On 16Jul2019 1039, Ethan McKinney wrote:
> My MIL bought a Mazda with a Wankel as well. The problem was that no
> one but Mazda dealers knew how to service it, and the same with parts
> (although this is more common).
>
> The Wankels were actually highly reliable as long as the apex (tip)
> seals didn't blow, so it's generally worthwhile to change them on a
> schedule well shorter than their expected life. Wankels are also
> stunningly tiny--if you've seen under the hood of any of the
> Wankel-engine cars, there's a lot of space (except in the twin-turbo
> RX-7s and such, where the hood is filled with nothing but air
> intakes, turbochargers, intercoolers, and ducts, ducts, ducts.
>
> Mazda is bringing back the Wankel next year as a range extender for
> a primarily-electric vehicle (apparently on the Mazda 3 "long
> hatchback"/wagon), where it's located under the rear floor right in
> front of the bumper. Since it's running generator instead of driving
> the wheels, it's mounted horizontally for compactness. On a boxer
> could come close to fitting under the floor in the same way.

They are also a popular design for things like auxiliary engines on
yachts, where they'll sit unused (and unmaintained) for months at a
time, and need to be small, light, and highly reliable with this sort of
neglect. The relatively short service life of the seals isn't a problem
for this purpose, because their running time overall isn't very long
compared to that of a car engine (for example).

Another use is small aircraft and microlights, for similar reasons -
great power to weight ratios, relatively short running life acceptable.

--
Rupert Boleyn <xxxxxx@gmail.com>