The relative value of a vehicle dictates how costly of an oil change programme should be. A nice new car that could use a fine oil should get it, a cheap old car, once a year with dino.
Change intervals based strictly on time with oil *quality* based on miles is my scheme. 10,000 miles a year in a cheap car means cheap oil every 6 months. 15,000 miles in that same car means good synthetic, still twice a year. 20,000 miles a year (me) in a nice car means 3 times a year with GC or M1 0w-40, 7000 miles per. I know in advance to change oil in all the cars I service (except mine) together in a group, and what it will cost over time. Very convenient.
Looking at it as a budget, for $100 a year an average person could get 2 dealer changes with M1, 12,000 miles. That person could get 3 dino changes of 4000 miles instead probally for the same price. Which is better? 6000 miles synth or 4000 miles dino. Fresh oil 3 times seems better, but I'll take the good synth twice, my car needs good oil and it is more convenient since I do not use Quickie-Lube, dealer only.
[ November 03, 2003, 12:16 AM: Message edited by: TSoA ]