oil viscosity

[Gordon Maney]

The owner's manual for my 2001 offers a drawing showing 15W-40 as a viscosity, and also offers a temperature chart listing alternative viscosities, depending on temperature.



What are most of you doing, are you running one viscosity year around, or are you actually changing with the seasons?

 

[EMDDIESEL]

15W-40 all year round. I use Rotella. Delvac and the cummins stuff work great too.

 

[HC]

As a synthetic user, I've had to not get overly excited about the owner's manual viscosity recommendations, because I can't follow them exactly. Two of the choices I trust are Delvac (5W-40) and Amsoil (5w-30). True, Amsoil also makes a 15W-40, but, eveyone doing oil analysis reports equal or lower wear rates with the 5W-30. If I were using regular oil, I'd go with 15W-40 year round in my climate (Southern US).

JOMO

 

[Bob Cochran]

15W-40 Dello year round. Few times in the mountains freezing and below worked okay also. It is not always 120+ here!!!

 

[merryman]

Delo 4oo, 15/40 year around--'course, here on the Oregon Coast, we have only one season-----wet and windy, all year,--lows in the mid 30's,, highs in the high 60's to middle 70's. Gets kinda boring .



Vaughn