wanting to switch oils in a used vehicle i just purchased. its an 06 chevy

[chance w]

colorado 5cyl vortech with 53000 m? the previous owner has always ran regular Pennzoil in it and i was thinking on switching it to a synthetic maybe.. ill be driving it mostly on the highway back and forth to work. would a synthetic or certain type of oil be better for it or help me get better gas milage??

 

[eric b]

The oil doesn't effect the gas mileage.Unless it hasn't been changed.I wouldn't change to pure synthetic oil.It may cause problems since it has already been using regular fossil oil.You can change to a synthetic blend that will be okay.I was told by a master mechanic that if you want to use synthetic that you should use it from the start.When a car's new.He said that you can change one back to regular oil but you can't change it from regular back to 100% synthetic.I trust him completely.He's my uncle and has been the head master mechanic for the state for over 40 years.

 

[T/A]

Synthetic Oil is a waste of money. It will not protect your engine any more it will just cost you over twice as much for a oil change.

When it comes down to it oil is oil the brand does not make a difference. Just maintain regular oil changes every 3,000 miles or 3 months which ever comes first and it will be good.


So basically just save your money and run petroleum forget about the over priced synthetic oils. Unless you just have pockets full of cash and are looking for ways to get rid of it.

As far as the once you change from petroleum based to synthetic you can not switch back.
The reason that they say that is because the petroleum based oil actually plump the gaskets were as the synthetic did not have these properties originally so you could actually ruin the gaskets in a engine from switching back and forth. Now a days the synthetic oils have been made to fix this problem and it does not really make a difference.