The motoring press has been reporting on the new Vision X-Coupé from Mazda, to be unveiled at the Tokyo Motor Show next week.
It is a 503bhp sports saloon with a rotary-electric powertrain that promises up to 500 miles of combined range. It uses a turbocharged two-rotor engine as part of a plug-in hybrid system, and is said to be capable of travelling 100 miles on battery power. The ICE does not (unlike in the MX-30 R-EV) simply act as electric generator - it drives the wheels.
The clever bits are (1) it is designed to run on carbon-neutral fuel, derived from microalgae, which emits 90% less CO2 than a conventional petrol engine. (2) It is fitted with a carbon-capture device at the tailpipe which is takes another 20% off.
So in theory it reduces emissions by 110% - in other words, it's "carbon-negative". Apparently microalgae fuel is also much cheaper and less energy-intensive to produce than synthetic types of alternative fuel. It also has the added benefit of being compatible with existing production engines and fuel station infrastructure, so in theory it could be used from today, once Mazda works out how to produce it cost-effectively at scale.
As you would expect from Mazda, the body shape is eye-catching. It is most definitely not an SUV.
www.autocar.co.uk/car-news/new-cars/503bhp-mazda-rotary-electric-vision-‘carbon-negative’-ice
Last edited by: James Loveless on Wed 29 Oct 25 at 20:48
|
In summary:
- algae are grown, I assume on water, not sure if fresh or salt
- the algae is then processed to make fuel - takes energy
- it is then distributed to fuel stations - takes energy
- the car then burns the fuel - rotary engines historically very low efficiency
- some kind of recovery mechanism captures CO2 - I assume requires energy
A few questions - how much surface area of water is required to grow the algae in sufficient quantities, and what nutrients are required. If grown on fresh water, what impact on potable water resources.
Claims of 110% efficiency sounds like snake oil salesman talk - sceptical.
It is entirely plausible that algae may be a better and more efficient route to green fuels than existing bio-ethanol. Don't lnow how it compares in cost/kwh with solar or wind.
It is likely still better to use fuel to generate electricity centrally to charge batteries through existing transmission lines. Much more efficient than rotary engine losses. Hybrids tend to be more complex and heavier than mono fuel power be it battery or petrol.
Lot of respect for Mazda as a company - but I suspect they are playing a technological catch up for having missed the EV transition.
|
|
The non clever bit is that they have found yet another way to push the rotary engine, again, having failed three times to produce a unit that has longevity.
|
>>It is likely still better to use fuel to generate electricity centrally to charge batteries through existing transmission lines.
Ideally you would generate the electricity from solar cells on your roof, store it in your home battery and recharge your EV at home.
|
|
Better still if your EV IS your home battery. This is already in production (vehicle to home).
Last edited by: smokie on Thu 30 Oct 25 at 09:47
|
Just having a different look at the maths.
Assuming that the fuel is 90% lower in CO2 emissions than regular fossil fuel, but then does the carbon capture kit grab 20% of whats left, rather than an additional 20%?
It still seems an overly complicated way of doing things - why not feed electricity from a grid powered largely by renewables into a battery and use a massively efficient electric motor for zero emissions in use?
|
Mazda - Mazda goes beyond carbon-neutral - Terry
