[Auto_Clueless]

What is the best motor oil to use? Is there a very big difference on how the car run if you go for the cheaper one?

[UGoGirl]

I know that the worst kind of motor oil to use is dirty motor oil. I'm not sure there is much to be gained by using the most expensive motor oil, just keep it clean.

[silverfox]

I have not put oil in my car lately. I usually take it to the garage. But if I remember correctly, I think the heaviest oil is the best? The 30/30? Not real sure.

[MaximumSpeed]

I usually use 10w30, but for a long time I used straight 30. I didn't really notice any performance changes when I changed from one to the other.

[Lindsey]

The last couple of times we've used synthetic oil and have been very pleased. You can go quite a bit longer between oil changes and apparently it's easier on the inner workings of the motor.

[FenderBender]

I really don't think there is that much difference between brands if that's what you mean. You should consult your owners manual for the best weight to use in your particular vehicle. I use 10W30 in the summer and 5W30 in the winter.

[Alexus]

The brand is probably just a matter of preference, but you need to know the type of motor oil you need. Some oil is better for certain types of cars. Others are better for summer and others are better for winter.

[Tiger21]

I've gone back and forth between Mobil and Valvoline.

[RoadWarrior]

Brand choice is a matter of preference; one isn't any better or worse than the other. However, the oil you choose must have the American Petroleum Institute's starburst seal...

http://www.recycleoil.org/

It just says that this oil meets or exceeds car manufacturers standards.

As far as weight, the larger the second number, the thicker the oil. So an oil with a viscosity rating of 20W50 would be very thick; oil rated 5W30 is thin. Thick oil is for summer use, thin oil is for winter use.

Be sure to check your owners manual and use what they suggest.

[Flipit]

RoadWarrior, this is helpful as I always just go with whatever the service center says to use, or with whoever is changing my oil. I know it's not smart, but I've never sat down with the auto owner's manual to check oil issues.