Oil for 2009 Duramax Diesel

[jcmseven]

I purchased a GMC 2500 truck with the 6.6L Duramax diesel in May. To this point, I have had the truck serviced at the dealer, because the service manager is super bright and careful with it. The dealer is also quite competitive on the oil and filter change with a private place and do a thorough inspection each time also. My truck has about 15,000 miles on it already (I drive a lot) and is coming due for its next oil change. My question: is there any advantage in my truck going to synthetic v. a mineral based oil and if so, which brands should I consider?? Currently I am running standard 15w-40 Rotella, which was recommended by the dealer and which he uses in his own truck. He does not use synthetic in his truck, either. I have run Rotella in my Ford diesels over the years and it has served me well. I have not had trouble but have generally traded either right before or right after 100,000 miles. I also would welcome any input about oil filters, is the GM filter the one I should use or should I look at an aftermarket brand?? I have always been one to stick with the factory filter, even if I waffle a bit on the oil. I should also note the obvious, any oil recommended is supposed to meet CJ-4 standard, which the Rotella does for low ash.

John M

 

[Raw Dodge]

Yes theres an advantage! Mainly cold starting ease,which isnt a huge issue in NC,but it still wiil start easier.Fuel economy will be slightly better,esp if the truck has a lot of short trips or cold starts.The biggest issue,IMO,is the improved ability of the oil to withstand high temps,evertime you shut the truck off when tis fulyl warmed up,your turbo bearings are very hot,conventional oil cannot take the heat like a synthetic,and it can and will cause the turbo to fail earlier than if you used synthetic.If you let it cool down for a few minutes everytime beofre you shutdown,it isnt an issue,but who does that?Esp towing it is important.
I wouldnt switch to synthetic yet,put a few more miles on it,seat the rings,and then change over at your next oil change after you've got 20K plus on it.

 

[RalphVa]

The main advantage for synthetic is protection of your upper valve train. Sun oil did a study on a taxicab fleet, some with dino oil and others with Mobil 1. The ones with Mobil 1 had NO upper valve wear. This explains how synthetic gives 3 to 4% economy and hp increase, because hp isn't being used to grind away the valve train hardware.

The Sun Oil study mirrors one done by Exxon's Imperial Research where they started a K car with 4 cylinder engine having a transparent valve cover in a -40 degree cold room with various oils. The ONLY oil that did not produce valve train smoking was a 0wxx one. 0wxx can generally only be produced with a synthetic.

Generally, 0w20 is good for gas engines and is what is recommended for Ford Focus, for instance, and 0w30 is good for diesels and is what the local Mercedes dealers puts in its customer's diesel engines.

0w30 is what I use in all my engines, 2 diesels.

Ralph

 

[20 20]

ICurrently I am running standard 15w-40 Rotella, which was recommended by the dealer and which he uses in his own truck. He does not use synthetic in his truck, either. I have run Rotella in my Ford diesels over the years and it has served me well. I have not had trouble

John M

I've also been running rotella for years with no troubles. Why fix what isn't broke? I don't dislike synthetic but still have my doubts, if it's so great why can't it be used during break in period? I'll probably be spanked for not saying run with synthetic but I can see were modern tech is taking us........ to the land of throw away, instead of built to last. Merle Haggard said/sang it best " wish a ford and chevy was still built to last 10 years like they should!"

 

[Patches]

I've also been running rotella for years with no troubles. Why fix what isn't broke? I don't dislike synthetic but still have my doubts, if it's so great why can't it be used during break in period? I'll probably be spanked for not saying run with synthetic but I can see were modern tech is taking us........ to the land of throw away, instead of built to last. Merle Haggard said/sang it best " wish a ford and chevy was still built to last 10 years like they should!"

Actually, many high-end cars come from the factory with synthetic in the crankcase; Corvette, Porche, AMG, Mercedes and some others I can't immediately remember(senior moment). I used to believe the myth that rings wouldn't seat using synthetic oils, but, it is just that; a myth. I realize these examples aren't diesel, but the break-in issue is the same. However, I still run the petroleum oil that comes in my, less than high-end, new vehicle a 1000/1500 miles before draining and going to synthetic

 

[jcmseven]

Thanks for the posts so far. 20/20, you sound like my dad (which is not a bad thing). He says why spend additional bucks on something that will offer such little benefit in regular driving?? This sentiment is echoed by the service manager at my dealership. My slant is to eak out every last drop of mileage and performance I legally can do from my truck. Since they essentially cannot be modified without voiding the warranty and/ or damaging the DPF, I look for reduced friction as a performance and longevity enhancer. To most a 1% difference is no difference, to me, if it is a true 1% difference it would be worth it--especially if it enhances my longevity and reduces wear. I do wonder if I could stretch out my oil changes to every 7500 miles instead of every 5000 as I currently do given that I generally run the motor for at least 45 minutes steady every time it is started. If I could do that and get a bit better fuel economy it would make it worth it in my mind. Which oil does everyone recommend or is there a consensus here?? I know Rotella is 5w-40 for its synthetic. I have heard some people say they do not like Rotella Synthetic but I have never heard why. I know that despite claims that it is not up to some other oils, a large percentage of over road truckers seem to use it without difficulty.

John M

 

[Diamondpilot]

I do 5K oil changes in all my diesels. I do heavy towing on a weekly basis. When I switched over to synthetic we went to 7.5K changes. I do the same maintenance interval for my neighbors 2007 Dmax. If you are not doing any towing I would go 10K with synthetic.

By the way my new Nissan Titan came from the factory with Valvoline Synthetic. I have continued to use it changing the oil every 4K but would go 5K or more if I was not towing 7-8K with it on a weekly basis.

Chris

 

[RalphVa]

The oil change interval for VW TDIs is 10k miles or once/year. They use synthetic.

Figure out the economics of getting 4% higher mpg and changing once/year or 10k miles vs. 3-5k miles with a dino oil. Think you'll find out that synthetics pay out, and it's a heck of a lot more convenient to change once/year vs. 2 to 3 times/year. Less used oil to take to the auto supply store to dump, etc. In addition, your engine will last longer.

Ralph

 

[20 20]

RalphVa; I understand everything your saying except "your engine will last longer." Is there solid 100% proof of this? The guy that keeps up with the dino oil changes VS the guy with synthetic oil changes same type car in the exact same driving conditions{all most impossible to do}. Synthetic may be a better choice but is there 100% proof of it actually making an engine last longer?

I believe synthetic was made to cut down on oil changes but still get the benifits of dino oil{which =more changes}. If synthetic were to be so perfect then why bother even making dino oil anymore?

 

[WH401]

RalphVa; I understand everything your saying except "your engine will last longer." Is there solid 100% proof of this? The guy that keeps up with the dino oil changes VS the guy with synthetic oil changes same type car in the exact same driving conditions{all most impossible to do}. Synthetic may be a better choice but is there 100% proof of it actually making an engine last longer?

I believe synthetic was made to cut down on oil changes but still get the benifits of dino oil{which =more changes}. If synthetic were to be so perfect then why bother even making dino oil anymore?

If you start a diesel in 0 degree weather with a regular dino 15w-40 in the crankcase than your going to cause accelerated wear and tear on the engine because of the length of time it takes for a dino 15w-40 to flow. If you run a synthetic 15 or 5w40 in it's place than it will flow much faster, and produce oil pressure much quicker, there by decreasing the wear and tear on the engine. Synthetic oil by nature is slipperier and has a much lower cold pour point, add all that together and anything that's mechanical that requires lubrication will last longer.

"Why don't they just go to producing synthetic?", you say. Even though synthetic tends to cost more, but the length of time you can run it out weighs the cost, 90% of people are still fixated on the whole "3k mile oil change" thing. It's what they've grown up with and what they believe in and it's make the oil companies big money, so who would they be to upset that balance?