My answer is a combination of 1 and 2. Two new '08 Toyotas require oil & filter every 5K or 6 months to maintain warranty. We drive perhaps 1500 miles in six months (if that) so synthetic would be an absolute waste of money. For example her car was brought home Christmas Eve of '07. As of July '09 it has had three oil changes and only has 3300 miles on the clock. Just not worth synthetic. Dealer uses Mobil 5000......which will never see 5000 miles!
Each vehicle has a 6.5 quart capacity so that's 26 quarts per year for two vehicles! Dino it is , dino it shall remain.
Each vehicle has a 6.5 quart capacity so that's 26 quarts per year for two vehicles! Dino it is , dino it shall remain.