I'm coming up on 15,000 miles and another engine oil change. I towed the last 6000 miles with 5,000 to 14,000 pounds through all types of conditions (hot deserts, mountains). The oil is looking pretty dirty and I want to switch to amsoil. At what mileage should I switch to a full class 4 synthetic? I've heard that it is reccommended to "break in" the engine first to set the rings and whatever else prior to running synthetic oils. Just wondering what some of you have done and when you started running synthetic engine oils.

 

Go look at #23; thats what www.cummins says:
http://www.cummins.com/na/pages/en/p.../faq/index.cfm

I went to syn @ 18k. I'd say go for it.

 

Deerenut I'd also say go for it. With that much heavy towing you've been doing, your engine is broken in.

 

Go for it ;D ;D ;D
I've been running AMSOIL since day 1. I don't worry about breakin periods
If it ain't broke in by the first oil change I don't care, it'll break in one day
Do it now before you've scored up the pistons and rings too bad.

 

I have 5k and am switching to syn, Delvac 1. It's starting to get cold and I can't bear to here that Cummins start with maple syrup in it's crankcase.

So my truck takes longer to break in 8)

Ron W.

 

cummins doesnt recomend synthetic until 20K. but they do say that if you strap a heavy trailer to the truck right away it shortens break in period.

 

[quote author=DF5152 link=board=20;threadid=22974;start=0#msg215548 date=1070111114]
cummins doesnt recomend synthetic until 20K. but they do say that if you strap a heavy trailer to the truck right away it shortens break in period.
[/quote]

Thats not necessarily true. I thought the same thing as well. Looks like u can now go to synthetic after the first oil change. Go figure. If I remember right, when synthetics first started to appear, Cummins was altogether against them, doesnt seem that way any longer....

http://www.cummins.com/na/pages/en/c...4A0004AC33EA57

Mobile Delvac 1, is probably one of the best (if not the best) oil money can buy.

 

[quote author=Dr. Evil link=board=20;threadid=22974;start=0#msg215585 date=1070120027]
[quote author=DF5152 link=board=20;threadid=22974;start=0#msg215548 date=1070111114]
cummins doesnt recomend synthetic until 20K. but they do say that if you strap a heavy trailer to the truck right away it shortens break in period.
[/quote]

Thats not necessarily true. I thought the same thing as well. Looks like u can now go to synthetic after the first oil change. Go figure. If I remember right, when synthetics first started to appear, Cummins was altogether agaist them, doesnt seem that way any longer....

http://www.cummins.com/na/pages/en/c...4A0004AC33EA57

Mobile Delvac 1, is probably one of the best (if not the best) oil money can buy.
[/quote]

there is nothing at ur link ???

 

Weird.....no idea why is doesnt work.....seems the URL is too long.

Anyway, go to:

Cummins.com
Customer Assistance (far right side of page)
FAQ
fourth topic down....

**********************************************
Pasted directly from the Cummins.com site:

" Can I use synthetic oil?

Synthetic oils can be used in all Cummins engines, beginning with your second oil change, as long as they meet Cummins guidelines. The only time Cummins recommends not using synthetic oil is during the engine break-in period on a new or newly rebuilt engine. For the first oil change in a new or newly rebuilt engine, Cummins recommends the use of a petroleum-based oil. Cummins recommends that you use a quality multi-viscosity oil that meets or exceeds Cummins Engineering Standard (CES) 20071, 20072 or API CH-4 specification, like Valvoline's?Premium Blue?and Premium Blue?2000. API CG-4 or CF-4 oils are also allowed at reduced oil drain intervals. In addition to the above requirements, Cummins B and C Series engines are equipped with sliding cam tappets which require lubricants meeting category SG, SH or SJ for superior protection of the sliding followers when CG-4 or CF-4 oils are used. For regions where oils meeting the above specifications are not readily available, select a lubricant which meets CES 20075 for use in Cummins B and C Series engines. Choosing the proper lubricant for your application will maximize your drain interval and extend the life of your engine. Consult your Operations and Maintenance Manual for drain interval guidelines appropriate for your specific application and oil selection. "

**********************************************

 

The link works fine, you just have to copy and paste the entire link in the url window. Clicking it only accesses the underlined portion, which is incomplete.

 

hmmm......that was too early in the A.M.

 

what retail locations sell the delvac 1

 

[quote author=DF5152 link=board=20;threadid=22974;start=0#msg215690 date=1070135536]
what retail locations sell the delvac 1
[/quote] That's the trouble, it's almost as difficult to obtain as Amsoil. Truck stops may carry it, as well as "fleet" type store chains. I've heard Wal-marts in Canada carry it, but not in the U.S. Your local Mobil jobber should have it.

I'll PM you an online source for Delvac 1. When I checked prices including shipping, it was less expensive to buy this at retail, than what I could purchase Amsoil S3K 5W-30 for at preferred customer, or wholesale price.

 

my wal-mart here sells the delvac 1

 

Most Walmarts in Canada sell it - but it is $35 CAD a gallon....ouch !!!!!!

Do you not have any Mobile bulk dealers? Id think that it would be cheapest to buy it in a 5 gallon pail at a bulk station or truck stop.