Shell Rotella T

[stealth908]

ok, so I'm not really going to screw anything up...I've read, in different posts here, that the increased levels of phosphorus and zinc accelerate the wear of the catalytic converter, however, I like the idea of 1) a thicker oil, 2) an oil that protects my engine better, unlike modern SM grade oil, and 3) I want an oil with some detergent to help clean the engine (I know diesel oil has more detergent in it)

Bad idea?

No, not a bad idea. Run it. I am not just a bottle reader. I have built a couple dozen engines in my 31 years on the planet. I always do the same thing to them. Lightly lube the bearings with 5w30 moly lube the cam, pre-lube with 5w30, drain, breakin with 5w30, and 2 cans of GM EOS for 20 minutes, drain, 500 miles on Rotella, drain, 2000 miles on Rotella. Same ritual every time since my first engine back in 96. It is still running great in my dad's 69 C10. My race car engines get this treatment, as well as engines built for friends. I never have any problems... period. If the engine is a roller cam, I use Mobil1 10w30.

This article refers to a cam lobe wiping p[roblem that most turbo buick folks have. The #3 exhaust lobe is at a different angle than the others. This wiping problem has not been an issue until recently. Most believe it's because of the reduction in oil additives.
http://www.turbobuick.com/forums/general-turbo-buick-tech/176385-article-cam-failures-car-craft.html

This article is very good. It explains everything you need to know about oil, cams, additives, etc.
http://www.hotrod.com/techarticles/engine/flat_tappet_cam_tech/oil_summary.html

 

[rockjockphatts]

have any of you had any issues with blow-by before or after switching, or with detonation caused by blow-by due to the diesel oil's detergents creating gaps (by cleaning the rings, etc.) as mentioned in one of the tech articles posted by stealth (thanks btw)?

 

[skid_j2x]

Im running shell rotella 15w - 40 in my 2000.. thought i had a oil pump prob (loss of pressure at idle when warmed up) but it was just the pressure switch.. we run 15 40 in all our gas fleet vehicles ( '95 f150, 2000 e 350 v-10, 2000 dodge 3500 van, etc..) But straight 40 weight in our diesels

 

[stealth908]

have any of you had any issues with blow-by before or after switching, or with detonation caused by blow-by due to the diesel oil's detergents creating gaps (by cleaning the rings, etc.) as mentioned in one of the tech articles posted by stealth (thanks btw)?

no problem. My xj had a little blow-by already, and I'm pretty sure it's common for a 4.0 to have some anyway. A little is ok, but you'll know if you have too much. I think if the oil causes the blow-by because it cleaned out the inside of the motor, then it's time for a rebuild anyway. Or, atleast a re-ring, and head job.

 

[MAY POP]

10w30 Rotella is available at Tractor supply

 

[outlander]

thanks...I'll go there the next time I'm do for a change.

 

[PurpleCherokee]

I just very recently switched the full synthetic Rotella and I couldn't be happier with it so far. I also put some Lucas in the oil and I'm also a pretty big fan of that. I'm at ~50psi@70 and it quieted down those annoying ticks in the motor a lot. Also seems to be running as strong as ever so I'm gunna keep this reutine.

 

[Ecomike]

New (and old) Diesel oils have more detergent, phosphorous, than API SL or SM gasoline motor oils, and more zinc (ZDDP) than the new gasoline API SM oils. However, the old API SL oil had higher zinc levels than the new diesel oils do.

The reason EPA lowered the zinc and phosphorous limits in oils was to increase the life of catalytic converters from about 50,000 to over 150,000 miles. Most of our cats lasted 75,000 to 100,000 miles or more with the old API SL oil which had higher zinc and phosphorous levels than the new SM oil.