Are Mazda being different for the sake of it?
Discussion
https://www.autocar.co.uk/car-news/new-cars/mazda-...
I generally quite like Mazda being a bit headstrong and going their own way. In my opinion it's worked out OK for them in the past. Take the Skyactiv-G engines and the newer Skyactiv-X engines.
But this? fitting a rotary to what is already quite a poor EV offering. I am not so sure.
Are rotary engines even that good in terms of efficiency and emissions? My understanding was that they weren't! I guess in terms of NVH it'll be smooth and quiet but, I dunno, seems like a waste of effort?
Perhaps they are using this MX-30 platform as a bit of a rolling test bed, see what sticks and ultimately it'll just hit a dead end. But at the speed things are going it feels like they might be trying to find answers to questions that already have been answered.
I generally quite like Mazda being a bit headstrong and going their own way. In my opinion it's worked out OK for them in the past. Take the Skyactiv-G engines and the newer Skyactiv-X engines.
But this? fitting a rotary to what is already quite a poor EV offering. I am not so sure.
Are rotary engines even that good in terms of efficiency and emissions? My understanding was that they weren't! I guess in terms of NVH it'll be smooth and quiet but, I dunno, seems like a waste of effort?
Perhaps they are using this MX-30 platform as a bit of a rolling test bed, see what sticks and ultimately it'll just hit a dead end. But at the speed things are going it feels like they might be trying to find answers to questions that already have been answered.
Edited by Otispunkmeyer on Tuesday 10th January 00:17
Otispunkmeyer said:
Are rotary engines even that good in terms of efficiency and emissions? My understanding was that they weren't! I guess in terms of NVH it'll be smooth and quiet but, I dunno, seems like a waste of effort?
Rotaries can be pretty efficient if they're designed to run at WOT and constant revs (ie as a generator). Their usual issue for cars is that they're inefficient running at low outputs; not really a problem if it's being used as a range extender though. kambites said:
Otispunkmeyer said:
Are rotary engines even that good in terms of efficiency and emissions? My understanding was that they weren't! I guess in terms of NVH it'll be smooth and quiet but, I dunno, seems like a waste of effort?
Rotaries can be pretty efficient if they're designed to run at WOT and constant revs (ie as a generator). Their usual issue for cars is that they're inefficient running at low outputs; not really a problem if it's being used as a range extender though. With respect to the RX-8 we know those cars had a lot of problems and often need to be rebuilt. I would assume they've been able to sort a lot of those issues out and presumably will have strict startup and shut down procedures etc. Or again, does the operation cycle mean a lot of those problems are diminished also?
Otispunkmeyer said:
With respect to the RX-8 we know those cars had a lot of problems and often need to be rebuilt. I would assume they've been able to sort a lot of those issues out and presumably will have strict startup and shut down procedures etc. Or again, does the operation cycle mean a lot of those problems are diminished also?
Good question. The traditional issue with rotaries is that the rotor tips wear; they've got gradually better at that but it was still an issue on the RX8. Without the placement restrictions dictated by having a conventional drive-train layout, I guess it should be possible to design an engine such that the rotor tips are replaceable without removing or dismantling the engine, in which case it's probably a service item like the spark plugs on any other petrol ICE. There were also issues specific to the RX8 with things like flooding on warm-starts but I don't think that was anything inherent to rotary engines. I like Mazda.
they gave us the MX5 obviously.
I have a CX-5 for general duties because it drives far better than most crossovers and I can turn the nannies off, and they stay off! good price, comfortable and reliable. The Skyactive engine also does a fair job for its intended purpose while returning real world 40mpg.
Good on Mazda I'd say.
they gave us the MX5 obviously.
I have a CX-5 for general duties because it drives far better than most crossovers and I can turn the nannies off, and they stay off! good price, comfortable and reliable. The Skyactive engine also does a fair job for its intended purpose while returning real world 40mpg.
Good on Mazda I'd say.
I can believe a rotary engine can be extremely reliable and efficient if it runs at a constant speed and that speed is below the point at which significant wear of the rotor tips occurs. In a traditional cylinder engine isn't the highest period of cylinder wear is when the engine rapidly increases in RPM? If so assume the same is true of a rotary unit - which is a period of wear entirely avoided if the engine is gently brought up to 1200 rpm or whatever and then sits there.
This article makes some good points about why a rotary engine is potentially ideal for the job: https://www.evo.co.uk/mazda/205567/mazda-rotary-en...
The question is, do we need EV's with range extenders? In theory they could be very useful for some places but in practice, this particular car is still only given a range of 250 miles even with the range extender. To me that sounds like compromising the benefits of EV packaging and weight distribution/placement by adding a ICE into the mix which mostly won't even be used, and the end result still doesn't go as far as something like a model 3 LR. Nor as fast..
I can't help but think that one day people will come across range extender EV's in a museum as part of an 'evolution of the car' display and be puzzled that such a thing ever existed.
This article makes some good points about why a rotary engine is potentially ideal for the job: https://www.evo.co.uk/mazda/205567/mazda-rotary-en...
The question is, do we need EV's with range extenders? In theory they could be very useful for some places but in practice, this particular car is still only given a range of 250 miles even with the range extender. To me that sounds like compromising the benefits of EV packaging and weight distribution/placement by adding a ICE into the mix which mostly won't even be used, and the end result still doesn't go as far as something like a model 3 LR. Nor as fast..
I can't help but think that one day people will come across range extender EV's in a museum as part of an 'evolution of the car' display and be puzzled that such a thing ever existed.
TheDeuce said:
I can't help but think that one day people will come across range extender EV's in a museum as part of an 'evolution of the car' display and be puzzled that such a thing ever existed.
I think so too, in the future.but while range anxiety is real (and justified in many cases) a rex is a good transition. surely way better than a complete ICE drivetrain?
CABC said:
I think so too, in the future.
but while range anxiety is real (and justified in many cases) a rex is a good transition. surely way better than a complete ICE drivetrain?
Made sense with the likes of the i3 for me, where it was an addition to the BEV version due to the limitations in battery tech and charging availability at the time due to the car being very early to the market.but while range anxiety is real (and justified in many cases) a rex is a good transition. surely way better than a complete ICE drivetrain?
All it adds now is additional complexity for very little benefit as far as I can tell.
I do have to wonder what is going on with the Japanese firms, they really don't seem very keen on BEV do they and have ceded a huge amount of ground to Korea and Chine in the same way they have in consumer electronics.
This is exactly what a rotary engine is designed for. Light weight, small to package engine. It means the car can have a range of a 60kWh battery car with only 35kWh. Hopefully the heating is also done by the engine meaning that cold temps shouldn’t effect the range too much.
It also won’t weigh 2.5ton.
The rx8 used to return 20mpg driving like a saint or like you stole it.
It also won’t weigh 2.5ton.
The rx8 used to return 20mpg driving like a saint or like you stole it.
You really don't want the heating provided by the engine, or at least not solely by the engine. Otherwise, when running on battery alone (which should be the majority of usage for a range extender car to make sense) you have no heating. It would be daft not to make it possible to circulate the coolant through a cabin heat-exchanger if the engine is running, though.
SWoll said:
I do have to wonder what is going on with the Japanese firms, they really don't seem very keen on BEV do they and have ceded a huge amount of ground to Korea and Chine in the same way they have in consumer electronics.
The Japanese invested heavily in fuel cell car development early on, and of course were there very early with hybrids too. At that time the man on the street generally assumed things that hydrogen made sense as it was comparable to re-fueling a petrol car, and of course back then (we're talking late 90's), everything that ran on batteries was seen as a nuisance. Apart form by certain ladies perhaps... 
But anyway, I can well imagine that when they set the direction of research and investment that the focus groups were all telling them that the public would be far more likely to consider a hydrogen fuel cell car than a battery powered one. Of course a decade or so later Tesla popped up and all of a sudden people started to realise that actually battery cars could be workable for most people, and simpler, and generally quicker.
kambites said:
You really don't want the heating provided by the engine, or at least not solely by the engine. Otherwise, when running on battery alone (which should be the majority of usage for a range extender car to make sense) you have no heating. It would be daft not to make it possible to circulate the coolant through a cabin heat-exchanger if the engine is running, though.
Ive read it as the rotary would always be on charging the battery or am I wrong in thinking that.sam.rog said:
kambites said:
You really don't want the heating provided by the engine, or at least not solely by the engine. Otherwise, when running on battery alone (which should be the majority of usage for a range extender car to make sense) you have no heating. It would be daft not to make it possible to circulate the coolant through a cabin heat-exchanger if the engine is running, though.
Ive read it as the rotary would always be on charging the battery or am I wrong in thinking that.kambites said:
sam.rog said:
kambites said:
You really don't want the heating provided by the engine, or at least not solely by the engine. Otherwise, when running on battery alone (which should be the majority of usage for a range extender car to make sense) you have no heating. It would be daft not to make it possible to circulate the coolant through a cabin heat-exchanger if the engine is running, though.
Ive read it as the rotary would always be on charging the battery or am I wrong in thinking that...Engine purring in the background...
As a lover of the somewhat obscure, this tickled my interest a bit. I had a highly modified RX-7 back in the day. I am, mind you, somewhat bemused that a rotary engine can be efficient as that car drank some serious amount of juice. And oil. And had to be rebuilt of course. But good times were had none the less.
You could imagine that a 30-odd kWh EV could be quite nice to drive, perhaps like an i3. But that doesn’t seem to be the case with the MX-30. But if it had been fundamentally good then I think the rotary engine add-on could have been interesting. Maybe they could put this combo in something competing with the C63 let’s say.
You could imagine that a 30-odd kWh EV could be quite nice to drive, perhaps like an i3. But that doesn’t seem to be the case with the MX-30. But if it had been fundamentally good then I think the rotary engine add-on could have been interesting. Maybe they could put this combo in something competing with the C63 let’s say.
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