Yea....but that can be corrected with a proper design. Wankels are hard to implement which is why Mazda is the lone warrior in this battle. I truly believe if more companies invested in the rotary it could match the comsumption figures of a reciprocating engine.
That is the hollywood version of it anyway. Reciprocating engines are here to stay for much much longer than 30 years. And I don't mean in just a few cars but the overall majority. Right now I doubt the sales of hybrids exceed 1% of total auto sales so in 30 years we might be at around 10-15%. My reasoning is that if you look at the consumption data from the last 30 years you'll notice a dramatic decrease (except for when the catalytic converter was introduced around 82 I think) accompanied by a substantial increase in hp. So in the short term future (say the next 50 years or so) cars are gonna retain the reciprocating engine and consumption will get to insane levels.
Yea...my bad...but obviously I meant consumption will get to insanely LOW levels. I am willing to bet all my donuts that there isn't a single manufacturer out there trying to increase the consumption of their cars
Yea...my bad...but obviously I meant consumption will get to insanely LOW levels. I am willing to bet all my donuts that there isn't a single manufacturer out there trying to increase the consumption of their cars
lol.......yeah.. i just want to make sure i get wut u mean.......otherwise if i reply a post saying that u're insane of saying consumption level will be getting higher...hahaha
wow.. rx7~ man.. tats my dream car~
anywho.. well.. it does have a high fuel consumptions.. DAMMIT~!
if u get that car you gotta be prepare to slap it with tons of money and get your hands dirty.. meh. some buddy of mine owned one.. even thou he loved it but he sold it after couple of monthes.. u know.. $$~
meh.. wish that 06 rx7 woudl come out thou.
and cant wait to see what toyota/lexus comes out wit the new "supra"
Not if they offer the same Renesis engine they are offering in the RX-8. For all it's hype pre-release, journalists were far impressed with the car's handling than the engine. I did an entire project on the wankel engine including the 13B and quite frankly I was expecting more from the Renesis. It's a shame Mazda is the loan manufacturer going after the rotary.....the most efficient power cycle gets no respect
a big part of the cars handling is the engine - it sits very low in the frame and at close to a mid point. And what do jouralists know about rotaries and what exactly was it that didn't impress them? Most of what I have read was positive - this new 13b cranks out 237 HP (not bad for 1.3 litres) - well up from any N/A version from the early 90's.
You put this engine in a 2200 lbs 2 seater (like the 1st gen) and it will go like snot - without a turbo. Mine 1985 is rated at 135 hp and will kill most anything under 200 hp on the road.
No arguments there. What I was expecting though was better fuel mileage and a solution to the oil burning. R&T had an article on the Renesis back in 98 or something and mazda engineers were confident they would address both issues. As for the 237 hp from a 1.3....well I already stressed the wankel was the most efficient power cycle (in terms of displacement to power ratio) so that is to be expected rather than lauded.
No arguments there. What I was expecting though was better fuel mileage and a solution to the oil burning. R&T had an article on the Renesis back in 98 or something and mazda engineers were confident they would address both issues. As for the 237 hp from a 1.3....well I already stressed the wankel was the most efficient power cycle (in terms of displacement to power ratio) so that is to be expected rather than lauded.
Rotaries burn oil in order to lube the apex seals- I'm sure you already know this. The design of the engine makes it difficult to get around this problem - the seals need to be lubed. The only way I know of avoiding this is to premix which is a PITA.
The amount of oil is minimal - maybe a quart every 5K. It is not noticable out the tail pipe and cost is not worth noting.
As for gas milage, as long as these things are reving at 9K all day long, you will burn alot of gas. If you want to putt around, you will actually get good milage - but you will have no fun. Besides that, I don't know any rotary owners that know how to lay off the gas - it's just part of the excitement in driving these cars. The new 13B is much better than the one I have - I get around 14 mpg with 100 less HP than the Renny.
Since you brought up the seals........mazda promised a definite fix to them wearing out quicker. It would be interesting to see how long these new motors last. I ran across few Rx-7s (mostly second gen) that had a good motor past 100K kms. But times have changed and people just wouldn't buy a car that would only last 100K so I do think the Renesis should easily outlast the old 13B.
N/A rotaries last quite a while. There are two guys in my RX-7 club that had 1st gens with over 200K miles on the clock before they had to rebuild the engines. It's the turbo rotaries that kill seals quickly.
Sorry for necromancing but I landed on this topic by chance, don't even remember how I got here. Anyway, there are few tings we need to note about rotaries. First of all the only reason they have been so gas hungry is because the design inherently prevents the fuel from burning completely. This isn't a problem performance wise because you still get a hell of a lot more power per RPM than Otto cycle engines. It does, however, create an emmision control problem because of all of the unburnt fuel sent into the exhaust. In pre-Renesis wankel engines Mazda countered that problem by making the mixture excesively rich and creating a secondary burn in the exhaust to burn off the excess fuel. As you can imagine, it reduced mileage. In the late 70's and 80's the only way Mazda could justify such high consumption was putting the engine in a sports car. Therefore, Mazda never really bothered trying to make the engine thrifty.
With the Renesis Mazda had no choice but to make the wankel engine thriftier. They solved part of the problem by putting two spark plugs. Other than that there's nothing much that can be done to make the engine more efficient. Until we find a metal with a tensile strength that's higher than steel even at high temperatures and that has a friction cooeficient of teflon, we won't be able to increase the compression ratio of the wankel which is the only way we'll make it more efficient.
As for Otto cycle engines they're about as fuel efficient as they can be. There's too much heat loss and gimmicks to power and weight in the vehicle to make them any more efficient. The only way we'll make gasoline and diesel engines more efficient is by using new technologies like the Crower 6 stoke engine, Direct Gasoline Injection, and the Ottawa University Gasoline converter.
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