Does anyone have an opinion as to how many miles we should have on the truck before a switch is made to synthetic oil???

Also, what is the best synthetic for the diesel??

I switched mine over to synthetic on the first oil change...was using Mobile 1 turbo diesel, about 8.00 a qt....Went to Wal-mart and found Rotella synthetic for 16.50 a gal.:D Rotella is a good oil for the diesels.;)

Schaeffer 5-40 with moly

x2... Schaeffer 9000

Does anyone have an opinion as to how many miles we should have on the truck before a switch is made to synthetic oil???

Also, what is the best synthetic for the diesel??
JBL, fill out your signature so a realistic answer can be given.

I use Amsoil Series 3000 5w-30 in my 2002 Duramax.
I changed oil and filter a few quick times before putting it in.

Many new vehicles come with a factory fill of synthetic oil. So I wouldn't hesitate to use synthetic oil at the earliest opportunity. In the old days they used to say to wait about 10k to allow the engine parts to wear in properly as the synthetic oil was so slick it wouldn't let the parts wear in. Todays engines have much closer tolerances and don't need long break in periods. I've not heard of any bad synthetics, so as long as it meets the manufacturers requirements for service rating and viscosity, go for it! If nothing else, it's peace of mind.

Thanks. Not sure what the signature has to do with it, but if you want to know what I have it is a 2007.5 2500 CC Duramax/Allison.

Again, Thanks!!!!

Thanks. Not sure what the signature has to do with it, but if you want to know what I have it is a 2007.5 2500 CC Duramax/Allison.

Again, Thanks!!!!

Because your LMM DMAX requires CJ-4 oil my friend where older D-Max's do not. Additionally not all synthetic and dino's have become CJ-4 compliant. Folks seem to be simply trying to understand your application so that they can provide a good answer.

Schaeffer 5-40 with moly

Same here. Schaeffer's 9000 full synthetic. I'd switch on the first oil change. The "break-in" will happen with synthetic oil, just at a slightly slower pace.

Most of the break-in will happen inside of the first 1,000 or so miles, anyway.;)

I Switched To Mobil 1 Synth Diesel Oil At 8k Miles......and It Is Cj-4 Rated For My Lmm

Rotella is a little cheaper as it is made with group 3 base stocks. IMO, if spending the money and effort for a synthetic, might as well go group 4.
I put in one vote for AMSOIL:)

is mobil 1 group 4?

I did the switch at 5k..see signature below ....amsoil products are the way to go...and no , i'm not a dealer..

Mobil is group 4.

what do yall think about Royal Purple?

I changed to Amsoil CJ-4 at 780 miles on the truck.

i switched to amsoil 15-40 at 5000 miles. benn good so far.

Rotella is a little cheaper as it is made with group 3 base stocks. IMO, if spending the money and effort for a synthetic, might as well go group 4.
I put in one vote for AMSOIL:)

I would go with Heath's recommendation - he knows his stuff. I run Amsoil 5W40 Premium Diesel oil in my LBZ as of the 1500 mile mark.

How often should I change oil with Rotella Syn. 5w40? Please let me know how many miles and/or how many months.

Since they don't give a recommendation above and beyond the manuf. intervals(7500-10000), I wouldn't go any farther unless sending in an OA. Based on that, then you will know how far you can run in the future.
Heath

I have one year and 12,500 added 2 quarts with Amsoil 15-40 and filter and will have a change on tue. Truck starts better and seems to warm up faster in the winter.

I will be changing over to Mobil ! turbo diesel 5-40 this weekend at 4,000 miles, I've changed the oil once already at 1,800 miles with Penzoil CJ-4 15-40 dino.

I always like to get a few thousad miles on them before I go over to synthetic.

Well I started to change my oil, drained the old oil and took the filter off, put the new filter on and poured a gallon and a half of Mobil-1 5-40 turbo diesel synthetic in when I read the label and saw that it was only CI-4 plus rated, so I had to drain it out [at $22.25 a gallon] and refill with the pennzoil 15-40 dino oil that I use in my big trucks because it's CJ-4 rated.


Stooopid.

I thought the Mobil was CJ-4

.and It Is Cj-4 Rated For My Lmm
You might want to check that.

Well I started to change my oil, drained the old oil and took the filter off, put the new filter on and poured a gallon and a half of Mobil-1 5-40 turbo diesel synthetic in when I read the label and saw that it was only CI-4 plus rated, so I had to drain it out [at $22.25 a gallon] and refill with the pennzoil 15-40 dino oil that I use in my big trucks because it's CJ-4 rated.


Stooopid.

I thought the Mobil was CJ-4

You're not stupid, it's the damn emissions requirements. My '07 LBZ also requires CJ-4 compliant oil. I used Valvoline 15w40 Premium Blue CJ-4 oil for the first 1500 miles, then switched to the Amsoil DEO 5w40 Premium Diesel CJ-4 oil. I've used the Amsoil DEO Premium ever since. I also prefer to put about 1500 miles on the engine before switching...just a habit.

I have used Mobile 1 almost since it came out. Love it. It is possible there are some containers of Mobile 1 that are older. I have two bottles in my garage that do not have the CJ4 marking. Just the brand new gallons I just bought are marked CJ4. It looks like it is just a label issue between older containers and new ones. My guess.

I don't think it can be just a label, there where different needs before ULSD and DPFs. [I think the biggest difference is the sulfated ash content]
I'll just use the Delvac and the Amsoil 15-40 in the other diesels I have.
[I have a 2005 Ford Excursion with a Powerstroke, a motorhome with a 2005 Cummins ISL 400 and seven class-8 Mack dump trucks, four with Mack E-tech engines and three with Cummins ISX 565 engines].
Thte oil won't go to waste.

i got 165000km on my truck i was wonderning if it was ok to switch to synthedic? i have ran it in all my gassers but im not sure about diesels... amsoil all the way

If you have no oil leaks now and have serviced well throughout, you should have no problem. What happens on high mile vehicles where the history isn't know, a badly maintained engine can develop leaks if sludge is what is sealing some holes. The syn. cleans it out and removes the plugs.:)
Otherwise if you it has a good history, there should be no problems.

My '07 LBZ also requires CJ-4 compliant oil.

LBZ can use CI-4 or CJ-4 per the diesel supplement manual. CJ-4 is a must if you have an LMM because of the DPF.

LBZ can use CI-4 or CJ-4 per the diesel supplement manual. CJ-4 is a must if you have an LMM because of the DPF.

For the rest of the country, that is true, but my '07 LBZ has all of the California emissions, and requires the API CJ-4 compliant engine oil.

I have been burning oil after my motor rebuild. I just switched to 5-40 mobile 1 full synthetic. Now I am hearing that synthetic is WORSE for motors that are burning oil? any truth to this? Should i go back to dino?

If it is truly burning it slipping past the rings, then yes, generally a syn will burn more. It slips past a little easier:(