Community Forums

Busa Dave · 07-19-2014, 08:14 AM

Am looking at several coach's that have the big Cummins. In all of my small diesel engines the last 30 years I have used the AMSOIL Premium 5W-40 Synthetic Diesel Oil (15-40 before) and would like to know if anyone else uses this. For me peace of mind is worth the cost never having a engine problem in the past.

May be a discussed topic in the past but I could not find any detailed threads.

TurtleKent · 07-19-2014, 09:21 AM

I would verify with Cummins that use of Amsoil will not void the Cummins warranty.

FlyingDiver · 07-19-2014, 11:00 AM

The ISX15 uses 12 GALLONS of oil for an oil change. The ISX engines are pretty bullet-proof, and I think $500 just for the oil would be overkill.

Steve Ownby · 07-19-2014, 11:22 AM

Quote:

Originally Posted by FlyingDiver

The ISX15 uses 12 GALLONS of oil for an oil change. The ISX engines are pretty bullet-proof, and I think $500 just for the oil would be overkill.

I'm a believer in synthetic when there is a clear advantage. The problem with synthetic oil for heavy duty diesels is that the manufacturers do not allow an extended drain interval for synthetics. Diesels produce so much soot for the oil to keep in suspension that a good CJ4 oil like the popular Rotella T 15-40 does just as well as the synthetic. With a capacity of 12 gallons plus a $50 filter, unless it's accomplishing something, I vote for Dino oil.

Steve Ownby
Full time since '07

Busa Dave · 07-19-2014, 12:34 PM

Steve--agreed however the PAO oils have better shear protection as well as many other properties. Yes it will be expensive but only use the PAO oils in all of my vehicles. I gave up Dino completely on all vehicles including gas about 20 years ago.

Regarding Cummins----the oil I use is not approved and have used it in some pretty expensive engines albeit none as expensive as this. This is not a concern for me.

Route 66 · 07-19-2014, 12:38 PM

If Cummins doesn't require synthetic oil, I wouldn't use it and I didn't in my ISL. Motorhome diesels are not heavy duty use.

As long as the engine is under warranty I would do exactly as they recommend to avoid any warranty problems.

Busa Dave · 07-19-2014, 12:51 PM

Ok maybe I need to rephrase --- anyone use the oil I asked about? I understand and use PAO oils period. The environment I operate in will exceed 115 ambient in the summer.

Warranty issues are not a concern. The ISX is a HD engine...

Coma · 07-19-2014, 01:12 PM

Quote:

Originally Posted by Steve Ownby

I'm a believer in synthetic when there is a clear advantage. The problem with synthetic oil for heavy duty diesels is that the manufacturers do not allow an extended drain interval for synthetics. Diesels produce so much soot for the oil to keep in suspension that a good CJ4 oil like the popular Rotella T 15-40 does just as well as the synthetic. With a capacity of 12 gallons plus a $50 filter, unless it's accomplishing something, I vote for Dino oil.

Steve Ownby
Full time since '07

Agreed. Where ultra low -20 or below temperatures require it for starting or if oil temperatures frequently range above ~230F to prevent coking.

FlyingDiver · 07-19-2014, 01:42 PM

Quote:

Originally Posted by Route 66

If Cummins doesn't require synthetic oil, I wouldn't use it and I didn't in my ISL. Motorhome diesels are not heavy duty use.

As long as the engine is under warranty I would do exactly as they recommend to avoid any warranty problems.

I would never use a non-approved oil while the engine is still covered by warranty. That's just asking for trouble.

Cat320 · 07-20-2014, 12:46 PM

Quote:

Originally Posted by FlyingDiver

I would never use a non-approved oil while the engine is still covered by warranty. That's just asking for trouble.

Same here.

MartinP · 07-20-2014, 03:05 PM

I called up Cummins they neither approve or disapprove synthetic oils. All they say is make sure it meets their specification which AMS oil does. I run the 15W40 AMS Oil synthetic in my HM. FYI have always run synthetics in cars ( Mobil 1), motorcycle(AMS Oil) and semi synthetic (Exxon Elite and Aeroshell) in my airplane powered by Lycoming. I wont go back to dino as I am happy with synthetics.
Martin

Koop · 07-25-2014, 06:42 PM

Quote:

Originally Posted by Busa Dave

Steve--agreed however the PAO oils have better shear protection as well as many other properties. Yes it will be expensive but only use the PAO oils in all of my vehicles. I gave up Dino completely on all vehicles including gas about 20 years ago.

Regarding Cummins----the oil I use is not approved and have used it in some pretty expensive engines albeit none as expensive as this. This is not a concern for me.

Busa Dave, I'm a loyal Amsoil user of many years. However, in my ISL I use dino (Shell Rotella). If I remember correctly, Amsoil isn't pure PAO. It's a proprietary blend of synthetic polyalphaolefin (PAO) base stock and synthetic ester base stock. This is what makes their oil superior.

I used it for years in my race bikes and it's still the only oil I'll put into gasoline engines.

Busa Dave · 07-26-2014, 07:14 AM

Quote:

Originally Posted by Koop

Busa Dave, I'm a loyal Amsoil user of many years. However, in my ISL I use dino (Shell Rotella). If I remember correctly, Amsoil isn't pure PAO. It's a proprietary blend of synthetic polyalphaolefin (PAO) base stock and synthetic ester base stock. This is what makes their oil superior.

I used it for years in my race bikes and it's still the only oil I'll put into gasoline engines.

You have a good point. The PAO content is dependent on the line of oil you use inside the Amsoil brand itself. I used Rotella exclusively in my oil burners until about 1988. For Dino that is good stuff.

R2Home · 07-26-2014, 09:46 AM

I know that a lot of people like and use Shell oils and there is nothing wrong there. I have used Delo 400 oils for many years and for me see no reason to change. In my oil 5.9 I switched to synthetic many years a go. It got driven a lot so I was on an 'extended' change on it. New oil was installed, at 5000 miles the filter got changed and oil was topped off. At 10,000 miles the oil and filter were changed. That engine has over 235,000 miles on it. On my other two diesel engines the oil gets changed more often. The 6.7, every 7500 miles and the 8.9 once a year, regard less of miles traveled. There are several 'good' oils out there and as long as they meet engine specs, they should be good to go.