plenty of redline runs (even though there seems to be little gained from the practice) but also a fair number of 3-6 and 4-6 short-shifts when entering a highway. No magic formula, in other words.

 

I get a solid 14 MPG in the City (93 Octane, Exxon, Mobil, or Shell)
I got 23 MPG driving to the beach (sustained speed at 85-88 MPH [6th gear over 4,000 rpm] for about 2.5 hours)

From all my monitoring of the milage I've determined that I should just drive the car and put gas in when I need it. I still check the milage when I fill up (14 city, 23 highway...if I go 50?50 I can get about 18-20 MPG). I got sick of worrying about it. I'm probably an 8-9 on the 1-10 scale, and that's how I'm happy driving this car, not worth granny shifting for a couple more MPGs IMO.

 

Yeah i get the same exact MPG (16 MPG) and I drive it 6 on a scale from 1-10.

 

2005, On my third tank, about 70% Highway miles, still in break in period, so no thrashing , yet.

1st, 17.83 MPG
2nd, 18.34 MPG
3rd, 18.81 MPG

 

I wish it was easy to stay away from the 9K redline. I can't seem to do it so my gas light pops on at about 190 - 200 miles. My best was 220 on a tank but that was before the "M" flash...

I've only got 1400 miles so maybe it'll get better ( I don't see how).

 

This is such a weird variance from everyone.
Im an '04 driver w/ 3k miles, still on L flash, am a 10 driver (shift when it beeps, never let the RPM drop below 4000 for power accelerations) and my fuel light pops on at about 220-224 (18-20 mpg).
I have only added 1 quart of oil over about 15 fill ups.

This makes me wonder if apex seal seating is an issue. Any Gen 1 RX-7 guys poking around to provide a historical perspective?

 

21-23 MPG all the time...mostly highway driving.

 

Here's my gas mileage through ~3K miles. Mix of city/hwy. The hump is due to a vacation with all hwy mileage.

otis

 

rx-8 milage while not terrable, IS NOT all that good.
The RX-7's 12b were a heck of a lot better. Got 25-27 on the road at 75 mph
Had Mazda put side ports on a 12b perhalps one would get over 30 highway!, and forget that 238 hp crud.

Just drove my F350 ford truck 2300 mile rt at the speed limits and got 16 m.p.g.
at it has a V10 engine with over 380 HP (heck it get 16 at any speed driven0 -120mph)

 

I just filled up again on my borrowed RX-8 as detailed in the first post. (One correction: I said that the car had around 5k on it when actually it's at 6-ish. Checked the tire pressure as well, to find it had been a little low since I picked up the car. I've corrected it, which now may influence the future readings.)

Cycle #2:

220.0 miles @ 10.888 gals = 20.21 mpg

This go-round contained more stop and go driving than the first, was overall less agressive in nature, no a/c, and was conducted at a near constant 300' elevation as well as 50 degree outside temp.

 

My third, and last, go-round:

197 miles @ 9.214 gals = 21.434 mpg.

Once again, some mixed driving (though with more highway than not), about 50 degrees, and, ahem, correct tire pressure. One other item of possible note: The car's build date was 8/03.

So, my week all told, as well as all-tolled, resulted in this:

676 miles @ 31.875 gals = 21.207 mpg; call it 21. Not bad at all, considering the total package it comes with.

I want one.

 

[QUOTE=speedweasel]This is such a weird variance from everyone.
Im an '04 driver w/ 3k miles, still on L flash, am a 10 driver (shift when it beeps, never let the RPM drop below 4000 for power accelerations) and my fuel light pops on at about 220-224 (18-20 mpg).
I have only added 1 quart of oil over about 15 fill ups.QUOTE]

speedweasel...I'm confused!! 15 fill ups divided by 3k miles = 200 miles approx per tank. 200 miles per tank divided by 15.9 gallon tank = 12.57 MPG!! Not trying to question you...my math may be a bit off!!

I'm in the 16MPG club!!

- Irish

 

My driving is half "highway" - a 30 mile freeway all the way, trip to work in the early morning darkness, cruising pretty much between 70 and 85 mph -- and a return trip home, same 30 miles, in traffic at speeds from zero to 70, mostly near zero. I find that the main variable (in this mixed set of driving conditions) is whether I shift up from 4th or not. It's tempting to leave the car in 4th as there is the most "pep" at cruising speeds in that gear. But, if I discipline myself and scoot it over to 6th, my mileage goes up by about 3 mpg. Probably not too surprising given that the car's moving the same speed in either gear and the engine is turning 30 percent slower - translates to efficiency obviously. Anyway, in the above-described driving conditions, I get about 18 to 18.5 MPG. If I dog it a bit and if I don't bother shifting up, I will see anything from 13.5 to 15; usually closer to 15 MPG. The 18 to 19 or so, works for me.

Oddly enough, I've not noticed anything particularly impressive in 'trip' driving. I might run 20.5 MPG on an open highway trip (in 6th). Once again, I'm happy with that. I didn't buy the car for good-mileage. I bought it for fun; so the 18 or so that I'm getting is plenty good enough....

 

Well at the risk of this topic as being called "beating a dead horse" here goes. Today, I've gotten the best mpg as of owning the car. 26.2 mpg. It was built in June04, AT, no options. Took delivery August 1, 04. No modifications/ flashes, etc. I live in Palm Beach county FL, evacuated to NY for a hurricane, got 24 mpg on Shell 93 for the total round trip. Max speed 94 mph...most often driving around 70. I thought 24mpg was good til today. Drove from Palm Beach to Key West...speed for 100 miles on turnpike was 70/75...speed through the keys for 120 miles was around 45-55. Speed back to Key Largo from Key West was the same....total miles traveled 355...fueled to full topped off, 13.54 gallons. Temp was around 78, average humidity. I was really surprised to have gotten this kind of mpg. I generally average 20 in suburban driving. I'm not sure if it's the Shell 93 or what, but that's all I've been using since purchase of the car. Currently 6k miles on it. Anyway...thought I'd share this. I do notice reduced mpg when I'm driving the car in the shift on the wheel mode.

 

i've had both good and bad mileage out of it. when i take it easy it last longer then when i drive it like i stole it. that's all there is to it. when i shift only after i hear a beep i can see the needle moving. but just today i had to get to the bank to get money to get gas and made it very far before i filled it back up. its all in the way you drive it.