So... I've been doing alotta research on this, and this is what I came down with.
Feel free to disagree and leave comments.

04 models tend to get low mpg
rx8 tends to get better mpg with age (mileage)
driving in mid rpm (3000~5000) gets better mpg than low rpm (1000~3000)

This one, I'm not sure
adding acetone to fuel gives better performance and mpg
(not that I've ever done it b4)

I know for a fact that cold air intake and K&N air filter gives better performance mpg.

Again, feel free to comment.

After great consideration, I figured out the best way to save gas with the 8 is to stop driving it to work and use this instead.
http://isomerica.net/%7Efluffy/photos/rice/goped.jpg

Worrying about Gas mileage on the 8 is like re-arranging the deck chairs on the Titanic.

it's the same as any other car.

Don't idle
no quick stops or accelerations
don't put unnecessary weight in the car
etc...

On the RX8? Simple, engine swap.

LSx FTW

I know for a fact that cold air intake and K&N air filter gives better performance mpg.


Are you sure about that...

Are you sure about that...
Yea, I'm sure. Although it may be a very slight increase, scientifically it is proven to help with mpg and performance.

If you drive an 8 in such a way as to get the best gas mileage possible, you'll save a small amount on gas and you'll lose the benefits of driving a performance car and possibly kill the engine in the process. Doesn't sound like a good trade-off to me.

Acetone in the gas tank? It may give a boost, but I don't think I want to experiment and see what that does to an 8 over time, but if you go for it let us know.

Owning an 8 means buying a lot of gas, that's how the car is. If gas consumption is really a burden, the best solutions are to either cut out unnecessary driving or get a cheap old eco-box for the daily commute. The rotary needs to spin up and burn a lot of gas, that's life with a rotary engine.

Well you're wrong. Sorry.

How to get best MPG? Easy. Trade the 8 in for a Honda Civic.

Push the damn CAR ..................

i don't understand the how pushing more rpms will increase mpg.

best mpg is best speed to rpm ratio.

go as fast as you can, as close to 800 rpms (idle)

Worrying about Gas mileage on the 8 is like re-arranging the deck chairs on the Titanic.

Quoted for posterity! :)

Install pedals.

So... I've been doing alotta research on this, and this is what I came down with.
Feel free to disagree and leave comments.

04 models tend to get low mpg
rx8 tends to get better mpg with age (mileage)
driving in mid rpm (3000~5000) gets better mpg than low rpm (1000~3000)

This one, I'm not sure
adding acetone to fuel gives better performance and mpg
(not that I've ever done it b4)

I know for a fact that cold air intake and K&N air filter gives better performance mpg.

Again, feel free to comment.

1. 04 models tend to get low mpg. How did you arrive at that conclusion? Same engine.
2. rx8 tends to get better mpg with age (mileage).. Yep my 8 runs better and gets better fuel economy with 66k mi. on the odometer.

3. adding acetone to fuel gives better performance and mpg.
(not that I've ever done it b4). Can't comment. Not me though.
4. I know for a fact that cold air intake and K&N air filter gives better performance mpg. Agree. For a number of reasons.

I was simply trying to put a reason to the difference between people who get
15-16mpg and 18~23mpg
It just seemed like such a huge difference. You don't get this big gap in any other car. I guess it's the complexities of rotary engine.
I was reading numerous posts, and all the people who were complaining 15-16mpg had two similar things.
They owned a 04, and they had low mileage.
I would love corrections on my assumptions, please comment.

PS
And no, I would not trade rx8 for anything else. I love the rotary.

i don't understand the how pushing more rpms will increase mpg.

best mpg is best speed to rpm ratio.

go as fast as you can, as close to 800 rpms (idle)

I think he means turn turn off the engine, put it in neutral, get out and push the car.

Keeping the RPMs as low as possible with a rotary engine is a really, really bad idea IMHO, plus you'll be the slowest thing on the road. If you're that desperate to save on gas, you need a different car.

I was simply trying to put a reason to the difference between people who get
15-16mpg and 18~23mpg
It just seemed like such a huge difference. You don't get this big gap in any other car. I guess it's the complexities of rotary engine.
I was reading numerous posts, and all the people who were complaining 15-16mpg had two similar things.
They owned a 04, and they had low mileage.
I would love corrections on my assumptions, please comment.

PS
And no, I would not trade rx8 for anything else. I love the rotary.

People who get 18-23 do extensive highway driving and/or have a cobb access port with MM's fuel economy map.

People who track their cars get 8-10 :lol2:

I was simply trying to put a reason to the difference between people who get
15-16mpg and 18~23mpg
It just seemed like such a huge difference. You don't get this big gap in any other car. I guess it's the complexities of rotary engine.
I was reading numerous posts, and all the people who were complaining 15-16mpg had two similar things.
They owned a 04, and they had low mileage.
I would love corrections on my assumptions, please comment.

PS
And no, I would not trade rx8 for anything else. I love the rotary.

I suspect that the main reason the gas mileage can vary so much is the wide RPM range that the car can be driven at. If you rev more, you burn more gas.

I think it's more about driving style than differences in the actual cars. I know that the mileage I get with my car can vary a lot depending on how I drive it, and there's a very big difference between city and highway mileage, which points to driving style as a major factor.

I have not gotten a better tank then 15mpg with the occasional 16-17mpg. This is throughout a period of 10,000 miles of ownership in New York City.

^^^
That's about what I get with city driving, often it will be around 13mpg.

Best way to get Smileage;
Drive it like it was meant to be driven.
Redline it once a day
Hit the canyons on a regular basis

this makes you smile more often, therefore smiles per gallon are increased

I simply leave it in park.

I get 18 city 23 highway, just as advertised. I've gotten as high as 25 highway. And I redline at least once a day.

I think a lot of these difference have to do with things like plugs and coils, as well as gas quality. I'd be willing to bet that those getting less than 12 in a non-racing application have old or weakening plugs/coils.

After great consideration, I figured out the best way to save gas with the 8 is to stop driving it to work and use this instead.
http://isomerica.net/%7Efluffy/photos/rice/goped.jpg

Worrying about Gas mileage on the 8 is like re-arranging the deck chairs on the Titanic.


aaaaahahahhahahahahaha :lol:

"I drive my car like an answering machine....shift at the beep" (someone said it before but not exactly sure) I fill up when i'm down to a quarter tank and just drive it and not worry about it some tanks get better some get worse because I drive it harder....you only live once have fun while u can

I agree it's a mix of driving style & keeping the car maintained...(coils, plugs & wires) if you keep up with the maintenance you'll get the same mileage 18/24.5mpg on avg (non-tracking mind you)...just drive the hell out of it!

Why does everyone worry?? I just drive the car how I fell, If i want to redline it, I redline it, If I want to cruse then I crues. If I have to fill up tomorow, then I will fill up tomorow, If I get 10mpg then w/e. Its a proven fact that bitching about MPG will not increase your MPGs

I got 16 mpg no matter how hard i drove it, in a 50/50 mix of city/highway. Put on an AP and got it roughly tuned, and it's up to 17-18. Once I figure out how to datalog with the ap, I'm assuming it'll go even higher.

Get a Hybrid version of the car!

Why does everyone worry?? I just drive the car how I fell, If i want to redline it, I redline it, If I want to cruse then I crues. If I have to fill up tomorow, then I will fill up tomorow, If I get 10mpg then w/e. Its a proven fact that bitching about MPG will not increase your MPGs

I see you have already reached enlightenment. :lol2:

"Enlightenment" that's near Amarillo isn't it?

Mods please close this thread...there are pages and pages of the best way to increase mpg's. As Mugatu would say...SEARCH!

You want the BEST MPG? Here it is:

Make sure your workplace is 200 miles from your home.

You will get THE BEST MPG out of anybody on this forum.

This sounds contradictory, but if you can wrap your mind around this concept: those who get the best mpg, are actually using more gas than those who get less mpg.

Good rx8 mpg is just a sham, and it is time to smash that sillyness with true rotary logic. If your goal is to use less gas every week, you definitely want lower mpg. Lots of these rx8 cats report "I get same crap mpg no matter how I drive". That is true. Guess why? They all live like 5 miles from work, and are using less gas resources than all you 50 mpg freaks driving 800 miles to work.

I think we all understand the difference between city and highway mileage. It's right there on the sticker.

There IS a tried and tested PROVEN way to increase the '8s mileage -

The AP Cobb programmer comes with a few pre-made computer reflashes, one is named 'Economy' and will give you about 10% better mileage, under all conditions.

I tried it for about an hour, and found it HORRIBLE. It takes 90% of the fun out of driving - the car accelerates slower, throttle response is awful, and there is NO punch left in the engine. It only stayed in my car until I could get home and overwrite it.

So it DOES give better mileage, but you'll have to get figures from somebody else!


S

First get the Pogue carburetor installed.

Then fit it with a throttle body spacer and vortex air insert.

Then put ionizing magnets on your fuel line.
You should be good for at least 140 MPG then.


If that isn't enough, you can remove the front and rear windshields to let air pass through and reduce wind resistance.

Me, I just drive the damn car and put gas in it when the light turns on. I took the time to read the window sticker before I bought it.

Worrying about Gas mileage on the 8 is like re-arranging the deck chairs on the Titanic.

the ship is going to sink and we all die anyways?

drive the 8 in GT5 :)
no gas required!

drive the 8 in GT5 :)
no gas required!

You also don't have to pay for damages when you crash going 140+ mph

You also don't have to pay for damages when you crash going 140+ mph

LOL, yeah, you also don't even have to take any damage to your car.

30% increase in gas mileage!

I have recently had a dramatic gas mileage increase. I used to get 14-15 mpg. That has recently increased.

The first (and main) cause was because I had a misfiring coil and wires. They were replaced under warranty. It's like having a whole new engine.

The second issue was tire pressure. Evidently my tires were near the 28 psi mark. I recently refilled up to 35 psi. You can feel the difference between 28 and 35.

On a recent long trip (1300 miles from Dallas to Albuquerque and back), I got 19 mpg all day long, and a solid 20 mpg on the last leg. Last leg was mostly cruise control, 75 mph, roof open, but no A/C. Okay, I did have an 18.5 mpg leg, but I had a few 100+ bursts in eastern N Mex, and some sustained 90 mph time.

Anyone with mpg problems, have your codes pulled for ignition missing, and bump your tires up slightly. Worked wonders for me.

30% increase in gas mileage!

I have recently had a dramatic gas mileage increase. I used to get 14-15 mpg. That has recently increased.

The first (and main) cause was because I had a misfiring coil and wires. They were replaced under warranty. It's like having a whole new engine.
I didn't know you could get coils and wires replaced under warranty. How many miles? Was your only presenting problem poor gas mileage or was the engine running terribly rough?

My complaint to the dealer was rough idle. I am still within my 12/12 warranty.

the ship is going to sink and we all die anyways?

yup. The 8's gastank may have 3 hulls, but it's made from poor quality steel so if you hit an iceberg you're as fucked as a pinto being hit from behind.

I think at about 75-80mph cruising i get the best MPG\

i had fillled up my tank earlier this week and ill let u know how many miles i got to a full one

I think at about 75-80mph cruising i get the best MPG\

i had fillled up my tank earlier this week and ill let u know how many miles i got to a full one

^ +1 I just did a straight 288 mile trip last week at 75-85 mph interstate all the way on 13.431 gal... let's see that's ... yup 21.4 mpg :)

"Enlightenment" that's near Amarillo isn't it?



That's near Amaretto, isn't it? Gimme a glass of that with a few ice cubes and I'll show you fuckers how to drive.

^^^^^ well said well said

I get about a 15% increase in mileage when I premix about 3 oz. of 2 stroke oil.

Best highway mileage I've gotten is using lowest reasonable rpms for slow acceleration and speed control for very steady 65 mph for 26-28 mpg (3x) on a 6-speed manual. Might be better at 55 mph but haven't managed to go that slow. It's terribly boring to drive like that but I was interested in seeing what the upper limit of fuel economy is. IIRC, someone here claimed to get 29 mpg once. It is nearly impossible to fill the gas tank completely and it isn't good for the evaporative system anyway so it's hard and inadvisable to try to get overly exact figures so I think there's at least a 2 mpg margin of error in most measurements.

My complaint to the dealer was rough idle. I am still within my 12/12 warranty.
Thanks, but what is the 12/12 warranty?

Sorry Bro. Still within 12 months and 12,000 miles. If I think a wiper blade is a little flaky, I get it replaced. (For another month and 1/2).

And why is topping off bad for the evap system. Somebody school me on that.

Sorry Bro. Still within 12 months and 12,000 miles. If I think a wiper blade is a little flaky, I get it replaced. (For another month and 1/2).

And why is topping off bad for the evap system. Somebody school me on that.Hmm ... I didn't realize Mazda gives better replacement warranty coverage during the first 12 months.

I'm no expert, but what I've heard about overfilling the gas tank is that if gas (and not just fumes) backs up into the charcoal canister enough times, it can degrade the charcoal, cause it to break up into small bits, which can then lodge in a valve in the evaporative system, causing it to stick open. Not sure of that, just repeating what I've heard from people who at least seem to know more than me.

is nearly impossible to fill the gas tank completely and it isn't good for the evaporative system anyway so it's hard and inadvisable to try to get overly exact figures so I think there's at least a 2 mpg margin of error in most measurements.

I would hope most people simply divide the gallons when they fill up by the miles since they last filled up. If you're dividing by the theoretical capacity of the tank, you're going to be way off. Isn't that how most people do it?

I would hope most people simply divide the gallons when they fill up by the miles since they last filled up. If you're dividing by the theoretical capacity of the tank, you're going to be way off. Isn't that how most people do it?Of course. No one said anything about using the theoretical capacity of the tank. But I'm sure you also realize that simply dividing the gallons when you fill up will also always introduce some error since the tank will not be filled up to exactly the same point each time, hence what I said about a margin of error.

You can easily put more than a gallon of gas into the tank after the first "click" of the gas pump. Your MPGs would then vary wildly. My measurements are done by filling until the gas is visible in the filler, but given that charcoal canister issue, I'm gonna stop doing that.

You get better mileage in the RX8 by driving south, because you are driving downhill.....
Just look on any map.
:lol:

how much can the tank hold at maximum capacity?!?! i know its not 15.9 or whatever it has to be more.

You get better mileage in the RX8 by driving south, because you are driving downhill.....
Just look on any map.
:lol:

Lies! the earth is fatter at the equator. Drive south and you're always heading uphill!

Unless you're in the southern hemisphere.... :lol:

You get the best mileage with an RX-8 by towing it with a Vespa.

how much can the tank hold at maximum capacity?!?! i know its not 15.9 or whatever it has to be more.

I thought it was 60 liters, but I also thought that it was 16.9 gallons. And 60 liters is only 15.9 gallons so IDK

I thought it was 60 liters, but I also thought that it was 16.9 gallons. And 60 liters is only 15.9 gallons so IDK

and is maximum capacity until the nozzle clicks, or filling it some more e.g. till you can see the gasoline almost overflow

I didn't buy my 8 to worry about gas mileage.. longest I've done on 1 tank though was 324 miles with one last little bar before the E.. 100% highway driving in 6th gear at 4k RPMs I believe.

there is a simple answer.. fill up and record the mileage you have.. then at half a tank add another $10 without recording it.. When you tally it all up on paper you'll hit like 30mpg or more.. baller...

anyway in the real world keep it under 4000 use premium good not bp shit or arco.

buy all lightweight parts (flywheel exhaust pulleys) and use the cruise control often..

Good luck gentlemen!