Why are Mazda persisting with the Rotary Wankel engine?
Discussion
superman84 said:
Jayho said:
a) who buys a sports car or a sporty car looking for 40+MPG? I'm sorry but someone wanting that would be a mug.
I think the problem with the wankel is that, for all its benefits, sub 20mpg is really poor for "only" 230bhp.Hell, it does 0-60 in 6.1-6.4 and 146mph and revs to 9000. If you want your numbers.
Harji said:
Superman, again you miss the point. Mazda RX-8 is about power and light weight and handling thus having a better power to weight ratio, having 50/50 weight distribution, it is their core philosphy for the RX-8. To many people are obsessed with outputs and not about design and weight and handling.
Hell, it does 0-60 in 6.1-6.4 and 146mph and revs to 9000. If you want your numbers.
I get that and for some some people that trade off suits them. But for me personnally, if I'm burning fossil fuels at the rate of a 350bhp car I would prefer 350 bhp and barrel load of torque. Hell, it does 0-60 in 6.1-6.4 and 146mph and revs to 9000. If you want your numbers.
Also the RX8 isnt that lightweight (1309–1373 kg according to wikipedia).
saaby93 said:
motco said:
Wasn't there a Norton motorcycle with a rotary (wankel) engine in the 1980s?
Yes - what happened to that?I forgot to add
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superman84 said:
I get that and for some some people that trade off suits them. But for me personnally, if I'm burning fossil fuels at the rate of a 350bhp car I would prefer 350 bhp and barrel load of torque.
Also the RX8 isnt that lightweight (1309–1373 kg according to wikipedia).
Have you driven one? For some, outright power is enough, for me driving thorough the country B-roads is far more fun and the RX-8 is one of the best handling cars I have driven for that.Also the RX8 isnt that lightweight (1309–1373 kg according to wikipedia).
The engine is lightweight, as shown earlier, we have seen where it sits to aid the handling characteristics of the car. We have to remember and commend Mazda for this, the RX-8 is a car that was built round the engine. It's all to generic nowadays for other manufacturers , engine sharing, platform sharing, etc etc.
I can't believe how people get so obsessed about headline EU fuel consumption figures for sports cars. Drive a quick car enthusiastically and MPG will be nowhere near the EU figures, except for the RX8.
Drive with a lead foot and you'll perhaps see your 330i do 22mpg, a 350Z 20mpg, an Evo Lancer 17mpg, and the RX8 18-20mpg.
If you do lots of motorway driving and only potter about, fine, the RX8 won't reward your economical driving. But in spirited driving, it really isn't much different to other performance cars.
Drive with a lead foot and you'll perhaps see your 330i do 22mpg, a 350Z 20mpg, an Evo Lancer 17mpg, and the RX8 18-20mpg.
If you do lots of motorway driving and only potter about, fine, the RX8 won't reward your economical driving. But in spirited driving, it really isn't much different to other performance cars.
rhinochopig said:
Must have missed that thread - are you saying that's not the case?
Apologies, I thought you were on that thread!The crux of it was that although the pistons and conrods are being accelerated and decelerated vertically, the relevance of it is limited to engine speed fluctuation and bearing loads as for example when it is 'decelerating' at the bottom of the stroke, it is in fact being decelerated by the crankshaft and thus the force is still being used to drive the vehicle.
No energy is lost in the specific act of accelerating and decelerating the pistons and conrods.
doogz said:
I'm not disputing it, you owned the cars, you know, but do you have a rough idea of the running costs in your ownership, or do you just know the Nissan costs more to fuel?
I don't often fill it up, the wife uses it day to day, but that was based on a recent run to Scotland, comparing what the RX-8's usual fuel consumption would have cost us with what the 350Z's actual fuel consumption did cost us. It obviously depends on the price differential at the particular garage, but the net result is that the 350Z's small fuel consumption advantage is often negated or reversed.The Wookie said:
rhinochopig said:
Must have missed that thread - are you saying that's not the case?
Apologies, I thought you were on that thread!The crux of it was that although the pistons and conrods are being accelerated and decelerated vertically, the relevance of it is limited to engine speed fluctuation and bearing loads as for example when it is 'decelerating' at the bottom of the stroke, it is in fact being decelerated by the crankshaft and thus the force is still being used to drive the vehicle.
No energy is lost in the specific act of accelerating and decelerating the pistons and conrods.
I think someone earlier on mentioned the alternative fuels issue.
Wouldn't be surprised to see a rotary engine running on an alternative fuel (Hydrogen) running directly in series with an electric motor - both comparable in dimension & style, with a clutch/gearbox behind it/RWD etc.
Must be more to it as quite a gap between the RX7 and RX8, it's almost as if Mazda have re-invented the concept.
Wouldn't be surprised to see a rotary engine running on an alternative fuel (Hydrogen) running directly in series with an electric motor - both comparable in dimension & style, with a clutch/gearbox behind it/RWD etc.
Must be more to it as quite a gap between the RX7 and RX8, it's almost as if Mazda have re-invented the concept.
I hate to say it because it always seems like a cop-out but the RX8 is a car you have to live with to understand. I value handling above pretty much everything in a car, if I could have managed with 2 seats I would have got an S2000, I also tested a 330 and WRX and found them both a lot "heavier feeling" and didn't enjoy them so much even though they both felt faster, despite the fact that the WRX isn't.
I enjoy the throttle response and the smoothness the wankel gives, I don't enjoy the fuel consumption but I view it as a compromise that makes the rest of the car possible. As Otolith says, any 4 cylinder is not in the same league for refinement. I like that a car company are still doing something different than just another blown 4. With the regulatory environment (CO2 etc) I can't see a future for any cheap rotary vehicle in Europe at least. Maybe moving up-Market is an option but then badge snobbery becomes even more powerful, as seen in the 3rd gen RX7-it doesn't matter how good the car is if the badge is wrong seemingly.
Whilst there have been reliability concerns a bit of research and preventative maintenance will see you right, my costs are all on my profile and I think they are very reasonable for the type of car it is. The main problem is that by pricing the RX8 as they did an enormous amount of non-enthusiasts were attracted who would (should) be in something like a TT, therefore these jobs weren't done and the consequences are coming through now.
I enjoy the throttle response and the smoothness the wankel gives, I don't enjoy the fuel consumption but I view it as a compromise that makes the rest of the car possible. As Otolith says, any 4 cylinder is not in the same league for refinement. I like that a car company are still doing something different than just another blown 4. With the regulatory environment (CO2 etc) I can't see a future for any cheap rotary vehicle in Europe at least. Maybe moving up-Market is an option but then badge snobbery becomes even more powerful, as seen in the 3rd gen RX7-it doesn't matter how good the car is if the badge is wrong seemingly.
Whilst there have been reliability concerns a bit of research and preventative maintenance will see you right, my costs are all on my profile and I think they are very reasonable for the type of car it is. The main problem is that by pricing the RX8 as they did an enormous amount of non-enthusiasts were attracted who would (should) be in something like a TT, therefore these jobs weren't done and the consequences are coming through now.
rhinochopig said:
Ah with you, but what about frictional and pumping losses though - how do they compare?
No idea, off the top of my head though I'd guess for breathing the Rotary would be worse because it's less efficient and would have to breath more air for a given amount of power, and friction would be better at a given engine speed as it's got less moving parts and performs less revolutions per power stroke.doogz said:
No energy is lost accelerating or decelerating the pistons, rods, etc.
But 2 identical engines, in 2 identical cars, only difference being one is fitted with lighter pistons than the other, it'll be quicker.
Perhaps, but presumably only in the same way that it would be if you fitted a lighter flywheelBut 2 identical engines, in 2 identical cars, only difference being one is fitted with lighter pistons than the other, it'll be quicker.
superman84 said:
J4CKO said:
1300 odd kilos is quite light !
Eqiuvalent Audi or whatever would be 300 kilos more
I think the R3 is close to 1400kg. It's not what I would call a lightweight sports car.Eqiuvalent Audi or whatever would be 300 kilos more
Nissan 350Z - 1525kg
Audi TT 3.2 - 1410kg
BMW Z4 3.0 SE - 1320kg
Mazda RX-8 R3 - 1429kg
So not a lot in it (except with the Nissan). The difference with the RX-8 is it's weight distribution which leads to better handing and that it can seat 4 people. You have to look beyond the figures to get a true picture.
Can only really compare it with cars that will seat four people, the TT will but they have to be small, uncomfortable or devoid of legs, the RX8 always looks quite comfy in the back.
So for me, the real comparisons would be midrange/quicker variations of quality saloons/Coupes like the 3 series, A4, CLK etc.
So for me, the real comparisons would be midrange/quicker variations of quality saloons/Coupes like the 3 series, A4, CLK etc.
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