Rotary is actually a good example for "revolutions" that turned out to be inferior compared to existing solutions. We will see how the new engine will perform in the real world.
Wankel engines work fairly well, but the geometry is so constraining that they can't be improved much. Can't change the shape of the cylinder head. Can't change the valve timing dynamically. That's all fixed by the geometry. They got as good as they were going to get decades ago.
Wankels are cool but they really don't have an advantage over regular engines other than vibrating less as far I know. And they have a few distinct disadvantages.
Better power curves & higher RPM capability, so you can use a smaller, more underpowered engine for the same application.
But that never overcame their mediocre gas mileage (lack of compression/poor combustion chamber shape), oil burning (oil-lubricated apex seals), and need for frequent rebuilds.
The rotaries leaked oil and got terrible mileage, and good luck finding someone to work on them. Other than that, they were zippy. "Usable" they might have been if you keep a low bar, but "practical" they were not.
I've had Mazda's last model of rotary-engined car, the RX-8, as a daily driver for the past five years (sixty thousand miles). It has served me well and my local garage have performed regular servicing and mechanical repairs with no problems.
So I think your opinions are a little bit overcooked.
But I don't want to overdo mine in turn. The fuel consumption is excessive by modern standards (but comparable to other vehicles of similar performance). The engine consumes oil by design and needs to be topped up every few weeks. The whole car is in a high state of tuning, and has given me a few large service/repair bills - but never stranded me at the roadside. My garage once admitted incomprehension and sent me to the main dealer for diagnostics before they could begin repairs.
All in all I think Mazda pitched the RX-8 well as a sporty car for enthusiasts, whose reliability might have come in under par in the market for, say, small family cars. I just want to fight the impression that having a rotary-engined car is a drastically different, worse, experience than one with a piston engine. Generally you just get in and drive.
Wankel engines are just one of (surprisingly many) technologies that were more-or-less viable but just not able to become dominant. Like, we would all still manage to drive around if the only technologies developed happened to be opposed-piston engines, or two-stroke diesels, or axial-cylinder engines with a swashplate. We might even see a few of them come back if the market moves towards series-hybrid vehicle setups. A light little rotary always running at its peak-efficiency speed might be a reasonable choice for a range-extender/series hybrid.
Rotary engines do not "leak oil", they burn oil a modest amount of oil by design. If you think about it, there really wasn't another way to lubricate them.
Practicality was pretty low, though, as you rightly point out.
Rotary engines do not "leak oil", they burn oil a modest amount of oil by design.
I was thinking of the seals, which by about 50K seemed to be a common failure point. But, yes, they did burn a bit by design; no argument there. OTOH, a lot of Wankel defenders in this thread mention RX-8s. I'm remembering RX-7s, and the economy cars that used the Wankels. Those economy cars of the 70s are where the Wankel reputation for poor fuel mileage comes from. Cute TV commercials ("piston engine goes 'boing, boing, boing', Mazda engine goes 'hmmmmm'"), not really the best engine choice to go up against Honda and Toyota at the time.
Little known fact is also that conventional piston gasoline engines are also expected to burn an amount of oil by design, particularly if given a hard usage.
It's always nice to be home in Prague from Munich in 2.5 instead of 4.5 hours in exchange for just 1.5l/100km more consumption (and going 250 (155 miles per hour) instead of 130 km/h).
Isn't there an 130 kmh speed limit on Czech highways? I wouldn't trade two hours of my life for being killed and potentially killing others in a car accident. I also quite understand that Germany has highways without a speed limit, considering that 40% of their GDP comes out of the automotive sector.
We have the big and beautiful 280 between Mountain View and San Francisco, and I thank goodness every time I make my way to the city for it. I'd never go the speeds on my bike I do on 280 anywhere else, but it's just such a gosh darn huge road I get to make a 45-60 minute trip in like 30 minutes.
Huh? My rotary doesn't leak oil. Mileage is an issue but not significantly worse than other sports cars of that era or even today.
I also could probably connect you with a good rotary mechanic (or several) in all 50 states plus Puerto Rico (hell, especially Puerto Rico)
The biggest issue with the FCs isn't the engine, it's the reliability of the electric systems and heat (as a distant second). With the FDs it pretty much the twin turbos. And with early RX-8s (04-early09) it's a lack of proper engine lubrication due to a design flaw.
Did they get the rotary to be usable? I thought even at its best, it was finicky and temperamental. I have never owned or driven one, just doing some idle reading online, so asking this as a serious question.
Lots of torque, lots of pep, though from what I heard, the US version (mine) had substantial increases in pollution controls which hobbled the car. Always first off the line when I wanted to be.
Yes, it burned oil by design. I'd add a half-quart of non synthetic 5W-20 maybe every 1000 miles. The rear bumper required additional car washes, as it'd get a black film, no doubt from cold starts. That wasn't much of a problem.
The big issue it had was flooding the engine. To trigger the condition, turn on engine, let it run for less than 1 minute, and turn it off (like pulling it in or out of a garage). Unless you floored it in neutral before shutting it off, the car would end up near-bricked.
The fix was to have it towed to the dealer where they'd clean out the engine for a few hundred dollars. Later I learned you could tow-start it if you could get it up past 20mph. It'd put all kinds of foul smoke out the back when you did that but in terms of hassle, it was much better.
The car had a POS OEM fuel pump under the rear seat. On hot days you'd get a vapor lock. Not the rotary's fault. Took years to find that problem, and didn't get very long with the fixed version before the stork came and the rotary had to leave.
> The fix was to have it towed to the dealer where they'd clean out the engine for a few hundred dollars. Later I learned you could tow-start it if you could get it up past 20mph. It'd put all kinds of foul smoke out the back when you did that but in terms of hassle, it was much better.
You don't need to do all that. You can just pull the EGI INJ & EGI COMP fuse, crank it for a few seconds, replace and start it up. Many folks put a bypass switch inside the car so they don't have to get out and do it. Works great.
On the RX8 at least, if you hold the gas pedal to the floor while cranking, it disables the fuel injectors. No need to pull fuses.
* Foot to floor, crank for 10 sec,
* let it rest for 30 sec to cool off the starter,
* foot to floor and start to crank, pull your foot off the gas pedal.
Mazda sort of assumed their drivers would read the manual and drive the car properly. I think this workaround was figured out at some point in the 90s anyway.
First off, I agree that the backseat was exceptionally roomy for a 4-door coupe. For adults.
Once you have your first, you realize very quickly that babies come with a LOT of stuff. The first carrier for newborns sticks out a LOT from the back of the seat. The sorcerers at Mazda Engineering made it comfortable for tall people in the backseat by compensating for limited front-back space by using up-down space. This made it impossible for use for an infant unless the front seat was scooted all the way up.
But then there's the stroller. Good luck with that in the comically small trunk opening. Bags of stuff, boxes of stuff, yes, these things are non-optional, and they don't fit in that car, especially all at once.
The final nail was the fact that it's kinda hard to insert a child plus carrier into the backseat with your hands full. Having it back there would've been easy. Getting it back there wouldn't have been. Retrieving it, even more difficult.
After you make your peace with the above, and still manage to cram everything in, bear in mind you still need two adults, not just the driver, to fit in the car at the same time.
We could've done it, somehow, but it was smarter to sell it and buy a cheap used SUV, with plenty of room for everything. It also bears mention that I had used that car as a daily driver for 10 years.
You should have held out on the wait-and-see. The moderate-sized rear cabin with those little suicide doors (you are talking about the RX-8, aren't you?) is absolutely great for baby and child seats.
Also, yeah, I had my RX-8 tow started once. The recovery guy actually suggested I drive his truck while he sat in the car and tried to start it. So there I was with the new experience of driving an enormous full-size recovery vehicle, getting quite concerned as I looked in the mirror and saw clouds of white smoke pouring out of my car's exhaust! But, once properly wary of flooding, the car didn't give me any trouble before or since.
I have an 8 (and am involved in sports car things as a hobby) and I find the back seats to be superior to almost all sports cars and most mid-sized normal cars for seating adults.
More or less usable. They did have a tendency to blow apex seals after 80k miles, which was could end up as a full rebuild of the engine. As far as how finicky a rotary can be, the biggest thing to do is let them warm up before driving, and let them cool right down after you're done. They were never an engine to replace the standard fourbanger, but they weren't any more finicky than say a BMW or Audi at the time of the RX-8
weren't any more finicky than say a BMW or Audi at the time of the RX-8
YMMV, but my E46 BMW has been very reliable compared to an RX-8 bought at the same time. Audi was still in the process of applying the lessons of the RS4 to their everyday cars, but I still wouldn't call the RX-8 reliable compared to its peers. As you hinted, there are a couple of problems that lead to full rebuilds before 150k miles.
Mazda shot themselves in the foot reliability-wise with the first generation RX-8 because they:
* Underspec'd the ignition coils
* Didn't do enough on-road reliability testing
* Lowered the oil pressure and removed OMP ports
* Designed the oil filler breather in a way that allowed oil into the intake
In '04, the first wave of RX8s were coming in to the dealerships after 30k with severe misfire from the coils going bad. Mazda didn't have this failure mode in their factory service manual, so the cars got replacement engines (poorly reman'd in Mexico, not made on the Mazda Japan line). These didn't last because of poor manufacturing. Once the coil issue was figured out, the 8 became much more predictable and reliable.
As noted by Busterarm, they fully got their act together with the series 2 update.
Heh. I mean an engine rebuild at 80k seems kind of crazy. I am both continually amazed at the ICE and at the same time can't wait for it to die out. It's such an archaic technology. Hell, a turbine engine would be so much more fun to have in a car!
It was not, in the end, a production car, but there was a lot of data gathered as to performance and reliability in real-world settings.
Not too long ago, Jaguar had a concept CX-75, which was a hybrid mid-engined supercar where the piston engine was replaced with two Bladon Jets micro gas turbines. After 2008, they didn't want to commit to an expensive limited production vehicle, too bad.
Damn. That sounds like they almost made it work. I wonder how those cars would have done with corn ethanol. Electric boost for initial acceleration and better heat exchangers would have probably completely eliminated the remaining problems with them. Thanks for the link!
Turbos are definitely taking hold in the American auto industry as well, with stuff like the Chevy Sonic and Fiesta/Focus really making good use of them with tiny engines. The 2015 Focus had an option for a 1L, 3 cylinder engine with a turbo for commuters. Great stuff.
The rotary was never invented by Mazda, it was invented in germany and applied first by NSU.
Then it was licensed to many manufacturers, among which there was Mercedes-Benz, which was the manufacturer who got solved first the apex seal problem, and in the late 70s with the C111 prototype car, the first manufacturer to create a side port wankel engine (which mazda would only show on the RX8 decades later) and a 4-rotor engine (which mazda would only show on the 787 racing car in 1991.
Then MB ditched the wankel engine because of low fuel efficience, something that ultimately led to mazda doing the same... in the 2000s.
Compression ignition is more an evolution than a revolution -- it's an iterative improvement on an existing technology.
Skyactiv exists in the first place because Mazda does not have the money or engineering resources to build a hybrid or electric car by themselves. I suspect that in a decade or two, Mazda's decision not to start building hybrids and electric cars when the other major brands were doing so will be regarded as a serious mistake.
investing in high efficiency gasoline engines is a much better bet. the world will be running on gasoline for decades at least. even if europe (doubtful) or US (very doubtful) pull out of gasoline there will still be billions of potential customers around the world.