3 ms·

Sadly, the efficiency gained from being able to run the engine at a fixed RPM is lost in the conversion to electricity and back. This technique has been tried

Sadly, the efficiency gained from being able to run the engine at a fixed RPM is lost in the conversion to electricity and back. This technique has been tried a few times but it never works out in the end. The only time it makes sense is if you have a turbine engine, but since turbines have fairly lousy efficiency to start with this only helps get them back up to the baseline.

raihansaputra 2y ago
audi's dakar car (the rs-q e-tron) proves that it's at least more efficient than petrol based competitors. it doesn't charge overnight so always uses the energy from onboard fuel tanks, which are smaller compared to the other competitors. it doesn't reach peak efficiency of course, but still uses less fuel overall.
macbr 2y ago
Diesel-Locomotives (and apparently submarines?) use that concept a lot in the form of a diesel-electric power train[1]. Mechanical transmissions like in cars were only in use for a very short time. (You didn’t need them for steam locomotives as steam engines can start under load) Of course locomotives are a bit bigger than your average car... [1] https://en.wikipedia.org/wiki/Diesel–electric_powertrain https://en.wikipedia.org/wiki/Diesel–electric_powertrain
- Animats 2y ago
  > Mechanical transmissions like in cars were only in use for a very short time. Fortunately.[1][2] British Rail tried in the 1950s. Four 12-cylinder Diesel engines driving the the wheels through three differentials and four hydraulic clutches. The engines were geared such that the speeds added. As speed increased, more engines were turned on. Since startup only used one engine, starting pull was rather low for the engine power installed. Only one was ever built. [1] https://en.wikipedia.org/wiki/British_Rail_10100 https://en.wikipedia.org/wiki/British_Rail_10100 [2] https://www.youtube.com/watch?v=oYRZIQKMmWo https://www.youtube.com/watch?v=oYRZIQKMmWo

raihansaputra 2y ago

audi's dakar car (the rs-q e-tron) proves that it's at least more efficient than petrol based competitors. it doesn't charge overnight so always uses the energy from onboard fuel tanks, which are smaller compared to the other competitors. it doesn't reach peak efficiency of course, but still uses less fuel overall.

macbr 2y ago

Diesel-Locomotives (and apparently submarines?) use that concept a lot in the form of a diesel-electric power train[1]. Mechanical transmissions like in cars were only in use for a very short time. (You didn’t need them for steam locomotives as steam engines can start under load) Of course locomotives are a bit bigger than your average car... [1] https://en.wikipedia.org/wiki/Diesel–electric_powertrain https://en.wikipedia.org/wiki/Diesel–electric_powertrain

Animats 2y ago
> Mechanical transmissions like in cars were only in use for a very short time. Fortunately.[1][2] British Rail tried in the 1950s. Four 12-cylinder Diesel engines driving the the wheels through three differentials and four hydraulic clutches. The engines were geared such that the speeds added. As speed increased, more engines were turned on. Since startup only used one engine, starting pull was rather low for the engine power installed. Only one was ever built. [1] https://en.wikipedia.org/wiki/British_Rail_10100 https://en.wikipedia.org/wiki/British_Rail_10100 [2] https://www.youtube.com/watch?v=oYRZIQKMmWo https://www.youtube.com/watch?v=oYRZIQKMmWo