Finally got around to reading the owner's manual for my '91 Volvo wagon. It says to use premium gas (91 octatne). I'd put in two tanks of regular (87 octane) and the car seemed to run fine and I got around 26 mpg. Put in premium for the last tank with no improvement in mileage or performance. The 20-cent difference between regular and premium not such a big deal with gas prices over $2 a gallon, as long as the mileage improves, so I'm inclined to go with the good stuff. But I'm interested in your opinions about this.

Now as to motor oil, can these legendary Volvo engines operate forever with regular old 10W-30 or should I be putting in a synthetic or a blend made for cars with high miles? Mine, by the way, has 120k. I want this to be my last car, or at least the last once until a company as good as Volvo comes out with a hybrid.