One thing that always puzzled me was how the gas engines in hybrids were so efficient. Technology Connections has a great video explainer: <a href="https://www.youtube.com/watch?v=KnUFH5GX_fI" rel="nofollow">https://www.youtube.com/watch?v=KnUFH5GX_fI
tl;dw: constant RPM and a weird stroke geometry where the power stroke is longer than the other strokes to extract more energy from the expanding gasses.
I'm surprised there isn't more effort to create hybrids in reverse--an electric car with optional gas generator. The gas generator could run at constant speed, never changing RMP, while the battery handles constant changes in acceleration. The idea is not mine. I've heard about it in China
I think it's also because EREVs need a performant generator that isn't much different from the drive motor. So you'll have a full ICE+EV drivetrain on top of an EV as its battery for it to work, which is not ideal.
Compared to that, other hybrid systems like the motor-clutch combo packs that sit between the ICE and gearbox, as well as the fixed gear Toyota systems, can have motors that are weaker, lighter, and cheaper than the ICE, while being able to be additive to the ICE power output. That makes more efficient use of steel and copper than full serial setups.
BMW i3 had such EREV option, but it apparently used a cheap OEM bike engine(not like a BMW Motorrad engine) and also could not overcome power draw of the EV drive motor. So it literally just extended the range, not allowing it to run indefinitely at highway speeds with just refueling. Nissan e-POWER system is powerful enough to do that, but then the readers of comment will have to back to the line 3.
Yeah. I'd love a decent plug-in EREV in the US. The 2027 Rogue appears to NOT have a plug-in option at the moment.
I can't fathom buying an EV and still only getting 40 MPG and needing to buy gas. Ninety percent of my trips are < 40 miles round trip and could be handled by a modest 15kWh battery. For that last ten percent, I'd happily use some gas to not have to worry about charging on the route.
Mazda had (has?) some cool EREVs using rotary engines as the power plant. Though sadly without plans to bring them to the US.
gcanyon · · focus · HN ↗
tl;dw: constant RPM and a weird stroke geometry where the power stroke is longer than the other strokes to extract more energy from the expanding gasses.
jostmey · · focus · HN ↗
numpad0 · · focus · HN ↗
I think it's also because EREVs need a performant generator that isn't much different from the drive motor. So you'll have a full ICE+EV drivetrain on top of an EV as its battery for it to work, which is not ideal.
Compared to that, other hybrid systems like the motor-clutch combo packs that sit between the ICE and gearbox, as well as the fixed gear Toyota systems, can have motors that are weaker, lighter, and cheaper than the ICE, while being able to be additive to the ICE power output. That makes more efficient use of steel and copper than full serial setups.
BMW i3 had such EREV option, but it apparently used a cheap OEM bike engine(not like a BMW Motorrad engine) and also could not overcome power draw of the EV drive motor. So it literally just extended the range, not allowing it to run indefinitely at highway speeds with just refueling. Nissan e-POWER system is powerful enough to do that, but then the readers of comment will have to back to the line 3.
snitty · · focus · HN ↗
I can't fathom buying an EV and still only getting 40 MPG and needing to buy gas. Ninety percent of my trips are < 40 miles round trip and could be handled by a modest 15kWh battery. For that last ten percent, I'd happily use some gas to not have to worry about charging on the route.
Mazda had (has?) some cool EREVs using rotary engines as the power plant. Though sadly without plans to bring them to the US.