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Engine starting and stopping is bad - what about hybrids then?


Topic starter


 I recently bought my first Toyota ever, a Rav4 Prime and love it so far. I didn’t purchase an extended warranty but then saw your comment about where the damage happens to an engine which is at engine start.

Given that hybrids start and stop all the time especially the plug-in ones how is this not reducing the overall life of the gas engine?  Same goes for all the regular gas models that shut the engine off at red lights.


1 Answer
  1. hybrid engines are usually quite small, so starting them doesn't require a lot energy
  2. Hybrids use the massive electric propulsion motor to start the combustion engine. (not a separate small starter like conventional cars). It's large and powerful, and can easily handle being stopped and started many times, because it has to.
  3. Hybrids use the electric motor to get the vehicle moving. The combustion engine is usually only started once the vehicle is already moving. This reduces the load.
  4. the combustion engine shares the workload with the electric motor. It's never pulling the entire weight of the car. This also reduces the load.


Conventional cars with Stop/start work very differently.

  • It uses small starter motors, and often they have to spin up huge, heavy, V8 engines.
  • It's starting at stop lights, and has to get the vehicle moving from a standstill. This is when combustion engines are least efficient, and a lot of wear happens.

1. Generally hybrid engines are usually quite small, but not with the Toyota new Dynamic Engine. The engine in RAV4 Prime is A25A-FXS, putting nearly 180hp with the big battery has 300+ combined. I look up the info on wiki, FXS hybrid and FKS non-hybrid are the same sizes ( I could be wrong, but I bet there aren't many big difference in terms of size)

@runningman I still consider 2.5L a "small" engine

lol it's pretty big for me, I drove a 1.4t Jetta for 2.5 years and my wife has a 1.8L corolla, so I have the biggest engine in my househhold lol