bullboy85

ok doing my first oil change on this truck. iv been told these trucks love senthetic oil with lucus. is there a better brand? how much oil and how much lucus? is there a better oil filter? is there anything i need to do to flush the old oil out to make the change to senthetic?

Formerice

The problem with synthetic oil, if you have a 99 with a lot of miles, it is so detergent it will clean out any buld up in your motor. One solution might be Next change use conventional mineral, Rotella, Delvac etc, but put in one or 2 quarts of correct weight Mobil one to bring it to full, then change it out at perhaps 1,000 miles. Make the switch gradually. Make sure that the synthetic is approved by Cummins. As far as Lucas ,I'm not an advocate of additives.

gunny

Look for the API rating on the oil jug. A diesel engine requires the CH-4, CI, CF stuff, look in your manual and it'll tell you what you need. Oils that are rated SK, SL and such are for gasoline engines. Some oils are rated for both, such as Rotella T. The "C" oils are compression ignition (diesels) and the "S" is spark ignition.

ShooterMagavin

I second that. If it is high mileage the synthetic oil will clean all the carbon built up between your pistons and your rings causing it to smoke for a while.

bullboy85

iv used cleeners and use the rbp additive that has cleaners in it. as long as it wont hert anything i dont mind the smoke expechely if it does what iv been told for prefomance and milage.

SMOKNISB

Just run Valvoline 15W40.

bullboy85

been told by to many people that senthetics really made there trucks come alive

Valv

I think you've been told too many tales....

Use standard Rotella 15-140 and your truck will last forever

Boss Hoss 540

I have run Syn for the last 20 years in my oil burners -- never any engine related problems on the Fords, Chevys, or my first Dodge which I am driving now. Some folks are just too cheap to run the good stuff.

supr

The conventional oils perform just as well as Synthetic. In some cases they do better, especially in the case of the new CJ, which is inferior in many ways to CI-4, for up to 2007 models. The Valvoline Premium Blue Classic is what was and is sold by Cummins outlets. The NAPA brand in CI-4, if you can find it, is similar. It has the best aditives package in the business.
Synthetics perform better in extremely cold or extremely hot conditions. They are more expensive with litlle quantifiable benefit, mostly feel good marketing.
Cummins makes no exceptions for oil change intervals based on oil type.
Buy the Valavoline, change oil & filer every 4-7k, sleep well at nite. Invest the diffrrence in a mony market certificate.
The main differrence, money in the bank.
Investigate/search some threads, judge for yourself.

afoulk

the past couple TDR issues, if you can get a hold of them, had really good articles on the amount of additives and detergents in the older CI-4+ and new CJ-4 oils, both mineral and synthetic. In almost every case, the synthetic stuff was better on paper than the mineral stuff. When it came to the mineral stuff, the older CI-4+ was better than the CJ-4 in almost every category. The Napa stuff was about middle of the pack (CI-4+), the Valvoline (CI-4+) being slightly better, and their synthetic (CJ-4) being closer to the top. I'd just stick with a good CI-4+ mineral if you can still find it. Its getting to the point where CJ-4 is all you can find.
As for the oil filter, I'd stick with Fleetguard filter with the *Stratopore media in it. Try Genosgarage.com for those. Sorry, I can't remember the part # for them off hand.

JSPulliam21

Oil filter: Fleetguard Stratapore LF3894.
Oil: Shell Rotella T, Valvoline Premium Blue, Mobil Delvac, Chevron Delo.
OCI: < 7000 miles without oil analysis.
Choose synthetic, real synthetic not group III petroleum, for severe duty. Severe duty to me is heavy constant towing, competition, extreme cold, or extreme heat.