CapnRam

Just wondering when i can switch the new truck over to syn. oil, its got 3000 miles on it now, i know when i'm building gas engines i don't go to syn. until around 7500, unless they have been dyno'd. And is there a warranty issue using syn. oil thats not MOPAR... in my 99 i use Valvoline Premium Blue full syn.,,and its got the cummins approval right on the jug. Thanks for any info..

Capn

JohnInNH

*I* would wait till 20K miles. Let her break in with dyno first.. Then swap over.

nelrod

On the other big diesel site, I read a letter cummins had responded to, answering your question. In a nutshell, it said to wait till 20K miles. Others have done it sooner without problems, but that what the people that build them say, 20K miles, then synthetic.

MOJO1

From new i have run AMSOIL in my 03 04 05 06 no problems at all.As soon as the weather breaks im going to do the trans, difs, to i beleive in it.

nelrod

Yeah, Ramble bee, I just did my G-56 with Ams. atf+4 and liked results. I have the 15W-40 Diesel and marine Am. ready for next change.

ASHNBAK

I did the Synthetic Rotella at a little over 30K and now have Delvac 1 in for the first time. We hit the upper 20's here in Socal last week so it kind of made feel good to have the synthetic pumping. Real truth is the Delo 400 is probably as good as anything.