How do Hybrid cars (or any car that ‘cuts off’ when idle) not just blow their starter or have massive wear on the engine?


Basically the title. I was always told most engine damage is done when starting the car, I live in a city and see and hear cars cutting off at every stoplight. How does that not blow the starter or engine?

In: 6

The starter motor is build for this additional usage with more durable components. The mechanism is also only engaged when this can be safely done, so on a warm and properly lubricated engine with a full battery, otherwise the system will simply keep the engine running.

My car has this “feature”, thankfully there is also an option to turn it off. Granted I have to hit that button any time I start the car but still. When growing up I was told the same as you OP, that the hardest thing on an engine is starting so I don’t really understand this thing they have added to vehicles.

Starting the car is hard on the engine because after it’s been sitting a while, the oil has all drained out of the cylinder head and valve train, so they run with little to no lubrication at first. Because it takes a while to drain, it’s not a problem at short stops at traffic lights and such, so all you have to be concerned with is the starter itself, and the starters in cars with this feature are said to be more robust than in cars without it.

The issue with starting a car is that there is no oil on the metal surfaces and they rub together un-lubricated. With start stop, there isn’t enough time for the oil to drain out of the engine, so all the parts remain lubricated, so no extra wear.

They use much larger starters, and may replace the alternator and starter wth on electric motor (mild hybrid). Instead of a 1hp electric motor, it’ll be 10+ hp. On a full hybrid, the electric motor will have the power to move the car, so no issue just starting the engine.

My F150 doesn’t use the starter in this process. The computer injects gas and then fires the spark plug on whichever cylinder is ready to fire.