ever since i have bought my truck, i have put 10w-30 havoline motor oil in it, would it hurt to switch to 5w-20 motor oil at 175,000 miles?

 

No it won't make a difference as long as you have some in there. It's not a high compression motor running at high rpms for long periods of time so no go ahead but why the switch?

 

Wont do any damage just as long as you dont switch from synthetic to convential assuming that you are using synthetic

 

i had a few mechanics from three different ford dealerships tell me if i use the thin weight oil that the truck and the owners manual says to put in it, it will have less friction in the engine with thinner oil and the pistons can move up and down more easier and frequently and i will se more peak performance, than i would with thicker oil, causeing more friction, plus they said with thin 5w-20, there will be less sludge build up and less power loss


did you understand that, cause thats exactly what i was told

thats why im asking you guys

 

Here is some info on the synthetic to conventional switch myth. Do a Google search and ever major oil manufacturer states it is not a problem.

http://www.lube1.com/factsmyth.htm#4

http://www.castrol.com/castrol/gener...tentId=7007980

http://www.mobiloil.com/USA-English/...AQs.aspx#FAQs5

 

im not switching to synthetic , i was thinking about switchin to thinner oil

 

Yes what they are stating is correct. You will not have a problem with using the 5w-20. Nowadays the engines are generally designed for a certain weight of oil.