Again, apparently, a 3-rotor wouldn't pass emissions from what I've read. If anyone can figure out how to otherwise, then that would be neat.

 

Any car can pass emissions if you use a big enough cat. You might need dual stage or something but you can make it work.

-Mr. Wigggles

 

While the low gearing has some impact on MPG, the biggest problem in the wankelmotor is the lack of thermal efficiency: What could be put to work is instead given off as heat.

I'm very, very surprised Mazda hasn't toyed with a ceramic rotor (or a ceramic-coated iron rotor.)

The more heat they can convert to energy, the better. My thinking is that a more heat-resistive material like ceramics would give us not only a fuel efficiency boost, but a power boost as well. Less heat given off, more heat turned into energy.

 

now imagine your doign 70-75 mph and 2.5k rpm in 6th gear. you want to pass so you put your foot down- what happens? at 4k you actually get a little acceleration at 2.5k you wouldnt get any at all. how many people would be happy about that? try it yourself . get on the highway in 6th gear at 2.5k rpm and then stick your foot to the floor.

 

Thermal efficiency is definitely an issue, but is it THE issue? It doesn't seem so. THE issue is related to what made Mazda the successful one and GM (and others) not with rotary development...the combustion chamber. First it was seals...Mazda was successful because of their seal design. Now... you've read the threads on different octane fuels and why one or another is better for an NA rotary. The elongated combustion chamber causes problems with flame front propagation and (nearly) complete combustion. The Renesis is losing fuel economy (and probably power too) to this. Richard Paul has thought of a unique solution using his axial-flow S/C to mix fuel upstream... like carbs and throttlebody injection... but better as it will be even more atomized. This improved pre-mix would be able to burn more completely than the way things are running now. I'd really like to see Mazda give him some money to research this.... because if it works out like he thinks it will... it could be just what Mazda needed to REALLY make the rotary viable.

 

direct injection will fix most of the incomplete combustion issue, which should fix most of the fuel economy issues. The chamber shape issue is kinda tough to work around, but the DI should get the efficiency up quite a bit.

2600lb DI 2rotor Renesis powered RX7

 

It is my understanding that the direct injection engine that Mazda has been working on is a three spark plug per rotor design. This is supposed to improve overall combustion.

This design was also used in the 787B 4 Rotor Engine.

 

I would gladly take that problem. If you want to pass, downshift. I am not sure how you guys drive but when I pass someone I dont mess around. I downshift and get the hell outta dodge.

 

I agree, but I can always drop 2 gears down and find all the power I need. I understand your point, but I’d rather have higher fuel economy than save the (heck not even a sec) downshift.

Yeah, like he said…gosh, have us American’s gotten so lazy? LOL

But again…I understand the slight trade off, but I wonder what a RX8 could get in fuel economy if it was at 2.5K at 75mph? I know cruising at 2.5K gives me my nice fuel economy numbers (for the RX8 that is).

For me:

2.5K @ 50mph (6th gear cruise around town) = 19.5-20 mpg city

Using completely unscientific methods that I know all of you would love to know about, I'd say we would get 26-28mpg.

Remember (as in I-Robot)...my logic is undeniable....lol

 

of course i downshift. but you have to remember that not everyone who drives this car does. every review on record mentions the low torque. i remember C&D specifically mentioning the incredible lack in their passing test. of course they could shift but thats not the point. at least geared the way it is there is a little feeling of push at that speed.

there have been times ( like when my wife was sleeping in the passenger seat), when i have been on one lane mountain roads that split into 2 lanes for an uphill stretch, when i have been quite pleased that all i had to do was drop my foot in 6th and get in the passing lane to go around a whole crowd. with out that the reviews would have been even more horrible and sales would have suffered because of it.

wannahave if you want better mpg then drive at 2.5k instead of 4k

 

I believe modern carmakers are adding heft to all vehicles to offset the difference between the smallest cars and the largest SUV's. So as the SUV's have gotten larger, so have cars.

 

I know, I do in the city but I can't do that on the highway.

OK...then, how about a 7th gear...lol. Dang it Zoom give us answers don't just crush our dreams, lol.

I guess there would be complaints against that but from now on when I hear that comlaint, to then be followed by (The RX8 get's just OK fuel economy) I want the permission to the writer.

While I know it's not really their fault but simply the lack of torque from the rotary.

The reason I think about this is that the 2nd injectors come in at 3.75K right...well, wouldn't it make more sense to Mazda to have it under that change while at 75mph?

Then again...I guess they assume we drive 65 still or even 70. I don't really speed much, but I follow the 5mph plan that keeps tickets away here in FL (per the law).

 

Hi there,

I've been reading posts about what should MY '06 have had and RX8 US sales going down. Everyone believes Mazda should deeply improve the RX8 for MY '07, that's why I started this thread, based on a spanish mag info.

First, I'd like to point out that we, spanish owners, took a really big leap of faith buying our RX8. Spain's motor mags are mainly controlled by germans, therefore any Volkswagen turbodiesel could be considered better than the RX8 by them (Torque, gas mileage, build quality, badge...)

Even the FD, among others (NSX, Mitsubisho GTO, Supra), was not seen as a benchmark, rather than a runner-up against porshe in its time.

I happen to own a subaru impreza gt turbo. You never got that model, there was the 2,5 N/A coupé instead in the US.

That car would go 0-62.5 MPH in 5.45 secs!!! tested!!! it never got the M3 beater title it deserved (For 1/2 the price).

Same thing with the RX8. It IS a fast car, it handles like a dream, it is well put together and has a great engine. I'm not comparing it with german cars, but between the subaru and the mazda... It's up to you to pick up which car of the two is sitting in my garage while the other is being driven.

My point is, the RX8 NEEDS a revamp, the competition is improving and it surely will eventually get it. But, nevertheless it IS an amazing car. It is sporty as well as an everyday user. The feeling I'm getting is that a lot of people here are not comfortable with the car they have. US seems to be torque and drag strip territory. I see a lot of "13 second car, 15 second car..." to me a car is a lot more than 0-400 Meters (Quarter mile)

I guess many people on this forum are die hard rotary enthusiasts. I also would think that many wanted a fourth gen rx7 under the rx8 badge. The 8 will NEVER be a 7, it is different, even if it is upgraded for '07. Improvement or not, I know I have a unique and mindblowing car.

Have a nice weekend and excuse the lecture

 

As a prospective 2007 buyer, I appreciate this thread. With 2 little guys, the practicality of the 8 is rather important to us, but the sporty looks and great handling are especially important to me as a long-time Miata guy. More power would definitely sway me toward the 8--the G35 coupe is my other likely choice--but I hope nothing else changes 'bout the 8, 'cept I'd like a GT w/o the sunroof (assuming this is still not a US option). I am also hoping for direct injection, if that
can really improve both power & fuel economy it's a no brainer. I'd also like to be assured that reliability is still improving.

Looks like I'll be hanging out here more often!

Thanks for the interesting thread!

 

I would, but that's just my opinion--I much prefe the classic curves of the current 8 to the Bangled-esqe creases & angles of the Kabura and so many other contemporary cars.

 

You mean, the RX8 NEEDS a revamp so it can CATCH UP WITH the competition. It needs to have power to match its looks & handling. However, I don't think Ford will let Mazda build a Mustang-killer, so there will be lots of leftover '05 RX8s sitting in dealer's lots at steep discount (just like the 04s went for $8k off the sticker...that's way below invoice), then the same thing for the '06.

How many years of having a car that doesn't sell will the bean counters at Mazda accept before they pull the plug on the whole RX8 program? My prediction is '07 will be the last year for the RX8.

The demise of our beloved car is due to either a lack of Mazda marketing savvy or, as I suggested, the evil ones at Ford are protecting their butt-ugly solid-rear-axle POS Mustang.

 

I'm sorry, but your argument is not logically robust.

The DB9 is $100k more than a Mustang...they are in different segments. No one who is shopping for a DB9 will look at a Mustang & vice versa.

The RX8 & Mustang are in a similar price range and segment, hence competitors for consumer's $$$.

 

You're still wrong. MAYBE... MAYBE Mazda would pull it from the US, but not worldwide. It's worldwide sales have been decent if not good. It's paying its bills. End of story.

No Mustang killer? Dude... Ford hardly sells any Mustangs in Japan and those that are.. particularly the V8 are priced WAY above the RX-8. Like $10k more. The US isn't the only car market in the world, nor the only place that the RX-8 is sold.

 

That's what I'm hoping. Imagine a DI Renesis with an axial-flow S/C...

 

You do know that the RX-8 is sold in markets other than the US, right? The Mustang isn't exactly a worldwide benchmark. And that Ford only only owns a fraction of Mazda? How long before Ford pulls the plug on the Focus-beating Mazda3?

 

You beat me to it, Japan8...

 

sapphonica......what do you mean by faster than the Mustang? 1/4 mile?? If your talking about straight-line speed then Mazda could never make the RX(enter # here) faster than the Mustang (see Shelby GT500 0-60 & 1/4 mile times coming this summer :D) ....unless they make a FI 20b powered car....and even then it would be priced much higher than the Mustang and hence not competition. If your talking about auto-x, the RX8 is already better (faster). They are completely different cars so I assure you that Ford is not worried about the competition between the two. Even though they are priced comparitively, the forces that draw the customer to make a decision one way or the other are very different. On one hand you have a refined GT car that captures the essence of much more expensive 'drivers' cars. On the other hand you have a 'punch in the face' muscle car that makes no appologies for it's existence. I for one am a Mustang person that gave the RX8 a try because of it's great looks. There are others that made a decision to cross over to the 'little rice rocket'....j.k. but as a whole the Mustang owners are different from RX8 owners. Long story short......Ford likes having both and does nothing to hold-back development of the 8 for fear of reduced sales of Mustangs.

 

The NA RX8 is underpowered and undertorqued. Puppy go 'woof'. End of story. Drive an RX8 with FI and you'll know what this car could have been.

Memo to Mazda: bite me

 

By that logic every n/a car is underpowered and undertorqued. Puppy go 'woof. (whatever the hell that means!) End of story. Drive any car with FI and you'll know what it could have been. I've got a friend with a supercharged Viper that can show you how that car could have been but wasn't.

Memo to those who bought the RX-8 who aren't happy with it: Do some research next time! There are other cars on the market you know!

 

Increased Displacement 16B Engine with Direct Injection

More Power (285 HP)

Better Highway Fuel Economy (27 MPG)

Minor trim Changes