[vvanders]

Well first off I'd probably never run a 15k interval. Pretty sure that's beyond mfgr spec. We run 7k in our diesel on full synthetic. Stretching a maintenance interval seems pennywise and pound foolish.

You also have to consider how much your time is worth of you're changing it yourself to get that cost.

Either way it's an added cost(along with transmission, differentials, etc) that you just don't incur on EVs. Right now my maintenance schedule is brake fluid @40k and coolant @100k and tires, that's it.

[jaggederest]

You want to do oil analysis like the professional diesel mechanics do.

Most people don't need to change their oil anywhere near as often as the manufacturer specifies. Especially for large diesel engines, it's often fine to run them 3x-5x the interval, but you should do oil analysis and find out, instead of just using the rule of thumb ones the manufacturer gives you.

[sunstone]

On my 2017 Prius oil changes are every 16000 km at the dealership.

[ollie87]

Heh, my car is on a 18,000 mile interval for the oil changes. It will also adjust based on how you drive it, it only asked for it's first service at 19,000 miles.