Synthetic oil 5w/40 or 15w/40

[ak diesel driver]

I've got 5-40 full syn in my work van right now and I found when it was hot this summer my hot idle oil pressure sucked probably 20psi, normally pegs the 80 psi guage

 

[turbovanman]

I've got 5-40 full syn in my work van right now and I found when it was hot this summer my hot idle oil pressure sucked probably 20psi, normally pegs the 80 psi guage

What's wrong with 20 psi at idle?? :???: If your pegging the factory gauge to 80 psi at idle, then you have sender or gauge issues, no way our engine can produce 80 psi at idle unless the oil filter/oil cooler and the all oil passages are plugged solid.

 

[ak diesel driver]

did you read my sig? my van has a 4bt in it.

 

[turbovanman]

did you read my sig? my van has a 4bt in it.

I didn't but even if I did, how the heck would I know that? and still, 80 psi hot at idle? No way.

 

[guybb3]

For what it's worth, I've used Mobil 1 5w-40 synthetic since break in and have 241,000 on the Sub now. It started without being plugged in at -20 F in Newfoundland about 10 years ago and I change the oil every 20,000 miles. Read my sig. about my filtering setup before anybody strokes out about the long change intervals.

 

[ak diesel driver]

Even if the factory guage is off it still reflects a huge change in pressure

 

[great white]

Optimizer 6500.

Rotella T6 5w40. Mobile 1 M1-302 filter.

60 psi cold idle, 40 psi hot driving, 35 psi hot at idle.

I change it at the recommended intervals, regards of synthetic or "regular" oil.