My Father, 81 years young, had an interesting qestion. He only puts about 4000 miles a year on his 1999. He has dino oil in it. I don't use dino anymore, based on the BB discussions. Based on oil properties, additives etc, should he change the oil based on time or mileage?

I go along with Ryan. I've opened up low mile engines and found them to be sludge factories because of minimal mileage and "3000 mile" (1 year) oil changes.

I would use mann filters and synthetic oil, change

the oil filter every 6 months to a year, and drive at

highway speeds for 30 minutes for every 5-10 short

trips I take. And change the oil every 5000-7000

miles. I think there are marine oils made by amsoil

for this sort of use.

chris

You should change your oil every 3 months reguardless of mileage. Sooner if you use normal oil, and travel more than 3,000 miles in a 3 month period. When the car sits, moisture can build up inside and dilute the oil. Also, dirt and other contaminates make it through the air filter and get in the engine as well. So to answer your question, it would be prudent to change the oil every 3 months even if you only drive 4,000 miles a year.