When do you replace a DD if it's not when you're bored?

I sometimes recommend to customers that they set a dollar amount that makes sense for a repair at which they will replace rather than fix.

For example "I will keep driving this car until it needs a $1000 repair, then replace rather than repair"

Another would to be add up your repair bills for the vehicle for the past year and find a monthly average. If your maintenance is costs are the same as a new car payment, you may as well have the new car.

For me? I replaced my last DD because I could stick my arm through the rear strut towers. I still liked that one. It's replacement I may replace this summer because I find it to be kind of boring.

In Tuna's case, when the cost of repairs, singly, or aggregate, cost more than the vehicles perceived worth.

If your minivan's value is say, $4,000, and a new transmission is $1,000, is it worth 1/4 the value of the van?

Right before the transmission packs it in. Generally when a tranny goes there's a very good chance the cost/time/effort exceeds the value of the vehicle and possibly the cost replacing it with a working version - or other similar monster expenses like an Audi v8 at 70,000 miles.

So what is the transmission lifespan? What's the value at that mileage and cost of a good transmission. What's your time worth or what does downtime cost you?

A minivan with 110,000 miles is pretty much worthless in the greater scheme of things. Start putting away a monthly payment that would buy you a new one, then drive the old one until it explodes. If you need to make a long involved road trip, rent. If it survives for three more years, you have $15-30,000 in a bank account somewhere...that hasn't been spent on a new project car or shoes, right?

Totaled, totaled, irreparable. That has been my track record.

I replace my car when someone crashes into me and totals it.