When should I get rid of my high-mileage car?

I’m approaching 193,000 miles on my 1998 Nissan Sentra GXE, and I’m in a quandary. When should I buy another car with lower mileage?

My Sentra, unlike the one shown here, is in fair condition. It runs a little more sluggishly and loudly than it used to. A small dent from backing into a friend’s car is noticeable, but not terribly so. The interior is clean and tear-free, with a few minor upholstery stains that I could scrub out.

My wife and stepdaughter see my Sentra as a “junker.” I see it as a wise choice for my driving needs. I’ve logged 100,000 miles in about four-and-a-half years traveling 105 roundtrip miles daily to work and the car has required just one non-maintenance repair of over $500. It’s 30 miles-per-gallon has been nice in this era of $2.50-plus per gallon gas prices. And I could conceivably sell it for about $2,800, according to Kelly Blue Book—an amount that’s held fairly steady even as the miles have piled higher.

Sell the car now or later?
With 200,000 miles approaching, I’m actually a little excited. Just how many miles can I get? But I also know I’m living on borrowed time. If the car does die, it will be worth nothing.

I’ve been watching the market for used Nissans, Toyotas, and Hondas on phillycars.com, a local car-buying site. I could get something similar to my Sentra with less than 100,000 miles for $4,000 to $7,000. M and I have some cash saved to get another car for me, but we also dip into that reserve when our monthly cash flow gets tight. A part of me wants to use that money for the car sooner rather than later, before we drain it completely.

Going to keep driving—for now
Still, I’m tempted to keep wringing as many miles as I can out of my trusty Sentra. There’s a good chance that it will die a slow death, with steadily increasing repair bills, rather than suffer a sudden automotive cardiac arrest. Then I could keep it running until I find a car and a deal I like, which is better than being forced to take whatever cars and deals are available at the time because I need a car to drive.

What would you do?