I just bought a 03 SD 4x4 and I want to run a synthetic. In my f-150 is used Mobil-1 syn and changed it about every 10,000. It had 155,000 and ran quiet as a mouse. Should I stay with Mobil 10-40 syn ?

 

What engine in the SD?

Jim

 

its an 03' 7.3l

 

Shell Rotella-T, 5w40 oil, would be an excellent choice for your '03 SD. It would also maximize your fuel mileage as well.

 

rotella syn 5w-40

run it 10,000 change filter every 5,000

 

I run rotella dino 15/40 around 5000 miles in my 7.3 with no problems.It is also an 03.

 

You can't use the mobil 1 10w40 diesel its not diesel rated. It has to be CI-4 rated.

 

but they do have a M1 5w-40 syn and there is 5w40 and 0w30 syn from Chevron Delo all are rated for the diesel

 

A UOA should be your deciding factor. I'd do one at 5000 miles, and go from there

 

Make sure you use a diesel rated oil, for sure. These oils are designed to hold and suspend various by-products that only diesel engines produce. That is a key factor, but I still stand by my 5w40 Shell Rotella-T recommendation.

 

Rotella T 5W-40 is quite a product. It is significantly less expensive than most full-synthtetics and yet it meets not only API deisel specs, but some very stringent VW and other proprietary specs as well. The base oil is Group III, but more like Group III+, becuase it is made by a different process. Shell Helix Ultra is made with the same base oil and is factory fill for Ferrari.

Jim

 

one thing i want to know is does the rotella syn have zinc in it

 

Yes, and more of it than most normally stocked motor oils available today.

Jim

 

good to know