Estimating repair costs?

I’m trying to finalize a decision (discussed in another post) about whether to repair my old car or buy a newer used car, and am trying to address the financial side of it. (Thank you again to all those that weighed in on the various issues previously).

Although I know there is no perfect (or even very good) way to ever know when any car is going to need repairs or for how much, is there any most sensible approach to estimating yearly or longer term repair and maintenance costs? (In my case, the two cars are an '89 Corolla at 189k miles vs. a 2004 Camry at 150k miles. And also if I consider other nearby cars for sale, or for the (let’s hope far) future.)

I’d say …no
You can have two identical vehicles…that each have completely different usage and maintainence results over time .
One can blow a water pump without warning and the other can go 200k without a seep.

Keep a thousand in a repair fund, just because. Then you can quicky agree to a needed repair without the wait for funds, plus you can make a deal for a cash discount as well.

I’d budget for $1200 per year repair and maintenance cost on the Corolla and $1000 on the Camry. $2200 per year total.

As said above, there’s no way to know of course how much it will actually cost. I have an early 90’s Corolla, so the $1200 per year is probably a little better than a wild guess, but it is still a guess.

If you wanted a better estimate, you could use AllData to find out the estimated repair costs of items you think will require repair. For example, it will tell you how much it costs to fix a bad CV joint, etc.

On one car, I figured out the average and marginal cost per mile for every 10,000 miles up to about 400,000. It is futile to predict. The maintenance and repair costs at each juncture over the first 100,000 miles were near identical, except for the occasional large expense being added. Then it took 50-100k to average out again and get my money back. So the answer is if you invest $3000 in a repair, you just have to be willing to continue driving it again for another 50-100k. So at 200k, are you willing to drive it till 300k or just junk it. That’s the only question. I’m no longer willing to do either.