I wouldn't be that worried about it. The batteries have been shown to be quite reliable in the long term. Electric motors are low maintenance and very reliable. Then you have the ICE, which frequently shares the load with the electric motors. Depending on how it has been driven, you could have a hybrid with 100k miles on the odo, but may very well have significantly fewer miles on the actual ICE.

 

Sorry, it was a '97 Camry. My dad did have a '68 Corona and then a 77 Corolla as well. We are a Toyota family but somehow have not had good luck getting more than 120k or 130k miles despite doing regular maintenence.

 

So how come the power split device does not need oil changes. It is basically a planetary gearbox. There is wear, like ant other manual transmission. There would be little bits of metal going around generated as the gears rub against each other. Where do they go and why don't we have to change the oil?

 

Sealed "lifetime" trains fluid is a thing nowadays. I'd change it anyways.

I've never had a problem getting more than 120k out of ANY car.

 

If I were a betting man, ibwould put my money on a hybrid Toyota/Lexus outlasting a gas Toyota/Lexus. Toyota has put a lot of money into making sure their Hybrid Systems work. The future reputation of Toyota is on these hybrids more than they are on gas which whos reputation has long been established.

 

The vast majority of the wear in a regular manual transmission is on the synchromesh friction-cones, not the drive gears. That wear occurs during shifting, as the friction-cones engage to match the spin rates of the two gears before the gears engage. The syncro-cones are, basically, clutches. (The wear in a regular automatic transmission is also on the clutches, but they are operated differently.)

The planetary gear system in a Toyota/Lexus hybrid does not shift, and has no clutches or friction surfaces. All of the gears are fully meshed at all times. So there is much less wear.

In each type, there is a magnet in the bottom of the unit to collect whatever metal particles do get loose.

A standard transmission (with friction-cones) usually goes about 100k miles between rebuilds. Without the friction surfaces, a permanently meshed gear system can easily go ten times that far...

It might be wise to change the oil anyway, every five or ten years. But, these units take special oil (it has to be non-conductive). I would estimate the risk of a mechanic installing the wrong kind of oil as, higher than the risk of the original oil wearing out.

 

I always worry about the risk of the mechanic's work (or contamination) verses a sealed system.

 

Thank you! As a mechanical engineer I fully understand now.