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Mazda’s rotary engine in the age of the electric car

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Re: Mazda’s rotary engine in the age of the electric car

#181

Post by Supermancho »

14 wrote: post #175
willis936 wrote: post #173

Earlier quoted context omitted.

Reliability is something easily discounted because the data to characterize it is much more difficult to capture than performance data. In most applications you can work around this with redundancies and diverse technologies, but no one makes a fault tolerant powertrain due to cost. I don't think there's a good reason to keep pushing down deadend reliability paths. We should be responding to our hard earned decades o…

Except in Mazdas case the data was there to characterize it. They were notorious for failing very early and suffered bad seals around the rotary shaft. This has been well known for a long time. Many Rx owners knew ride it for 100k miles then sell it before it is too late.

I had an RX-8 for years. It was made in 2007. Someone defaulted on the loan or lost it in a divorce and drove it into a lake, marking it salvage.

I bought it for 25k and was the owner from 2009 to 2019, from 60k to over 150k mi. The maintenance was a bit pricey, due to the fuel injection problems and the electronics would fail in extreme heat of sustained 110+ outside temp (southern california heat) or cold (seattle mornings). I eventually sold it for 9k to a collector. Not a bad deal at all.

Re: Mazda’s rotary engine in the age of the electric car

#182

Post by tom_ »

SeanLuke wrote: post #140

> Despite all this, though, the MX-30 R-EV still falls somewhat short, with a catalog fuel efficiency of 15.4 kilometers per liter (as measured in WLTC mode). With no similar vehicles on the market, like-for-like comparison is not possible, although the Toyota RAV4 plug-in hybrid gets 22.2 km/l, while the Prius plug-in hybrid gets 26.0 km/l. The MX-30 R-EV is clearly inferior in terms of its fuel economy. That's beca…

I wonder how many people drive far enough to regularly need the range extender before they have a chance to plug it in. The fuel economy of this thing is not great if you drive it far enough that it runs out of petrol and you need to fill it up again - but what if you rarely do that? What if you usually drive less than about 50 miles before the next opportunity to recharge it?

Re: Mazda’s rotary engine in the age of the electric car

#183

Post by nogridbag »

Supermancho wrote: post #181
14 wrote: post #175

Earlier quoted context omitted.

Except in Mazdas case the data was there to characterize it. They were notorious for failing very early and suffered bad seals around the rotary shaft. This has been well known for a long time. Many Rx owners knew ride it for 100k miles then sell it before it is too late.

I had an RX-8 for years. It was made in 2007. Someone defaulted on the loan or lost it in a divorce and drove it into a lake, marking it salvage. I bought it for 25k and was the owner from 2009 to 2019, from 60k to over 150k mi. The maintenance was a bit pricey, due to the fuel injection problems and the electronics would fail in extreme heat of sustained 110+ outside temp (southern california heat) or cold (seattle…

Wait you paid 25k for a used/salvage RX-8 in 2009? That sounds crazy. I think I bought one new for around 26k in 2008.

Re: Mazda’s rotary engine in the age of the electric car

#184

Post by jasonwatkinspdx »

kyleee wrote: post #70
userbinator wrote: post #62

Earlier quoted context omitted.

Actually far simpler than a piston engine; the fuel consumption and high production cost was what made them become extinct. https://en.wikipedia.org/wiki/Chrysler_Turbine_Car

Of course Jay Leno has one; not sure if he’s featured it on his youtube channel (I don’t recall seeing it). Awesome

Here's his video on his 1960's one, which is worth watching and some neat animation footage from the period talking about the design: https://www.youtube.com/watch?v=b2A5ijU3Ivs

You can tell Jay genuinely loves cars and the history of the auto world. He's indulging his hobby interest in a way that will preserve these vehicles for future generations to see and learn about. As far as ways rich people can spend their money that's a pretty cool one in my book.

Re: Mazda’s rotary engine in the age of the electric car

#185

Post by jasonwatkinspdx »

jeremymims wrote: post #27
mattmaroon wrote: post #15

I have never understood why the Volt Series Hybrid idea never took off. It is more efficient to turn gasoline into electricity and then drive the car with that than to directly connect the engine to the wheels. Is it perhaps that the cost involved is just too much more than a plugin hybrid to make the small extra fuel savings worth it?

This was how the BMW i3 worked. It was a rather novel design that included an optional small electric scooter motor in the rear that had a 2.5 gallon gas tank. When the battery was low, it would be charged by running the small generator. This was clearly a wonderful idea but it was hamstrung by a silly California rule requiring the gas range to be less than the electric range to qualify for rebates. With a 6 gallon t…

Some friends of mine in the Seattle area had one and absolutely loved it. It was a very practical car for commuting within its range. The extender was barely audible when running.

I think the goofy styling was probably as much of an issue as the tank size.

Re: Mazda’s rotary engine in the age of the electric car

#186

Post by PaulDavisThe1st »

Prcmaker wrote: post #128
porphyra wrote: post #36

Earlier quoted context omitted.

Sports cars, in general, are much loved but seldom bought.

I'm literally waiting for it, have been for quite a while. Small cars have numerous benefits over just being sporty. An electric, or even a hybrid 86/BRZ or miata would be great, but can't be compared to the mini or fiat, and while tesla might be fast, it's huge. Even with a price increase these could be more affordable than a lot of sports cars. The 86/BRZ has been a huge seller too.

I'm not really that interested in cars. We drive a Honda Fit (Jazz for the rest of the world). I was really excited 8+ years ago when Honda said they might do an EV version of the Fit/Jazz - just perfect for my wife and I, combining the great utility of the Fit/Jazz with our preferred power source, all in a reasonable sized and reasonably slick package (incredibly internal visibility also).

Not only has this not happened, Honda have even stopped selling the ICE version of the Fit in the USA. The closest thing to this concept - the Nissan Leaf - has also been discontinued in the N. American marketplace.

Truly pathetic.

Re: Mazda’s rotary engine in the age of the electric car

#187

Post by m463 »

wkat4242 wrote: post #179

One of the cool things about this engine is that it can run on hydrogen with minimal modifications. Not sure if the article mentions this, I don't have time to read it now. But that could make it more interesting when renewable hydrogen becomes common (right now it's not)

Have you looked at hydrogen prices? when the first hydrogen cars came out it was about $17/kg, and I think last time I looked it was around $33. I think that's a LOT more expensive than gasoline per mile.

Re: Mazda’s rotary engine in the age of the electric car

#188

Post by m463 »

It's worth mentioning that serial hybrids, like the BMW i3 rx, might not be able to drive on the freeway on the output of their generator. That's why it's a "range extender" - at some point you have to pull over and charge.

EDIT: this is a big secret that none of the marketing materials (want to) make clear.

I'm uncertain the output of the wankel, but maybe with its power-to-weight it might get closer to being able to drive on gasoline in a self-sufficient way.

Re: Mazda’s rotary engine in the age of the electric car

#189

Post by willis936 »

Retric wrote: post #178
14 wrote: post #175

Earlier quoted context omitted.

Except in Mazdas case the data was there to characterize it. They were notorious for failing very early and suffered bad seals around the rotary shaft. This has been well known for a long time. Many Rx owners knew ride it for 100k miles then sell it before it is too late.

That rate isn’t a deal killer for a plug in hybrid. The engine might see ~1/4th the ware per mile spending the vast majority of its time off. Meanwhile hybrids really want a small and lightweight engine because of all the extra equipment.

Right but then why not use a more efficient and reliable engine? The motors will last hundreds of thousands of miles. The power circuitry should have a similar run if kept cool. Why have an ICE that's more likely to fail with lower thermal efficiency?

The engine used in Toyota's most popular cars runs in Atkinson most of the time with a 40% thermal efficiency.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7425626/

Re: Mazda’s rotary engine in the age of the electric car

#190

Post by bobthepanda »

_yb2s wrote: post #104
user_7832 wrote: post #73

Earlier quoted context omitted.

Apparently they really don't scale well. I found this reddit post explaining it better: > Gas turbines scale extremely poorly. They rely on small clearance between the rotating blades and the housings for efficiency. The smaller the turbine, the greater the relative clearance and the more energy is lost. Gas turbines, at least with established technology, make very little sense below 300ish HP. As a real life compari…

Thank you, I've wondered for years why we didn't have tiny gas turbine engines...

Fun fact, before the oil crisis the French TGV was originally a gas turbine train.
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