From:Rob Olsen
Subject:RE: RE: ZDDP and Engine Oil Date:Fri Sep 14 09:24:31 2007
Response to:1676

Rotella T 15w40 is a conventional oil, they do make a synthetic 5w40, but I have not tried that and I suspect its a modified base stock as opposed to full synthetic.

In other countries Shell Rotella may also be labelled Rotella, Rimola or Helix ultra.

Other alternatives comparable to Rotella T 15w40 are Chevron Delo 400 and Delvac 1300. These are all diesel oils. My interest in the diesel oils stems from the fact that my truck has a Duramax diesel in it, and when I was specing out oils I came to the conclusion that these oils are perfect for my engines and have high zinc and heavy additive packages and make excellent choices for the application. Add some synthetic 2 stroke oil to your gas and you have a great combination.


Hello Dave/Rob , I have used a diesel 15/40 oil for about a year now on my bikes and am happy to continue , diesels are harder on oils than petrol engines so must be better ?? , it performs well especially as they all have the orriginal all steel clutches , which free easily and quickly , no more problems with sheered keys on the mainshaft !!! I found an interesting , if not anorack-ish article on oil , see the attached web site , I run oil filters on my bikes too and still change oil about every 1000 to 1500 (max) miles , Rob isn't Rotella T a fully synthetic ?? no good for all steel clutches ??
Happy riding all , Ken

I've read a bunch recently about ZDDP and the recent ~75% reduction of Zinc and Phosphorous compounds in regular motor oil. This is causing premature wear in flat tappet engines.


Some of the specialty racing oil makers like Redline have synthetic oils with lots of ZDDP & stuff, but I don't want to go synthetic.

How about the diesel-rated oils? I spotted Chevron Delo 400 LE 15W-40 in a local Pep Boys (no, they don't have the match books anymore). I called Chevron, and they knew the problem and recommended the Delo 400 LE for older flat tappet engines.

They said the "LE" was made specifically for the ultra low sulfur diesel road fuels mandated in 2007 - but either the Delo 400 LE or regular Delo 400 would be fine for this application.

Anyone have any experience using diesel-rated oils in old motorcycles? Do you recommend this?