4 ms·
Still, though, series hybrids like the Volt and BMW i3 just use regular inline-4 gas engines taken from their other production lines. The Volt has basically th
by LeifCarrotson 6y ago
Still, though, series hybrids like the Volt and BMW i3 just use regular inline-4 gas engines taken from their other production lines.
The Volt has basically the same engine as in the Chevy Sonic or Cruze, and the i3 range extender option uses the same engine as their C600 series scooters. Those engines are designed with a quick throttle response and a wide power band to operate over an RPM range sufficient to drive a vehicle through a regular transmission.
I don't doubt that for the same time and money, it was far better for GM and BMW to take advantage of the economies of scale around those products than to design an engine specifically to function as a range extender, but if they really took this as a core function or started from scratch I expect they might select a medium-speed industrial diesel engine instead: something optimized for a particular speed and power output that does that one thing optimally.
- kevin_thibedeau 6y agoSame physical components doesn't mean that the injection mapping wasn't customized for the constrained application.
- LeifCarrotson 6y agoI hope they customized the injection mapping, but the GM LUU engine is still a naturally aspirated gas engine with 10.5:1 compression and 73.4 x 82.6 mm bore/stroke ratio, measurements which primarily came from the ICE-only target applications it was designed for.
- cmrdporcupine 6y agoAgain, completely untrue. A) Volt not a series hybrid B) the gas engine in Gen 2 Volt was not taken from their production line, it is an Atkinson Cycle engine designed for generators, not for their crappy ICE trucks and SUVs. C'mon, can people research before opining? "While it shares many parts with the new 1.5L I-4 used in other GM products, the Gen II engine’s combustion process and calibration are specific to the Volt. Its larger displacement not only improves fuel efficiency but also provides more torque, which contributes to the Gen II Volt’s surprising quietness." https://www.wardsauto.com/engines/gen-ii-chevy-volt-propulsion-system-shockingly-good https://www.wardsauto.com/engines/gen-ii-chevy-volt-propulsi...