oil change interval

[jevanb]

I change my oil as often as I can with my 04 6.0 gasser I changed it @ 1000 ,2000 then went to mobil 1 @ 3500 and changed it every 4500miles, with the new LBZ I changed it @ 1000 rotella T will be doing it again @ 3000 w/rotella , when should i be thinking about going to mobil 1 and what interval, I know it is over kill but I like clean oil and do not mind spending a little more money to keep the crankcase cleen

[More Power]

Switching to synthetic at 3-5K would be OK. I'd like to see some towing in that time to help ensure the rings are fully seated.

An engine oil analysis would be the best indicator of when to change your oil. GM's 7500 oil drain interval works for some, but I'd change it at 5K if mostly towing miles. Oil will darken in a diesel engine as the miles accumulate - more so when towing. Change it when you can no longer read/see the stick through the oil.

Change the synthetic lube in the rear diff after 500 towing miles or 10K light-duty (non towing) miles.

Good luck,

Jim

[WILLYD-MAX]

I second what MP said on an oil analysis. I have done oil analysis on our 2 trucks and the oil was still usable at 7 to 8k using mobile synthetic with a lot towing. I have since become an Amsoil dealer and have switched to Amsoil 15/40 synthetic. You can go 12.5k to 25k with their high efficiency oil filter and their oil, depending on how you use your truck There is no point in throwing away good oil. You can use Blackstone Labs for an analysis or Amsoil. Just my 2cents.

[Pewter Max]

I just changed my oil today - 16k miles and a little over a year .
I have been using Amsoil 15w40 since my 01 had 5k miles on it , I had it analized a couple of changes ago with 15k miles on the oil and the report said the oil was fine and all I needed was a filter change .
It has 90k miles now and I added 1 quart since last change , this run had app. 6k miles of towing my 11k lb. Sunnybrook 5er - a lot of it in the NC Mts.
And it still has the same old Injectors !!
Amsoil Synthetic - Front to Rear

[jevanb]

I tow a 30tt 9k every other weekend around 90 1 way so the truck is working, I only get 9.5 pulling it which sucks because my father in law has the same truck and he is getting 13 pulling a 5er @ 13k, where is the best oil labs to use..

[Kennedy]

I change early and often as well. The switch to synthetic can be made as soon as YOU determine that it is economically practical. If there was a very minor price difference, I'd have Delvac 1 in at my first change, but since it's expensive, I wait until I'm comfortable running my oil 7-10k drain intervals which is around 5k. Oil analysis can be your guide and watch for the silicon to fall. I run the Uni foam filter and watch silicon content closely until it slows down its rate of descent and hits teens.