Change To Synthetic Oil After 100,000?

wotexva99 · July 9, 2009

I have a 01 1500HD that i purchased about 7months ago. I bought it with 102,000 miles on it. The first week i got it i changed plugs, wires, air filter, gas filter, trans oil and filter.

It now has almost 109,000 miles on it and i was thinking of switching over to synthetic oil on my next oil change. Would this hurt my engine? Do i just do a regular oil change w/ synthetic or do i need to flush the engine? If so, what is the easiest way to flush all the oil out?

Spurshot · July 9, 2009

You don't need to do anything different. Just change the oil to synthetic if you're planning on using Mobil 1 or Castrol. I dunno about the Amsoil and Deep Purple stuff. With Mobil 1 and Castrol you can mix with mineral oil if a quart is needed and nothing else is available. Fully compatible. The synthetic will provide better high heat protection and low temp startup protection. We don't have near the low temp problem in SoCal that the northern guys do, but a trip to the mountains in the winter and a morning start will cause the oil to thicken and synthetics don't thicken as much and provide better lubrication. Just do it like you would for mineral oil. You can change it at about twice the interval as mineral oil or do like I did, just change it when the light came on.

Draenor · July 9, 2009

I dunno about the Amsoil .....

Its the same. Just drain the old and add Amsoil.

ColoradoSkiCountry · July 10, 2009

No need to pay extra for Amsoil when Mobil-1 will work just as well but for less $$$ (Not dissing Amsoil, I just hate spending more money on things that you can get for cheaper that have the same purpose)

I have a suggestion for ya, your next oil change use a Synthetic Blend, then on the next oil change (2000-3000 miles) go to full synthetic. Good way of doing an "oil flush" without taking it to the dealer. Make sure you use a good filter! I like the AC/Delco & NAPA Brands.