Which oils do you use??

[cheyenne1500]

Hey...I've been thinking about oils. I currently use the generic cheap diesel oils that you can get anywhere. I want to start to use a quality oil for tranny and eng. What do you think is best??

[Subzilla]

The recommended engine oils around this page are typically Shell Rotella and Chevron Delo 400 - 15w40 variety. I switched to Amsoil Synthetic some years ago but not everybody likes those for diesels.

[Kick Ass Matt]

I use Rotella T 15-40 but I do find it a tad too thick in the dead of winter. I want to try a different viscosity next winter, Canadian Tire sells a synthetic 5-40 Rotella but then is 29.99 for 4 liters. I buy the whole 20L pail of Rotella for like 44.99 so is kinda hard to justify...

[morgan]

My GMC has only had Royal Purple since new. The original owner gave me all the service info when I bought it. Actually, I didn't know where to buy it, and used Rotella for 2 oil changes, and lost a solid 1 mpg during that time. Now it's RP's Long Rider (formulated for diesels) only.

Also a big believer in Power Service Diesel Kleen (gray bottle) at each fill up.

[epa1775]

I use the Amsoil 15W-40. It's good for up to 25000 miles or one year, whichever comes first.

Pete

[Mark Rinker]

Mobil Delvac 15/40, 10K intervals.
GM ATF with 20K intervals, drain and fill, spin on filter (about 8 quarts)
Royal Purple or GM synthetics in rear diffs, 75K intervalsAll intervals shortened after towing during extreme conditions - i.e. heavy loads in hot summer conditions, I'll drop and change all three well ahead of schedule.

[murphyslaw]

good discussion HERE (http://www.thedieselpageforums.com/tdpforum/showthread.php?t=28853)

[GMC-RKL]

I have been using Royal Purple, first in my 93 GMC diesel, and now in my 05 Chevy Silverado Duramax. I have been happy with the results. I change oil and filter every 6,000 miles. I get plenty of oil pressure and a quiet running engine. I buy my Royal Purple from our local auto parts store - O'Reillys - in five gallon pails. It is a bit pricey, but most synthetic oil will be. It serves me well.

RKL