older engines (like 150k ++) run better on dino oil because the clearances aren't as tight in the oil gallies etc. In older engines I would suggest dino oil. You definetely want at least 10w as well to keep the oil pressure nice and strong.

 

Why did you extend the interval?

 

Because synthetic is not supposed to break down as fast.

 

oil galleys dont have clearances...

if you mean main and rod bearing clearances, then yes.

 

it breaks down the same rate. But here is something that DOES NOT change:
The carbon in your oil. It does not matter how well it holds its vscosity, you are still running with DIRTY oil.

If you change your oil and filter every 3 K, it does not matter what oil you use. I splurge on synthetic for preference. and 27 bucks every 3-6 months is not that bad for me.

 

I should have taken a pic when the intake was off. pristine. I was replacing my plenum (never checked it, just preventative maint) and the plenum was not leaky at all. I could have eaten off it. It looked like bare, dry metal. That has nothing to do with the oil though, but the motor is very clean.

i do use lucas oil stabilizer as well. Syn always runs a bit thin so I add it to thicken it up. Plus two tablespoons of lucas assembly lube (extra zinc).

 

So do you think I am still ok at 6000?

 

weird how some of them get the crust, and some dont

 

Yea, the one's that go 6000 mile's between changes! LOL

 

HAHAHA amsoil claims 10,000 miles!