Fuel gauges are not THAT innaccurate....30 miles on 1/4 tank? I've never seen a gauge that far off. 50 miles for the 1st 1/4 tank, 60 miles for the 2nd 1/4 tank, 70 miles on the 3rd 1/4 then about 50 miles until the low - fuel light illuminates; that's the standard way my car's fuel gauge reads. 92 Octane - with 89, add about 20 to the first 1/4, 15 to the 2nd..

 

I'll add my current fuel economy stats:

I have about 1,700 miles on my baby and I've gotten 19.8, 19.4, 18.9, 18.9, 19.2, & 18.7 mpg. Most of my driving is in the city 75% with about 15% highway miles and 10% fun driving. The last tank that came in at 18.7 the fun percentage was more like 35%.

So, considering that I hear these 10-13mpg RX8 owners out there...I'm VERY HAPPY with my fuel economy. Heck...If I drive her easy I can get 19+ without a problem. With some fun I'm still hitting over 18.5.

I hope it lasts...but I really worry that some RX8's have some MAJOR fuel consumption issues or their drivers are beating the heck out of them.

Everyone hitting numbers under 15 should get together and document the problem. Have other people test their cars, take video, etc....prove your story to Mazda or the dealership so they wont say it's YOU that is causeing it.

I was very worried about the stuff I would here on this website about fuel economy but so far after 6 fill ups....those complaints dont' apply. THANK GOD!!!

Good luck to all of you that are going through this!

 

I have 4500 miles on my 8 and I routinely get over 20mpg and I take it to 7k RPM's at least twice a day. I actually am very proud of the gas mileage, I don't even worry about it anymore because it's proven to be a very good vehicle for a narrow focused sports car.

 

I found myself saying the same thing. Then one day, I stopped to think about it, how it is totally insane to convince oneself to be happy to average 20 to 21 MPG hwy. It is somewhat analogous to an illegal organization, such as the Japanese yakuza, rationalizing an honor system for behaving honorably while conducting criminal behavior.

 

I agree...getting 18-19+mpg in a sports car is just fine in my book....I just wish we could use 87 instead of 93 (we don't have 91 in my area).

 

OH...and I mean in the city, not highway. I actually can't wait to take a trip in my 8 to see what it can do in the highway.

18-19+ is great for a sports car in the city....but highway should be well over 20mpg or else that would be a big disapointment.

 

Sounds like you got a good one. I think I got a good one too. But, see again, I can't believe I'm saying that.

 

Here's an interesting write-up on the topic courtesy of MSNBC.COM. Puts our mileage figures in perspective.

By George Lewis
Correspondent
NBC News
Updated: 7:41 p.m. ET March 8, 2005


We've all seen them — those estimated gas mileage numbers posted on new cars. Numbers that turn out to be phony, according to the American Automobile Association (AAA), which has released its own set of numbers for consumers.

"We give them our estimate, our real world estimate, because our auto reviewers aren't very confident in that EPA number," says AAA spokesperson Mantill Williams.

Neither are many motorists.

"It's not accurate on the highway speeds," says one.

"I'm sure they take it downhill with the wind behind you to make it sound good," says another.

There are some huge differences between the EPA mileage estimates and the AAA numbers. For instance, a BMW Z4, rated at 21 miles per gallon city and 29 highway by the EPA gets only 14.5 miles per gallon in the AAA tests.


The popular Chrysler PT Cruiser, also rated at 21 city and 29 highway by the EPA, got a AAA average of 17.5 miles per gallon.

And the GMC Sierra, with an EPA rating of 16 city and 21 highway, got an auto club number of 15.3 miles per gallon.

The problem, says AAA, is that the federal government does not test cars in real world situations and doesn't factor in things like running the air conditioner or driving in stop-and-go traffic. Most tests are conducted in labs with the engines already warmed up, the speed kept below 60 miles an hour.

Now, two members of Congress have introduced legislation to change EPA testing methods.

"They have a statement that says, 'your actual mileage may vary,'" says the bill's co-author Rep. Rush Holt, D-N.J. "They should say, 'your actual mileage bears no relationship to these numbers in the window.'"

The EPA released a printed statement saying it's re-evaluating its fuel economy calculation to provide consumers with more realistic information. The idea: To eliminate that other kind of sticker shock, when you find your new car doesn't measure up to the government's mileage figures.

© 2005 MSNBC Interactive
URL: http://www.msnbc.msn.com/id/7128017/

 

You beat me to it! :D

 

Yeah, I'm very greatful because I think I got a good one too. Keep in mind I have the base 6spd which is lighter (so I'm told) so maybe that is helping out a bit. But...I understand what you are saying...by this day and age we should be getting low 20's in sports cars as the avg.

Go48...Amen to that, thanks for posting! On my sticker window the EPA stated 18/24 for my car but also had a disclaimer that said they observed anything from 15/28 so if 8 drivers are in that range...they really can't complain too much.

 

You're probably having too much fun! My '8 is coming up on 50,000 miles and mpg averages 19.7 with low 14.3 and high 21.1. I've recorded every tankful and almost always drain the tank down to 14.3 to 14.5 gallons. Best mileage is when it's sub 60f ambient, clear traffic, cruise control at 80-85MPH, and NEVER, shift above 2,700, which is way hard to do in this car. Give that a try for a couple tanks and let us know. (Don't think this will work for you, unless you do > 95% freeway driving with trying to stay in 6th when coming up on gridlocks. If you're street'n this car, don't expect too much in the MPG column.)

This is my 4th RX- and I was really looking forward to the Renesis technology delivering more MPG than I had before, which averaged 21-22. Thinking that a mild street port after the warrantee runs out will get me back to what I was getting, before, plus an extra 20-30 hp :D . I still think this car is a great hybrid candidate (yeah, blasphemy, I know). I'd more than exchange an extra 400 lbs for 100 more hp and 100 lb/ft of torque from 0mph all the way up the rev range!

 

Owned two weeks and this is what I get. The mileage sucks.

Mazda RX8
Date Start End Dist Gallons MPG
4-Mar-05 100 238 138 12.33 11.19
10-Mar-05 238 377 139 12.9 10.78

It had better get better. There's not enough power to justify this mpg.
I'm 39, and I drive normally. My 2002 VW GTI got 20 to 25 mpg.

 

Take it to a dealer and show the service people these numbers. It probably isn't going to get much better with time. Driving style can have an impact on fuel mileage, but not to this extent IMO.

 

The car is new to me. Build date 06/03.
the dealer told me that ALL updates, flashes etc had been done.
I expected 15mpg city, 20+ highway.
I just drive normally - breaking the car in right now, so no "racing" is going on.
I'm going to keep documenting it, but I'm afraid I might have purchased a problem child.
This HAS to get better.

 

Just as a note. It was 70 degrees and sunny yesterday and my daughter and I went for a drive in the S2000 - top down of course. Nothing but winding, twisty back roads for close to 200 miles. Driven pretty hard with lots of VTEC action, but not qute as hard as I had been driving by myself. MPG for the day: 26.0 on the nose. Commuting to work and back with lots of stop and go, I get between 21 and 23mpg. Not bad for a 240hp sports car - but it does need premium.

My daily driver right now drinks premium too and only gets 14-15mpg. I was thinking of getting an 8 for the daily grind. These poor numbers everyone posts has me re-thinking that

Dennis

 

Well, folks, I just have to report my personal best for mileage. Just got back from a trip from San Antonio to New Orleans. 10 hours driving, with me (6'4"), my wife (5'7") in the passenger side, and my son (6'1") behind her. No one complained too much. And, for the first time EVER in any automobile I have driven that distance, my back and neck feel great. Used to get very uncomfortable in the RX-7, Nissan Pathfinder, and Isuzu Trooper. Now, to the mileage.

I desperately wanted to exceed my personal best on miles driven on a tank. but unfortunately in both instances where the mileage was great, I was heading into the bayous, where gas is nowhere to be found. I had to fill up with a quarter tank remaining. But holy sh*t, 280 miles and still a quarter tank left? Can't be possible! Anyway, here are the best numbers (worst on the trip was 20mpg).

Miles gallons MPG
280 11.49 24.36
307 13.01 23.57

This was primarily cruising at between 70 and 80MPH on an incredibly boring straight, flat section of highway (I-10). I did use the cruise control more on the first trip than on the way back. Anyway, 24.36 is my best mileage recorded on over 20 years of rotary engine ownership. That being said, I occassionally got 23 in my 2nd gen RX-7 on long road trips, so the 30% improvement the Renesis was supposed to achieve is a bunch of BS. Anyway, I was happy to get what I did, and thought I'd report it.

BTW, I used 89 octane, as I almost always do.

 

My Gas Mileage seems to have gotten much better after I had my car worked on. I had Mazdaspeed lightweight flywheel installed at the dealer and they gave me the new "N" Flash. I don't suppose a lightweight flywheel would help much with MPG so I attribute this increase to MPG to the Flash:



Miles Gallons MPG Date Notes

258-- 13.161-- 19.60-- 06/04/04
199.1-- 12.751-- 15.61-- 09/05/04
204.8-- 13.00-- 15.75-- 09/14/04
190-- 13.00-- 14.61-- 12/08/04
194.6-- 13.312-- 14.61-- 12/18/04
187.6-- 11.622-- 16.141-- 01/06/05
213.7-- 13.294-- 16.07-- 01/13/05
206.8-- 12.919-- 16.00-- 01/17/05
176.6-- 11.761-- 15.015-- 03/05/05

After LightweightFlywheel/body kit/suspension/ "N" Flash

227.8-- 13.114-- 17.37-- 03/10/05 ECU might still be in learning mode
265.3-- 13.276-- 19.98-- 03/19/05


On my last tank you see here it was kinda weird. I only got about 105 miles at the halfway mark on the gas tank, this was with alot of city driving. At the half way point I went cruising on the weekend, I hit about 210 miles at 1/4 tank left to my amazment, but then the last 1/4 tank to empty light I only got about 55 miles out of it. Not sure that our gas meter is all that accurate.

 

Interesting... wondering if you had any Overheating issues w/ long distance driving. I read from other sites how long trips ended up w/ some coolants evaporating.
Wondering if you had any experiences like this, esp. driving in warm/hot weather, or Not. If anyone else has input too, would be great. Thanx.

 

I drove 1177 miles from Washington State to Irvine for Sevenstock7 and had no overheating problems. It was over two days, but we ran at classified speeds part of the time in Cali I remember hitting some MPG's in the low 20's also. My highest was 23+ something that trip.

 

Cool... I plan on taking a 3 day 2,000 mile road trip from the Midwest to Cali in May, when it'll be rather warm.
Anyone else w/ a similar or longer road trip on their Rotary??

 

Just took my first real extended drive. With cruise set at 70 in the flats and no traffic, got 23 mpg. The second tank included 2 trips over "the grapevine" (mountains N. of LA) at (ahem) higher speeds, and also being stuck for a couple of hours in LA traffic. Mileage? 23 mpg. LMAO. This last tank promises to be even better; I've got close to 300 miles and still not quite to the gas light. Might have been some tailwind.

At least it finally lived up to its 24 epa highway rating for me. Around town I usually get 15 or 16.

 

So you guys are getting about 220-230 Miles to a 16 Gallon tank?


Andrew

 

I wonder. Obviously there are physical reasons why the rotary engine gets relatively poor gas mileage when compared to a piston engine (don't ask me to go into detail about this...just know what I've read here and there), but there is a WIDE discrepancy between mpg between different '8 owners.

Some reasons have already been discussed and are still being debated. For instance, I'm not so sure about the "always keep it under 2700 rpm" theory by the guy who is getting 21 mpg max. I tried shifting around 3500-3800 and got a little over 23 mpg on nearly all highway driving on a roadtrip, which INCLUDED 135 out of 230 miles of stop & go highway traffic. Man, that sucked huge.

I wonder how much the following possibly overlooked factors have to do with it? Your thoughts?

* Tires? Are those who are getting 12 mpg using winter tires, and those getting 24mpg using stock (or vice versa, whatever).
* Altitude? Does the '8 perform better in low/high altitudes
* Terrain? Are those of you who are getting great mileage living in the flatlands? (I am)
* Rider weight? How much difference would it make over the course of a tank for the '8 to be pulling a 130lb driver vs. a 230 lb. driver?

 

I think those point are contributors but I cant imagine that they are the reason for the large discrepancy between results. Someone over hear has found that if the throttle is moved more than 20% then the ECU moves into Open loop. If you spend most of your time in open loop then you are going to get bad mileage. So its still possible to rev reasonably high so long as you dont dump the throttle.

Andrew

PS are my calculations correct in my previous post?

 

Not sure where you got those numbers, but most are reporting considerably better mileage than that. My average mileage for the first 3,100 miles is just under 20mpg. So that would equate to 320 miles per tank. Mostly open road driving with maybe 10% what might be considered city driving.

Are you really asking how many miles before the warning light comes on? If that's the question, I typically get 250-270 miles before the light comes on, which equates to about 13.5 gals if you fill up immediately.