After 850miles, I've averaged 12.5mpg.

Thats 30% less than the LOWEST level (18-24) stated for the vehicle.

For 12mpg I should be getting a hell of a lot more performance than this.

Total BS. This is just stupid to run around with this kind of gas milage. We need to voice up about this to Mazda and whoever does the estimated gas milage crap on the sticker.

Shifting like an absolute grandma I squeeked out 14mpg ONCE... and that was with a LOT of highway driving.

 

Do a search there is a lot on this subject. I agree but I also noticed mine improve as I put more miles on the car.

 

The more you drive, the better the gas mileage. At least for me that is. I get about 21-23 now. Mostly highway.

 

850 miles? keep track and let us know again in another 1,000. it will improve.

 

if your getting 12 MPG shifting like a granny, I would guess your engine is toast. So far every thread of someone who had an engine replaced had 9, 10 11, 12 MPG.

I get 17 city.

 

How are you calculating your MPG? The reason I ask is because there are some peeps here calculating MPG incorrectly and therefore getting much lower MPG based on a bad calculation. The only guys getting 12 MPG are guys like Syntrix who drive their 8s like Winston Cup cars :p

 

Hey, that's a good point.

Tell us how you calculated mileage. After you do so, then we will pronounce your RX8 toast.

 

More crying......will it ever end?

 

Oh man, that is crazy. Look into the Lemon Laws. Create a fuss. Good luck.

 

Not BS, that's actually quite common during the first 2000 or so miles during break-in. In everyone's experience, it improves as the engine breaks in. It's also been extensively discussed on this forum for months, so it really shouldn't come as any surprise. As for the EPA ("whoever does the estimated..."), their procedures have been extensively documented and discussed in prior threads as well. Time for you to do some homework reading on the forum!

Regards,
Gordon

 

Yo, aaron, I found this post from you the day you bought the car:

Clutch drops and redlining wouldn't have anything to do with your poor gas mileage would it?

 

8_wannabe,

That is a great call. LOL.

 

I was getting 13 mpg in the beginning also....now i get about 15 with 2500 miles on it. It is winter and gas mileage goes down anyway. I will wait to see how the summer is. Also, I hear with the rotary it can take as many as 15,000 miles till you get decent gas mileage....so hang in there. Some may be calculating wrong....my hubby thought he was and brought his Mountaineer in and they told him he was calculating it wrong and he's a smart guy!! Good luck.

 

BTW, I can already tell I get much better gas mileage with 91 octain vs 87.

My first two fill ups with 91 were 17 MPG. then I switched to 87 octain and got 14.5, 15 and 14.5. I'm only at 807 miles, and I filled up with 91 the other day, With my 87 octain when I hit the first large white mark on the gauge I am at 50 miles usually. Whell I am only 3/4's to that mark on the gauge now and i have about 50miles. I'm guessing 18 MPG? I'll know when I fill it up, but it looks like 91 is better gas mileage.

 

Oh....I have been using 89 Octane...mid grade. Did use 91 in the beginning but I did not notice difference in MPG. May try and see now that I have more miles on the car.

 

I tend to disagree with most that mileage goes up as you drive more (if so, the amount is not significant). As some have pointed out, this is mileage given from the EPA and not Mazda. If you drive straight highway, you can reach the the highend (22-23) of EPA mileage. If you drive mostly City, 12-15, seems to be what I have been observing. I have ~9,500 on the odometer.

There seems to be some magic number of miles, that when you reach, your gas mileage will improve significantly. I've been on this board for awhile and this magic number keeps going up... 1,000, 2,000, 5,000, 10,000, 15,000... stop chasing ghosts and enjoy the car..

 

This was my experience as well. I tried 87 after all the talk on the boards that the 8 didn't need high octane gas. My experiment lasted one tankful as I had a noticable drop off in MPG using 87 octance gas.

I got about 19 MPG on my initial tank babying the car and keeping RPMs below 2500 RPMs at all times except when I'd exceed it in 6th gear on the freeway.

Next tank I went with 87 and saw my MPG drop into the 15s. Went back to 92 and my MPG has leveled out in the 17-18 MPG under normal driving conditions. I don't redline my 8, I still haven't done it even once, but I do rev it up to about 7K-8K at least once a day.

My normal shifting points are between 3500 - 4000 RPM.

 

There's only 2 things I've seen that have convinced me they affect mileage. The first is, despite brothervoodoo's contention, when you go over 2000 you get a 1-2 mpg increase. I did, any I recall many others saying so, too. I have seen other alleged increases at 5000, 10000, etc but no one definitely saying it has happened to them, its only speculation.

The other thing is hiway driving. I get a 2-3 mpg improvement with steady (long-distance) hiway driving as compared to local highway/city. There was a thread earlier on statistical analysis, some guy knew how to mathematically combine all the variables and calculate which has true effect. He included mileage on your car, gas type, proportion of city to highway, M/T vs A/T, driving style, etc. etc. He plotted the results and the only thing that really jumped out was the more highway driving you do the better mileage you get. I will add to this, the more hi-rev clutch drops you do, the worse you gas mileage will be.

 

My dad went to the Detroit Auto Show and told the mazda representative that i was getting 15.5 mpg highway and he said that was good! Just rediculous. He gave him a copy of this forum regarding the flooding problem, and of course that was the first time he had heard of it. Some good news, my G35 6M coupe was delivered to the dealership yesterday. Now i just need to get Mazda to take the POS back.

 

My experience is similar to BrotherVoodoo but my city is a little better. Mine has improved a little over time. Gas grade does not seem to have a significant effect on MPG for me. The fuel economy is not much less than older NA 13Bs with almost 100 less horse power. This is a great engine in a great car. But it is what it is. We sacrifice a little economy for the high revs and the incredibly smooth power band of the RX. Nothing compares!

 

I have around 1900 on my Rx-8 right now. I use 91 oct. My commute is around 7 miles one way. With me redlining the car once a day, I get around 18mpg. Best so far was 23mpg on a drive to the coast with several 1-3rd gear 9,000rpm runs. When my car had less than 1k miles on it, I usually got around 14mpg. Slowly but shurley the mpg gallon came up to this point where it has leveled off. CJ

 

read his post. he already said he modified his behavior to "shift like a grandma" and that only resulted in 14mpg.

 

We still haven't gotten an answer from the person that started this thread on how he/she calculates MPG. There are some that are calculating MPT and thinking it is MPG. If you fill up between 200-225 miles you will ALWAYS get a MPT of about 12-13.

 

I did read his post, and I question his definition of "driving like a grandma." I suspect he's incapable of same, realizing that I'm jumping to conclusions. Did he really watch revs and shift points for a full tankful? I dunno; I wasn't there. But I doubt it.

But likewise, read my post where I said statistically it was shown only two factors affected mileage. Going over 2000 miles where many of us saw improvements, and amount of freeway driving. I have not observed, nor do I believe, that driving like grandma helps. I was getting 16.8 mpg, I tried the grandma thing for several tanks, in each case I got 16.8 or within a coupla tenths of that. I gave it up, started having fun again, and still get 16.8. The only time I get better than that is driving over 100 miles on the freeway in light traffic (meaning few speed changes) then I get like 19 mpg. I stand by my comments.

 

"Grandma" means he floors it while sitting 2 inches behind the wheel with his chin almost over the dashboard.