I run about 93 octane, and shift at around 5,000 rpm in every gear...unless I'm having fun. During regular driving I average about 18-20 mpg in the city and on highways. It all depends on how you drive. If you redline all the time and are constantly mashing the throttle your going to have poor mpg's, It's just something you have to be ready for. Gas prices arn't cheap.

 

I generally get about 17-18 mpg, though my last tank was 13mpg!!!

 

This is one of the topics that scare me about the RX8.

Disclaimer: YES I know it's a sports car, YES I know mpg is not the main selling point, but NO I will not say mpg does not matter...cause it does...I look at cars as a whole package

I'm new to rx8club.com, but what you guys that have the car need to do is put together your mpg experiences and break it down by type of tranny and miles on the engine (maybe a scale from 1-10 on how aggressive you drive it) and put this topic to REST!!!

I hear so many different things on mpg on the 8 it's crazy.

"I'm getting 12mpg...what's wrong"
"I have no problem, I avg 21 mpg"
"I got 27 highway..."

Gosh, that is too wide a difference to believe it's anything other than the people driving the car that result in those varying numbers. I propose someone makes a spreadsheet and people give some time and effort to helping answer once and for all what the RX8 does FOR REAL.

Just a suggestion...but this is one topic that at times scares me away...

 

Hey now. A bunch of us get crap mileage with out mashing the throttle. I always get around 15.5 mpg and I don't push it. One tank I pushed every now and then for the hell of it (and only to about 7.5K rpm) and I dropped to 14.6mpg or so. Driving about 50% high way I get 17-18 mpg. It's not the driving I don't think. I wish there was a way to take the car in and get the mileage some people are getting. I'd love the mileage you're getting.

The one weird thing is sometimes I think I'm getting good mileage. Like I'll be at 65+ miles and the tank's at 3/4 full (that's 3/4 till the light goes on). Then for the next 1/4 tank I'll travel about 35 miles. Such a let down. I wonder what causes that tho.

 

I get better mpg running 89 octane than 91. On 89 octane I get a solid average of 18.5 mpg (90% city/10% highway). Running 91 octane on the same route the mpg drops to 17 mpg. I used the same brand of gas (Citgo) and I have the 'M' flash.

Also, I have noticed there is considerably more soot on the exhaust tips after running 91 octane compared to 89. ( I clean the tips every night after I California dust the car and clean the brake dust off wheels).

PS, I have never gotten less than 16 mpg (first tank) and have never gotten more than 24 mpg (1 hr all highway run).

 

Ok, here's my bit. Normal "fun" driving get me somewhere between 16-17 mpg while avoiding tickets. I've played around with it lately (12k miles now) and found that if I shift at less than 4k rpm in each gear (yea, I know, no fun), I get 19-20 mpg. My latest road trip, 297 miles, running I-95 at 80-85 most of the time with occasional runs to 110-115, I got 24 mpg. 80 is a little over 4k rpm. I've been told that the two additional injectors open over 4k rpm and that explains the poor mileage most get. The funny thing is that no one passes me when I shift at 4k in every gear. By the time I get to 4th, all are in the mirror. Of course they aren't "racing", but neither am I. So, if you want better mileage, shift at 4k or less and keep the "fun" sprints to a minimum...or just get another "CAR". :D

 

That's what I heard...they said to keep it under 3750rpm when you shift or drive it normal to get the Renesis to give the best mpg.

 

13 mpg here , 1200 miles on car

 

Yep, I am also getting about 13 or less. Best milage was once 210 mi on a tank. Usually it's around 180 mi a tank. It dosn't seem to matter how hard I drive

 

yea me too. averaging mid 13s on my mileage. only have 350 miles on the car though. its gets better as time passes right?

 

Lowest 16.7

Best 18.96

Damn you can't shift this car at under 4k.

Hell you might as well buy an automatic sedan.

It's no fun shifting and going nowhere.

Guess what? I drove my V6 2002 Eclispe the same way and always got 20 to 24 mpg.

 

I have hope it does...from what I hear...

I think we have alot of people that just think that because it rev's to 9000PRM you should be there all the time. If you are running to the redline all the time...I'm sorry but your beating the heck out of that car...you might have fun now, but later you will have a dead 8.

Maybe it's just me, but I would not take a car to redline 50% of the time...daily, in any car...who am I racing? I like driving cars with burst of speed and I love the corners...but not everyday...all the time...poor cars if that's what's happening.

 

You don't know much about rotaries then. There's no reason you can't rev the renensis to 9k rpm on every shift if you really felt like it... keep the oil changed and make sure the motor is up to operating temperature first, there's nothing wrong with it at all. The poor cars are the ones who's owners never rev the hell out of it and end up with carbon buildup and fouled plugs. Hell, even my Miata saw the rev-limiter several times a day and was stronger at 100k than when I bought it.

I need to find for you the video of the two dorks that let their FC rev WOT at redline. That poor thing already had one blown apex seal (which is why they were trying to kill it) and the owner accidentally left the radiator cap off, and still managed to go for almost 10 minutes until the engine baked itself and the exhaust caught fire. Had the engine been healthy and the cooling system worked, it would probably have never died.

 

Best: 24.3 - 100% highway at 70mph constant, AC off, windows up
Worst: 8.2 - 100% "not highway" speeds ranging from 50 to 116 mph for 89 miles... but damn it was fun

 

G8rboy...

I know I don’t, that’s why I read so much here and in other websites…I’m not afraid to say that, there is always more to learn. I want to learn as much as I can and some people are helpful and others…well, not so much. But, correct me if I’m wrong here. So, the way to take care of a rotary is

(1) Watch and change the oil regularly
(2) REV the heck out of it as much as you can (keep it humming at 9000RPM as much as possible) and push it as low as you can in mpg

Note: Sarcasm present above...LOL

This will equal a well cared for rotary engine? I always thought you should make sure the engine warms up, change the oil, and drive it normal. Rev it at times…take it easy at others…don’t do too much of either one. This makes sense too, because race engines do not last too long because of the stress that constant high rpm’s, temp’s, etc do to an engine.

So, just let me know if I’m wrong here…I don’t think I would keep the 8 at 9000RPM’s all the time, it just does not make sense to me.

I just think you’re a rev-a-holic…that’s all…LOL

 

Mine continues to improve, at the beginning 14-15 mpg around town (70% town/30% highway) , 18-19 when 100% highway. Last month @ 12K miles 18-19 mpg around town, and finally hit 22 mpg highway. I got the M flash done, not sure if it is the reason or not, but this weekend with 13K miles on my 8, I took a trip mostly highway to Charlottesville, VA. Keeping it around 3700 rpms on the highway made it to 24 mpg on the way down. On the way back, running harder and at higher speeds still got 23 mpg. And I do like to rev (the 8 has a higher reline than my motorcycle)

 

Side Note:

"Sorry for talking about something else here...but"

The redline for the Renesis is 9000rpm right? I'm asking because I saw a video from Japan and the guy was running the 8 in a track and he let it hit something more like 9,250-9500 most of the time when he changed gears. Was he killing it, or is 9,500 the official redline on this car?

 

No, I never said it was good to bury the tach and keep it there... but it /is/ good to hit redline while accellerating on occasion. What I'm saying is it certainly isn't bad to hit redline if the engine is lubed and up to temp. IIRC Mazda had to release a TSB about a different heat range of spark plugs about a year ago or so for those that didn't rev their 8's enough, as they kept getting fouled. I know many FD guys that followed this as gospel, or ended up with carbon buildup.

 

Keep in mind there's a difference between redline and the rev-limiter. Redline officially starts at 9k, but the limiter doesn't kick in until somewhere in the 9250-9500 range... which is still well below the threshold of damage for the renesis. I believe I've read that Mazda tested the Renesis at 13k RPM for extended durations with no problems... but I don't think the rest of the drivetrain is very safe over 10,500k... not that you would be making much power up there anyway.

 

Steady 15 mpg using Chevron, 16 mpg using Shell V-power with mixed city/hwy. And I shift at 3000 RPMs like 75% of the time. I'm not that keen on wasting gas. Of course the max speed limit of 45 mph around my town doesn't help either...I never have enough room to run the AT to redline with its insanely tall gears.

 

I've had my new 8 for about six weeks now. So far, I'm seeing about 16.5 MPG in all-city driving and about 21.5 with an even mix of city/country/highway driving. I'm not expecting much better or much worse, although I believe 24 MPG is achievable with 95% freeway cruising and fairly reasonable speeds. I'm taking my 8 on a 700 mile round trip over Thanksgiving, so I guess I'll find out.

Anyway, I've decided not to worry about the MPG anymore. The 8 gets what it gets and I'm not going to let that tarnish my overall enjoyment of a very, very fine vehicle. The way I figure it is that I paid $6k to 8K less than the competitor vehicles that are commonly compared to the 8. If the competing vehicles get 5 MPG better than my 8, the owners will save about $250.00 per year in fuel costs based on 10k miles per year at $2.50/gal. At that rate, it will take me 24 to 32 years to use up the slush fund. They way I look at it, I'm way ahead.

1.3L

 

This is one issue that I think is overblown.
My WRX gets 26 miles per gallon on the highway. cruising, 75 miles per hour. But Subaru claims 27! OMGWTFBBQ!!??!?
When I put my foot in the turbo I get 17-18.
GM is advertising their 17/28 MPG V-8's but they don't tell the whole story. If you put your foot into those you are going to get about 10-12 miles per gallon (or less). The 28 miles per gallon is if you shift directly from first to 4th then to 5th or 6th, at crazily low rpms (if they are even attainable, I am slightly skeptical).
The 350Z gets 15 miles per gallon when you put your foot into it.
I think that the rotary is thirsty, and it guzzles a little more gas than it's piston using brethren.
But it isn't something that is so abso-freaking-bad that I want to read about it every day.
I'm done.

 

I see that everyone is experiencing a variety of MPG’s with their RX8. I have had mine now for only a couple of weeks (currently at 500 miles) and I am averaging 12-13 mpg for city driving. I drive at maybe a 5/6 out of 10 as I am still breaking it in. Is this unusually low or does the Rotary engine get better mileage after being broken in?
Btw, I am using 91 octane fuel.

Any ideas would be great if there is a way to increase this or hope for the future. Obviously I did not buy this car for the mpg, but it just feels that I am way below average.

Thanks

 

dragula53,

So stop looking at the threads...why complain, just let people talk about what ever they want to. Sorry, I just don't understand that point of view.

Orbit,

I hope you start seeing better numbers because while I understand:

(1) The 8 is a sports car
(2) Mpg is not it's main selling point

I CARE about fuel consumption. If I wanted Viper fuel economy then you better be giving me 500HP and no less. The 8 weighs 3050 pounds, makes 238HP, and has a small engine...so if you people that get 12-13 are telling the truth (I'm not saying you aint) that would make the 8 a huge fuel economy disappointment. The EPA would have passed along a HUGE LIE to the public. AND, Mazda would not be telling everyone in their advertisements that the Renesis was one of if not the most fuel efficient rotary they have ever made.

My thoughts on this after reading thread after thread (which I appreciate) it's in the driving style and maybe the fuel type...not so much in the RX8. Just my thoughts but I don't own one...so what do I know.

I PRAY, that if I get an 8...I will be able to pull the 18/24 that the EPA listed. Heck, I can pull (with normal driving and a few sprints) 3mpg more in the city from my Probe GT...I think I can pull the 18/24.

 

I would recommend that anyone that gets 13 mpg or worse to complain to the dealer. If the dealer says that nothing is wrong with the car what he really means is that they don't know how to correct the problem.

Continue to bring the car in and establish a record of complaints. If the problem is not corrected then consider the lemon law.

Mileage that bad is a defect. It would seem, from this forum, that most cars are getting about what the EPA numbers would suggest. It is just a few that are defective and this should be corrected under warranty.