3 ms·
I feel like at least some of this depends on whether the ICE in a hybrid is coupled directly to the wheels or not. I believe in all current consumer vehicles it
by mikepurvis 5y ago
I feel like at least some of this depends on whether the ICE in a hybrid is coupled directly to the wheels or not. I believe in all current consumer vehicles it is, but there are other applications like hybrid trains and city buses where the engine is just running a generator at a constant RPM. Surely that kind of configuration would be the absolute best case scenario for ICE efficiency, and probably even for overall system efficiency (with battery loses accounted for) depending on the ratio of city to highway driving.
- Robotbeat 5y agoIn a Chevy Volt, there’s a mechanism that mechanically attaches the motor to the wheels at speed above 35 mph for greater efficiency but below that it is a pure serial hybrid, disconnected from the wheel directly. But it rarely ever runs the engine. Pretty much only if you run out of charge.
- mikepurvis 5y agoAh, spiffy— that's neat to know that it can switch modes like that. Looks like this has been a matter of evolution over time, too: https://www.greencarreports.com/news/1096942_2016-chevrolet-volt-powertrain-how-it-works-in-electric-hybrid-modes https://www.greencarreports.com/news/1096942_2016-chevrolet-... I guess if you were only connected at higher speeds, that would also greatly simplify the transmission story, since you probably no longer need 1-3.
- Robotbeat 5y agoThe Chevy Volt actually uses a continuously variable transmission for that. Makes it sound really weird as there’s not a direct correlation between the sound of the motor and the speed you’re driving.
- tomatocracy 5y agoThere are some consumer BEVs with range extenders which work this way too eg the BMW i3. However they tend not to be marketed as PHEVs as such.