I have a 99 Sienna that I recently switched to M1 10w30. Even at 1500 miles, the oil looks dirty and beat up---that must mean it's doing it's job keeping this engine clean! I used Chevron 10w30 and a couple Neutra treatments prior to switching to M1 at this last drain.
One unexpected nicety of M1 that I've noticed is that the temp gauge reads slightly cooler all the time even in this hot weather lately with M1 compared to any dino oil I've used.
Seeing M1's specs of 5w30 vs 10w30 is only 0.1 higher viscosity rating at 100C for the 10w30, would it make sense just to use 5w30 instead of 10w30? Would fuel economy be any better? Would it matter at all?
One unexpected nicety of M1 that I've noticed is that the temp gauge reads slightly cooler all the time even in this hot weather lately with M1 compared to any dino oil I've used.
Seeing M1's specs of 5w30 vs 10w30 is only 0.1 higher viscosity rating at 100C for the 10w30, would it make sense just to use 5w30 instead of 10w30? Would fuel economy be any better? Would it matter at all?