I think the best oil to use is CLEAN oil. I'm of the school that uses major brands of oil and filters. Cheapest maintenance you can do. NAPA oil is made by Valvalin as is Carquest's.
IMHO synthetics are not cost effective. Given all things equal except the oil I can get 300,000 on an engine using non-synthetic. Let's see 300,000 divided by 3000 means 100 oil changes. Regular oil @ $2.50 per quart x 5(qts) X 100 = $1250 for the the life of the engine. If I have to pay $7.50 for synthetic (and sombody said $9?) Then my cost for oil triples or quadrupals. That's an additional $2500 or $3750 just for oil. Want to drive the car farther? Then for that price I can buy a rebuilt engine and have it installed and go another 300,000 miles or save enough to paint the car at 150,000 miles and feel like I'm driving a new car. Or take an additional 8-10 days off from work every year and don't drive anywhere.
Better gas milage with synthetics? bosh - What you have to look at is operating cost/mile driven. Adding $25 of operating cost per 3000 miles is 10 gallons of gas or 250-300 miles you could have driven for the same price. That means you'd have to get 8-10% better gas milage just to break even. Checking the air in the tires on a regular basis will get you that.
I think that repairing my own cars and having them run longer/cheaper/better than the average person is more environmentaly friendly than going down and buying a new car every 5 years. Making a new car is not environmentally friendly, not at all. Nor is using synthetic oil. Nor is paying interest on a bank loan.
This from a 1988 Sundance Operating manual:
"SAE 5W-30 engine oil is prefered for use in all engines..[ up to 100 degrees F]. You are highly encouraged to use SAE 5W30 engine oil to aid in low temeperature starting and for improved fuel economy.
"SAE 10W-40 and SAE 10W-50 engine oils are not recommended for use in any Chrysler Motors vehicles. These oils should never be used in any turbocharged engines"
Edited by stevemc, February 4, 2007 at 11:31 pm.