I’ve recently acquired a 1999 Pontiac Grand Prix. I hope to hold onto this car for the next five years or so (at least), and I have a few questions about its upkeep.
1. Mileage: It’s got about 145,000 miles; how many can I expect to get out of it total? I’ve heard of some getting upward of twice that amount before giving out.
2. Oil: Is it worth using the "High Mileage Fully Synthetic Engine-Cleaning Platinum" stuff in oil changes, or is it essentially all the same? Also, it has an "oil life" guage, which you’re supposed to reset when the oil is changed. Is this a good way to determine when I should change my oil? It just translates miles driven into a percentage of life left in the current oil.
3. Structural integrity: The underside is clean, but there’s some superficial rust in spots. I know I should get this fixed before it worsens, but will it last? (I live in northern Ohio, and winter/spring can get ugly.) How much will it cost? Also, should I get the car undercoated?
4. Paint: The clearcoat is peeling, and I’d really like to have it repainted. It’d look better and be less likely to rust. How much does a decent paintjob cost?
If there’s anything else you think I should know, feel free to throw it in. I appreciate any advice.