Hi, I was wondering if there was a time interval for oil change?? I've got 4500 miles on this change, but it was done almost a year ago... Manual says 7500 miles but nothing about time. 05 ctd I do use rotella t syn. 5w40. Just wondering... Thanks Bryan

 

Amsoil recommends a mileage or 1 year max. I would probably dump that oil if it is a year old.

 

Yea I did, with cars 3000 or 3 months whick ever comes first..

 

If that is all the miles you will be putting on in a year I would do a change every spring and I would not even worry about running a synthetic oil.