Oil viscosity
 

My 06 Mustang GT is in the shop getting some work done. I would like to pick up a case of Royal Purple after work but I can't remember what viscosity oil I need. Can anyone here help me out?

usually either 5W-40 or 10W-40. i am running 5W in my mustang.

Stick w/ 5W20. The VCT system in your car is designed for that viscosity.

Also, I would never run something as thick as 5W40 or even 10W40 in my car, as it will not only kill mileage but hinder the flow of oil.

w00t to that. 5w-20 on stock bottom ends.

Checkout the new Mobil1 0w20 oil, its supposed to give a nice boost in fuel economy and costs the same as regular Mobil1.

That's pretty interesting. It also says its safe to use on cars designed to run 5w-20 (which is us).

Yeah that's what its for. They say the same protection and better mileage and they have a calculator to see how much you could save. Mine was something like $124 a year with only swapping to that oil. If I had known about it before I changed my oil last week I would of gone with that over regular Mobil1.

Haha I know what you mean. I just changed my oil two weeks ago. Next time I'll have to try it out.

If the weather holds out, I might change mine early after I toss my bottom end all over the track on Wednesday lol.

LOL thank you.. i ment W20.... not 40....