Some engines show signs of giving up by 100,000 miles. There are also those that last over a million miles thanks to loving and caring owners. However, there still seems to be doubt about hybrid powertrains and their longevity. But to settle that once and for all, YouTube channel speedkar99 tore down a Prius engine with about half a million kilometres, or about 310,000 miles.

But first, a background. The engine in this teardown is from the 2004 Toyota Prius. That means it's the 1NZ-FXE that undergoes some intense scrutineering here. It's a 1.5-litre engine with an Atkinson Cycle, so it's not too keen on producing power. However, it does make for it by maximising thermal efficiency.

The non-Atkinson Cycle versions of the NZ also made its way to various Toyota models from the past 20 or so years. Some applications include the Toyota Echo, Toyota Yaris, Scion xA, and Scion xB. While the 1NZ-FXE is no longer being used, the NZ engine series is still hanging around in the JPN Taxi with LPG power.

And now, for the main event, the teardown. So, how does a 2004 Prius engine that's travelled further than the moon fare after 17 years? Not so bad, actually, and it's still got several hundred thousand miles to go with a little bit more TLC.

Let's get the bad stuff out of the way first. speedcar99 took note of the engine's discoloration over time. That said, it's a bit of a given but there are a few things that knocked a few miles off of the engine's life. There are clogs in the oil control rings, so it wasn't getting the lubrication it needed at some point. Carbon has built up over the years, and sludge build up is evident.

But all in all, it's the usual wear and tear associated with high mileage engines. The advice here is pretty simple. Take care of your car and it will reward you decades of service. Granted, this particular Prius engine is nowhere near high-mileage hero Irv Gordon's Volvo P1800, but almost anything can last over 200,000 miles without a hitch if it's taken care of diligently.