Oil for early 07 Duramax

[davtil]

What oil, regular or synthetic, and brand does every one use. I've been using Rotella I'm thinking of switching to Amsoil Synthetic for the Duramax. Input would be greatly appreciated.

Dave De Valk

[davtil]

What oil, regular or synthetic, and brand does every one use. I've been using Rotella I'm thinking of switching to Amsoil Synthetic for the Duramax. Input would be greatly appreciated.

Dave De Valk

[Ray,IN]

Shell Rotella 15W40, year-round.

[Hitchhiker]

I also use Shell Rotella 15w40, have used it in all my diesels since my first one back in the early 90's.

[brad03ca]

I use Castrol GTX 15W40, seems good to me..

[R.G.Wise]

I have offroad equipt. and class 8 trucks; and use Delo 400 15w40 in everything, including a Ford powerstroke and my Duramax. My pickups are changed and about 8000 mile, or earlier if the computor says it needs it.

[RVwheels]

AMSOIL good move!! Have used it since 1972 in everything. Now in my ILS400 for the last 4 years.

[Bagman57]

I run Amzoil series 3000 5 W 30 Heavy Duty Gas/Diesel oil in our GMC diesel cargo van and also in our MH with 8.1 Vortec (gas) engine. Works for me! Bagman57

[diandtom]

I use Shell Rotella 15-40W. I don't think it matters much any good diesel oil is ok. The engine will out last the body anyway

[KaseyKahneFan]

Get the best of Both Worlds. I use Shell Rotella Synthetic 5w-40. Shell synthetic is WAY cheaper than Amsoil.

[brad03ca]

So how often do you change the oil then?...

[diandtom]

I change oil and filter at 5K and fuel filter at 10K. I may go a another thousand on oil as the manual shows 12K.
Tom

[dnewton3]

Dave De Valk -

When considering your lube choices, you should review a lot more than just what sits on the shelves.

First, consider many things such as your operating conditions, your envirnoment, your loading, etc. Then, decide what service intervals you're interested in. Finally, choose your lube/filter package.

Synthetics are fantastic products, but msot people do not understand their benefits and limitations. Generally, synthetics offer greater service intervals. There are some other fringe benefits, but those are rarely ever capitolized upon by the average consumer. Often, the benefit of temperature extremes is touted, but unless you're doing cold sump starts in -25 deg F, that really does not matter. Same goes for extreme heat; any liquid cooled modern turbo-diesel has the ability to withstand it's OEM design criteria with conventional ("dino") oil.

During typical operation, a conventional oil will protect your engine just as well as a synthetic. Most people would disagree with this, but most people are also heavily influenced by marketing hype and mythology. Used Oil Analysis (UOAs) show that for "normal" operation, conventional oils protect every bit as well as syn's. That might be a bit hard to swallow for some folks, but the data is what speaks volumes above the rhetoric. I've seen literally hundreds upon hundreds of UOAs that reinforce this point.

I'm not saying that synthetics are a poor product or a waste; nothing could be further from the truth. What I'm saying is that to get the true benefits of using synthetics, you need to greatly extend your Oil Change Interval (OCI). If you cannot or will not do that, you are wasting money. Generally, synthetics cost approximately 3x more money over a quality dino oil (Delo LE, Delvac 1300, Rotella T3, etc). To get your money's worth, to get your ROI, you would need to extend your OCI 3x further. Typically, a Dmax is very easy on oil. It is not unheard of for a Dmax to be able to go 10k miles on conventional oil, and post excellent UOA results. That in mind, if you don't extend your OCI to 30k miles with the synthetic, you're wasting money.

Again, it's not a question of the capabilities of synthetics; it's a matter of your use of synthetics. It's very likely that the only way you'll recoup the costs is to extend your OCI, and if you can't keep your hand off the wrenches, it's not worth the expense.

[Cat320]

Quote:

Originally Posted by Hitchhiker I also use Shell Rotella 15w40, have used it in all my diesels since my first one back in the early 90's.

Same here..on my third diesel.

FYI...GM states in the owner's manual that the type oil used does not alter when it should be changed or change intervals.