Note: Keep in mind that I do not own a RX-8…yet….

First, we all have to agree that sports cars are historically not the cars to buy to save fuel. HP & MPG just don’t like each other much so we just have to accept that our current and past technology just could not give us a 500HP engine that gets 30MPG in the city. Yet, we can still dream….

I too did not like the EPA numbers on the RX-8 mainly because:

(1) The car weighs only 3050 pounds
(2) The engine is a small 1.3L (I know you can’t really compare a rotary engine to a piston engine)

So my first impression of the rotary was that it was a gas hog considering its size. Furthermore, I compare it to a 2005 C6 vette:

Weight: 3200 pounds
Engine: 6L V-8 400HP

…AND IT GETS 18/28 according to: fueleconomy.org

We have to give it to Chevy, while they normally make ugly cars (Bob Lutz will fix that), they sure do a great job with fuel economy. I mean getting 28MPG in the highway with a 6L V-8 with 400HP is just great! So I felt disappointed with the rotary engines lack of efficiency.

Some people will hate on people who say anything bad about the RX-8 but it’s 2004 and it’s obvious that the rotary engine is simply not very efficient compared to normal engines. We all have the right to complain about fuel economy when, at least for me, “premium” gas is going for about $2.18 per gallon. (I know it’s a high compression engine but I wish they would have made it use regular and lose 3HP or so…then add a supercharger…wink wink) While the difference is truly not a huge hit per month, after a year it hurts a little more, and over the life of the car it becomes significant to the cost of ownership of the car.

Wait, before you hurt your hand writing slurs at me I completely understand that only Mazda has invested in the rotary engine so the rotary is forgiven. I understand that 18/24 for a sports car is not to bad at all. BUT, we forget that gas prices keep going up and it seems that in another 5-10 years we might be crying at the pump…but I believe the 8 will wipe our tears as we drive down the block.

I think, from what I’m learning about the rotary engine, that other car companies should not have punked out on the rotary so early in its life. The rotary was an unwanted child of the auto industry and only Mazda had the courage to invest time and love into the little rotary. I just hope I have enough time on my hands (if we are to believe that we are running out of gas/oil) so we can all see the rotary grow into the perfect engine I think it has the potential to be.

Like I have posted before, I can live with 18/24, but if I drive in the HWY and get only 20 mpg I’ll be one mad customer. Why, because if you sell a car and say it gets 18-24…then it better be TRUE! A car is not an investment…it’s a necessity (now I truly love cars so I see them as a grown ups toy) that consumes our money so at the very least car companies should not mislead their customers with false advertisement. The EPA of course has a big part of the blame. I hear they are going to make some changes with the way they rate cars to make it more realistic.

To conclude, you guys/girls probably toned me out at “First”, I think the main aspect of the RX-8’s fuel economy is more related to the driver than the 18/24 rating it was given by the EPA. It does not make sense that the car can go (after the M flash and some miles on it) from about 15-26 mpg with some drivers in the 20’s while some are in the 15’s…people, it’s how you drive the 8 and not so much the car’s fault.

18/24 Mazda and the EPA say…I’LL TAKE IT!

The RX-8 is such a sweet, comfortable, great handling, practical sports car (yes practical), with enough power (for now…WINK WINK (350HP would be…picture Homer Simpson with a pork chop in front of him)) to leave it’s partner (not driver so much) with a permanent smile on his/her face with every drive.

Personally, I’m looking to fall in love with a car…and with the 8’s curves and performance…she is going to be sweet to play with!!!

G35, your sweet too…but I think the RX-8 gotz you beat…

Note: I hear that Mazda is looking, for the 2006 model year, to either (A) Add a supercharger (B) Add some type of electric turbo type thing or (C) Build a natural 1.6L rotary that makes 300HP and significantly more torque

 

A supercharger? As if the mpg is not bad enough!

 

Gain 50-100HP and lose 1 mpg...I'll take that deal any day!!!

But, I was about to post what would a supercharger/turbo do to fuel economy. I recently heard it would help but have seen in the past that it always hurt fuel economy...

...Im just saying that's all...

 

The problem is there are cars like the Corvette that get similar if not better gas mileage and have much more power. So what is the benifit of the rotary then except for it's smoothness and small size?

 

BUT, I agree that was a thought I had too, if you compare the money and years invested into the piston engines...it makes you wonder why we can't get a 500HP 30MPG city engine.

It's just that the rotary has not been given a chance by anyone other than Mazda.

PS. LOL, I propose a elctro-magnetic rotary engine that uses gravity to help in combustion of garbage while taking care of the kids, walking the pets, and cutting the grass...can it be done...LOL

 

How is tuning affecting the fuel economy in the RX-8? I have not heard much about tuning RX-8's besides it's really hard to do, everything runs through the computer, and there isn't a lot to be gained.

In my current vehicle (Mazdaspeed Protege) we dyno-tuned it with Unichip (piggy back EMS). From the initial tune on the car in stock form we gained 25hp and about 5mpg. I know this is going to be a more drastic difference than in the 8. The Mazdaspeed Protege is turbocharged and came from the factory with super rich mapping.

 

So did the 8 though. Alot of people have seen good gains through tuning with an E-manage I think it was. Seems that leaning out the fuel mixture, and adjusting timing can yield some good gains on the 8 as well.

 

Yea- this might keep me from getting an 8.

 

Dont forget the price of the car! Name some other cars that have all the amenities of the 8, the look, the feel, the PERFORMANCE or the PURE WOW EFFECT it has on other ppl. (and to the person driving it).....now narrow that list to cars at $32K and below....AND can seat four ppl......GOT YA. That is a short list if there ever ws one. I dont think anyone that has an 8 used the sticker fuel rating as a deciding factor for buying it. I know I didn't.

 

Yeah honestly I didn't even look at it until after I signed the papers. And even then I was like "eh whatever."

 

The rotary engine has never been known for being super efficient with fuel by any means. But it shouldn't be as low as some of the numbers I have heard.

What are you guys averaging?

My Turbo II RX-7 use to get 18 mpg on the freeway. That would be watching the boost gauge like a hawk and doing everything I could to keep it out of boost. The engine had 185k on it, but with rebuilt injectors.

 

Marketing...? haha. I know a lot of RX-7 guys who bought an RX-8 when they came out. Take away the "RX" and I don't think those guys would have bought one.


What's the weight dist. of the new Vett anyway?

 

Okay it is 2004. Why is GM still using a old tech push rod engine and stick a Chevy Lumina like steering wheel on the Vett?

 

I havent even checked my gas mileage since I bought it in August, I know its not great BUT, I am not driving it TRYING to save gas. haha. It is to much of a hoot to cut up in it, there is absolutely no way I could drive an entire tank full of gas without playing with it on the road. I didnt buy it to worry about the gas so.....Zoom Zoom. Its the first car I have ever had where I get in the car and then say "Hmm, where can I go now?"

 

:D ok, so I am rambling. lol

 

Dude, go buy the vette, the less 8's on the road the better, besides u have to be COOL not a FOOL to own an 8 !

 

I agree, that is why I got my 8 and I love every mile of it!

Yeah the gas mileage may not be the best but the looks you get driving it, the sound of the rotary, the handling is incredible. It is one awesome car!!!!!!

 

The reason I'm getting an 8 is because of the sports car feel it has, but still having a touch of luxury to it. "Sports cars" suck to daily drive. I want something that's classy, comfortable, and sporty. The RX-8 is all of that. I've also only owned Mazda cars for the past 6 years. :-D

Can I get an amen!?

 

fuel consumption is a single component of the total cost of the car. Remember that the 8 is retail priced very competitively to other cars in its category(s). I've learned how to drive it to get 17/24, and its nice to know I have the option to totally ignore that whatsoever. For me fuel consumption of the 8 is a small price to pay in comparison to the overall value of the car, which most people underestimate.

That said, something like bolt-on (and off) regenerative braking and other efficiency solutions wouldnt hurt at all, either.

 

51:49 f:r, but more importantly the engine is tucked away behind the front axle (kind of like the '8's, actually) so its yaw moment of inertia is fairly low.

In case you were actually serious about this question, the "old tech" LS2 has a much better power to weight ratio most other engines out there, including the Renesis, and still manages to equal an S2000 in gas mileage (and actually outdoes it on the highway by 4-5 mpg). It's also small enough that they can cram it in to the back of the engine back while still having enough clearance to run exhaust pipes and everything else through there. As for the steering wheel, I think that they were more worried about function than form when they popped that one on there.

 

Mazda doesn't perform these tests... so Mazda isn't misleading anyone. If that 24mpg on the highway is so important to you, then the RX-8 really isn't for you (or any sports car). Sure, I can drive my 8 in such a manner to get 24mpg, but why? I might as well by a damn boring-*** Camry and put it on cruise control.

I've never understood why fuel economy is so important to some people when it comes to buying a $30k+ sports car... if your money is so tight you worry about a few mpg per tank, a $15k econobox is probably a better bet.

 

I agree.

In regards to why no one else has worked on rotaries, I've heard that Mazda has patent the Apex seals as these took many years of R&D to perfect. Without these other companies would have to create their own which would not be worth it. Please correct me if I heard wrong.

The rotary may not be efficient in gas compared to a piston engine but it is way more efficient in mechanical design.

 

OK, let me explain some more...

First, I'm planing on buying a "USED" RX-8 because I can not afford a new one. YES, not everyone is rich you know...

I care about MPG because unlike some people...I always go for the best bang for the buck and I take every part of the car into account. Also, unlike some people, I have a family...hopefully a baby soon, and I can't be COMPLETELY SELFISH with my car purchase considering that YES...there are things more important in life, and it pains me to say that...than a car.

Also, as already stated, the RX-8 is a hell of a car for the price. I've looked at the:

GTO
G35

As alternatives to the RX-8 with only the G35 as a serious competitor to the 8. We just have to admit that it's amazing that a FAT GTO (3600 pounds with a V8 with 350 HP) has 29 MPG in the highway. While the RX-8 can barely reach 24 at 1.3L.

But, again...for under 30K the RX-8 is the best buy...

 

Big deal, the 'vette costs 20 grand more than the 8. Even if the 8 averages say, 4 MPG less than the Corvette, it would take an awful long time to spend that $20,000.00 on that little bit of extra gas.

1.3L

 

Hay, I'm only compareing the fuel economy of the engines...that's all. The Vette is WAY out of my price range and has only 2 seats.

Guys, it's OK...the RX-8 a great car and I've only been in it once, but perfect it aint...who cares...no car is...

THE 8 IS GREAT!