Just bought my truck. Thanks everyone's help. I searched for oil changes and now seem to be more confused then ever.

1. At what point can you switch to synthetic oil?

2. Does anyone know what GM puts in the truck from the factory?

3. Amsoil - Some say its great and others say it not? What type would be safe.

Thanks - I am trying to read as much as possible and learn about diesals.

:help:

There is much debate on this subject. Some will say first change others will tell you wait till 10K. You are going to have to do what you are comfortable with. I am changing over at the 10K mark. It will be Rotella or Shaeffers syn I have not decided yet. I still have 4K to go before the switch. My local shop who does most of my work is a Amsoil dealer. He is really trying to get me to switch all of my trucks over to amsoil. I am still not sold on the product yet. I am going to try it in my 03 gas HD first.

Mobil 1 full synthetic, is factory fill on Corvette, Porsche, AMG Mercedes, and a few others I can't remember right now. My dealer did not think it was a good idea to switch mine over until 20,000km. I did it anyway at 5,000km with the mind set if it is good enough for factory fill on the above mentioned vehicles, it will be good for my truck. Just my 2 cents. The oil I use is Mobil Delvac 1 5w40.

personally I say you should let the motor break in first on the factory oil..meaning, go to the first oil change at least before you switch. The metal parts have to get to know each other and switching to synthetic too soon, in my opinion, doesn't let that happen to easily.

I took out the factory fill at 500 miles, and replaced the filter.

I'm running Mobil Delvac conventional 15W-40 now as the first replacement. I plan to run this for 3000 miles or so, then switch to Mobil1 5W-40 from then on.

the 10k mi. before the change to syn. sounds right (thats my plan also) using mobil delvac 15w 40 till then. my syn.oil of choice??? i always used mobil1 but dont know that grade to use 5w-40 10w-30 ect. ect. maybe by then mobil will come out with a 15w-40 syn. 2 oil changes to go 3000mi. oil changes is my thing

Just as 2500HD04 said, I am waiting for the full switch to synthetic for a few more miles, i'm in the low 7K now. I have added 2 qts of 15w 40 synthetic in the meantime. However I will be switching to AmsOil with Full ByPass filter, it's sitting on the shelf waiting to go in, pulled it off my 02. I had over 24K on the AmsOil that I was using in my 02 and the oil testing still came back perfect. (Independent oil analysis) Everyone has an opinion, of course... but I think you need to go with what your comfortable with. I swear by AmsOil, others Mobil 1 yet other Roella. I have heard great things about all of them. I just liked the full package I seemed to get with AmsOil, filters, all the fluids etc. I have run it in everything I own and do oil analysis. So far so good everythign is great!! My couple of pennies of course.

Oh yeah going to run and was running the 5W 30.

:blahblah:

My experience has been to wait and let the motor break in. When we bought my wifes used Passat the thing burned oil like crazy. 2001.5 with 18,000 miles on it when we bought it. I had the dealer pull the maintenance history and discovered the previous owner had put synthetic in it at around 1500 miles. Went back to regular oil and took a 1600 mile trip - running 80 mph all day long the thing finally quit burning oil.

Similar story with my brothers 02 2500 8.1 HD. Previous owner went to synthetic at 1000 miles. Thing never did quit burning oil. My brother finally got a new motor out of the deal.

I have never kept a truck long enough to see any advantages from running synthetic. prior to that, all used, just kept the oil changed regularly.

74 ford I-6, 3 on the tree,:driver: blew up, no oil:eek: ...sold
90 ford 302 v8 5 spd, 4x4, no power-:t ...traded
91 GMC,1500, 350 5 spd, 4x4:ro) , shoulda kept this one...traded :duh:
94 chevy,1500, 350 auto, 4x4 :cool: ...sold
71 chevelle SS, auto ...keeping this one:exactly:
haul it w/ the dmax
94 chevy, 2500, 350 auto, 4x4 :badidea: , burnt 3 trannys... traded
98 chevy, 2500, 350 5 spd,8 lug, sunk:drinking:...traded
02 chevy, 1500 Z71, 5.3, auto, not enough torque...traded
03 chevy, 2500HD, 6.0, 5 spd, Hypertech, clutch wouldnt hold, :wtf1:
traded

finally got something with some power and torque
smoked em in the driveway yesterday:exactly:
saw the light with the DMAX :hail:
think I'll stick with plain ol oil, just what the book calls for,
BTW, that book can be found in the glove box