I used high mileage oil on my last oil change. Will using regular oil on my next oil change cause a problem?

Question

I have a 99 GMC Sierra with 135000 miles on it. I used Quaker State high mileage last time...any suggestions on another brand of oil?

Answer 1

Depends if its synthetic. most oils now are half synthetic but if you go full synthetic I would stay with it. I use Valvoline SYNPower, its full synthetic, its pretty cheep at walmart bout 20.00 dollers for 5 quarts, and valvoline high mileage for about 14.00 for 5 quarts.. they are both good.

Answer 2

regular quaker state high mileage is sued to swell the valve seals and prevent leaking into the combustion chamber. as long as  it is not a synthetic your fine.

Answer 3

no it wont cause no problems with it ,and the myth on using synthetic oil in one and then changing it back is false also you can use synthetic at any time and then change it back and it wont hurt a thing,it would actually help your vehicle if you was running synthetic oil in it it,its designed to work well with higher mileage engines,good luck with it.

Answer 4

No, will not cause a problem.

I use Penzoil (O'Reilly brand oil is made by Penzoil and it's cheaper)

Castrol GTX