My truck has 105K miles on it and up to this point i've been using the mobil 1 5W 30 supersynthetic... Well now that it has so many miles I figured fully synthetic oil might not be a wise idea anymore...I notice few autozones sell moblil 1 10W 40W synthetic blend for vehicles over 75,000 miles.. It comes in a white bottle with a green or gold top... I use this in my 200K mile 89 stang and works great.. Should I do the same with my truck or continue to use the fully synthetic 5W 30?

 

If you aren't having a problem running the 5w30, I would stick with it.

 

Or you could step up to 10W-30 mobil 1. It has a slightly thicker viscosity which will help to curb oil consumption and yet not change the chemical makeup of what you've been using.

Rich

 

There's no reason or advantage EVER to change from a synthetic to petroleum (or mix) oil regardless of miles. You will just accelerate wear and increase sludge build-up as compared to a fully synthetic.

Anybody who buys your truck later on will be happier also if you always ran (pure) synthetic.

 

What Hatch said and stick with the 5w30 or 5w20 that I use with 80,500 trouble-free miles.

Dan

 

Stay with the full syn. No reason to change. The synthetics are superior to the conventional oils.

 

WILL DO...


THANKS GUYS

 

Stick with it. My 88 Bonneville has over 350k on the original motor using Mobil 1.