Rotella T syn vs Moble 1 syn.

[Jimamatic]

Heard some talk a while back that Rotella T 5w-40
is not a true synthetic, even though it says full
synthetic on the jug. Can someone educate me on
this? How does it compare to Moble 1 syn? I'm
using Rotella T 15w-40 dino and going to make the
switch at 21,000 miles. Just want the best. Thanks.

[Modified]

I can't answer your question about the Rotella T 5w-40, but be certain, the ONLY Mobil Synthetic Oil you should be using in your diesel is "Mobil Delvac 1 5W40".
The typical "Mobil 1" oil you see in most of the stores (5W30, 10W30), is NOT recommended for your diesel.

[OC_DMAX]

Not even close to being an oil expert, but this is what I have learned over the years,,,

Shell Rotella Synthetic is based on a Group III base oil (highly refined petroleum oil). Mobil 1 Delvac (which is the only synthetic Mobil oil recommended for the DMAX) is based on Group IV & V PAO's / esters(a synthesized base). A number of years ago, in order to be considered a "synthetic oil" the industry standard was that oil basestocks of Group IV and V (PAO and esthers) be used. Castrol came out with an oil based on highly refined Group III base oil and called it a synthetic. Mobil (I believe) took them to court and objected to the term "synthetic" being used. Mobil lost. From that point on, the term "synthetic" has been blurred.

An excellent website to reference for oil questions is the following:

http://theoildrop.server101.com/ubb/ultimatebb.php

And both oils will work superbly in your DMAX.


Hope this helps,
Alan

[MaxACL]

I hope the Shell is good oil. I've been using it for a few years in my DMax.

Mike

[Jimamatic]

Thanks for the info. Since I'm not interested in
extended drain intervals I'll probably stick
with shell. As long as the price is right, I think
it's a good balance between economics, quality,
and regular drain intervls.