It's hard to find my oil of choice around here so I put Rotella straight 40 weight oil in my 525. Without turning into another messy oil thread I would just like to know your guys opinion on this particular oil. Most of the guys on Donzi.net don't think this is a good oil. I only plan on running it til the end of the season.

that oil is desinged for desials low rpm and has no anti foaming agents thats why not good for higher rpm engines i use brad pen

I have some knowledge of motor oils, although mostly through research as a hobby. Isn't 40W the correct weight oil for the engine? Rotella is a diesel quality oil which means it should have the additives needed in a heavy use gas engine. I don't see what could be wrong in using this oil in your engine.

I use shell rotella 15-40 diesel oil. Works great eve better price and you will find may use it on here

Just checked with the Shell site and they say there are anti foaming agents?

http://www.shell.com/home/content/ro...in_diesel.html

Yup along with detergents. If diesel oil can make a 700hp tractor trailer engine go a million miles I am sure it will be fine for a big block gasser

I have been told you also need an oil with the proper amount of zink if you are not running a roller cam. I dont have all the specifics but i was told that most oils these days dont have it or it is being eliminated and it is essential to cam lubrication. Anybody have any info on this? i was also told to use a good quality straight 40 wt by a Merc factory rep that runs in our group (good guy to have around for sure). He suggested either Brad Penn or Mercs house brand.

Both the multigrade conventional oil (10W-30 and 15W-40) and the synthetic SAE 5W-40 meet the newest API certification of CJ-4/SM.

Shell is marketing their new CJ-4/SM oil as "Triple Protection," meaning it provides enhanced qualities for engine wear, soot control and engine cleanliness. Shell's Rotella website indicates that on-road testing confirms the new Triple Protection technology produces better anti-wear characteristics than their existing CI-4+ rated Rotella oil. This is achieved despite a lower zinc and phosphorus additive level as called for by the API CJ-4 specification. (The 15W-40 Rotella T with Triple Protection oil has approximately 1200 ppm of zinc and 1100 ppm phosphorus at the time of manufacture.)

Everything I read Shell still has Zinc in their forumla just not as much but more than regular oil does. But as you read above the triple-T is suppose to replace the zinc funtion. Zinc has been more commonly used for breakins anyways

Good info. It was mentioned on another forum that this oil will foam up. It also seems that it doesn't contain as much zinc as it used to but my motor has a roller cam anyway. I guess it will be OK to run this oil for a few hard runs before I change it for winter lay-up?