High-mile expert here. Expect 100% replacement of wearables in all running gear - struts, bushings, steering linkage. Expect brake mechanicals - calipers, cylinders, rubber hoses.

Wheel bearings, maybe. At least inspect them.

If you’re pushing on 15 years, all rubber hoses throughout the car, while the OE custom shaped hoses are still made. You don’t want to replace one at year 18 after an extensive search and long wait to get a NOS OE part, then another in year 20, 3 more in year 21 remember you’re breaking down and having to be towed every time, and now you’re having to hork them together because the custom shaped OE stock is gone.

We don’t know yet. Age plays a huge difference in cars, more than mileage, and as such your question is very open ended.

Do you mean what happens at 300k after 20 years of averaging 15k each year, or what happens at 300k after averaging 40k for 8 years?

Or what happens at 300k after averaging 60k for five years.

Those are all going to be different answers, and so far we don’t even have enough statistics to answer the latter one.

Suffice to say, most ICE vehicles don’t reach 300k. I did have an Audi that passed 400k though.

And as others are pointing out, LFP batteries are likely to last longer as they have about 3x the cycle life of conventional EV batteries.

But battery packs are more than the sum of their batteries. BMS boards could fail, mechanical connections could fail, fuses can blow, etc.

EV’s are full of electronics and I wouldn’t be surprised if at a certain age electronic components reliability is going to favor reselling the cars for battery pack extraction vs. being a used car.

Battery storage could easily use a 15 year old battery pack for another 10 to 15 years, if not more.

As such used prices are likely to hit a cutoff threshold when they reach a certain age where the used market will be 1:1 with the repurposing market.

I stopped by a used EV lot 2 weeks ago. The sales guy (who spent almost an hour chatting with me) said he has a tester that gives him all sorts of info about the batteries, including what kind of charging its been using. he said the only batteries he’s seen with significant degradation have been air cooled - like the Leaf and the e-golf. So he wouldnt recommend those. that made me feel a lot more comfortable.

can’t say much on the 300,000km mark but after 8 months and 25,000km we have only needed tires done and wiper fluid, The drive battery has lost just under 1% on an LFP.

Yeah, 300km is not what it used to be on an ICE. A coolant/transmission flush and fill, plus some spark plugs. These will show up on an EV as well, minus the spark plugs, but you will spend way more on tires alone either way, so not something to worry about.

Thanks everyone. That’s good feedback. My OP meant what is to be expected at 300km in loose context