Car Mechanics: Your favorite motor oil and why. What viscosity do you use?

I don't worry about the brand as long as it meets the specification for the engine. The API spec will be listed on the container.





Viscosity? Multi-viscosity oils are probably better than years ago with the additive package lasting longer. But as the miles pile up, the viscosity range diminishes and eventually it鈥檚 a straight weight. 10W30 is probably the best all around; 10W40 if it鈥檚 really hot. But the more you try to stretch the viscosity the more problematic it becomes. 5W30 or 5W40 are used by OEMs for certification because they think they get better mileage during start up. But good lubricity just isn鈥檛 there.Car Mechanics: Your favorite motor oil and why. What viscosity do you use?
Mobil 1 is good, but expensive. A synthtic bled is good to at a better price. Viscosity...depends what the normal temperture of the area is.Car Mechanics: Your favorite motor oil and why. What viscosity do you use?
5w30 semi synthetic Valvoline for a 1993 350 GMC


good value, I change oil every 3000 miles.


An engine overhaul at 140,000 miles


proved NO significant wear to bearings.


If I was more of a NHRA fan I would us CASTROL .


{ ForceFully }
Mobil ONE 10W-30....consistency is VERY dependent on which and WHAT kind of vehicle you drive...Although Mobile ONE HAS been tried, tested and proven by Consumer Reports and Motor Trend to be one of the best oils out...well thats my 2cents