I bought my 1990 Geo Metro from the original owner in 1992, with 58,000 miles on it. It was used daily for a 100 + mile freeway run; the easiest possible type of driving. The owner had been using Castrol Syntec 5W-50 synthetic oil, and had added an Amsoil bypass oil filter. I continued using the same oil and changing oil and filters regularly. The car is now 19 years old, and has run nearly 300,000 miles. I've replaced two timing belts, a water pump, an alternator, an oil seal, two sets of front brakes, tires, batteries, and tune up parts. The engine never had any internal repairs, has the original clutch, and runs better today than it did when I bought it (I am a professional mechanic).
I love the light, precise rack and pinion steering (no need for power steering here!!); the superb maneuverability in tight spaces; the solid reliability; the smooth and very peppy 3 cylinder engine; and the 47 mpg in city driving, with 55 mpg highway. I once got 58 mpg, with some special tuning.
I only wish they hadn't discontinued it. It gets better mileage than today's hybrids; without the complexity. Like most people, I had no idea how awesome this car is, until I drove it. People who say it is only good for local use are totally wrong. I have driven it on comfortable 1,500 mile trips.