Thanks Jim.

[DickWells]

I just read your article on oil in the Feature Articles. A good read.
I've used Baldwin filters any time I could get my hands on them, ever since I read Dr. Lee's write-up on his filter testing, back a few years. I think they'r great, and have no plans to use anything else. Is there any particular reason why you personally use AC's?
Also, I kind of like your comment on changing oil when you can't see through it on the dipstick. Now, I installed an Amsoil bypass filtration system last summer, while home in VT. Filled with Rotella 5-40 Syn. With about 7K on it at this time, the color is like light honny. If it was you, would you still feel confident in waiting for the color, or would you try to get a sample tested? While I have no intention of waiting for it to get to the point that I can't see through it, I'm wondering how essential lab testing is for a by-pass system, especially this first go-around.
Thanks.
Dick Wells

[More Power]

I just read your article on oil in the Feature Articles. A good read.
I've used Baldwin filters any time I could get my hands on them, ever since I read Dr. Lee's write-up on his filter testing, back a few years. I think they'r great, and have no plans to use anything else. Is there any particular reason why you personally use AC's?
Also, I kind of like your comment on changing oil when you can't see through it on the dipstick. Now, I installed an Amsoil bypass filtration system last summer, while home in VT. Filled with Rotella 5-40 Syn. With about 7K on it at this time, the color is like light honny. If it was you, would you still feel confident in waiting for the color, or would you try to get a sample tested? While I have no intention of waiting for it to get to the point that I can't see through it, I'm wondering how essential lab testing is for a by-pass system, especially this first go-around.
Thanks.
Dick Wells

Thanks Dick,

AC filters also tested pretty well in Dr. Lee's test, and they are easily obtainable here in MT. That's why I use them. I buy oil filters by the dozen so I always have one when I need it.

Like you discovered, the Duramax burns a lot cleaner than the 6.5 does. However, those who run a smoky power module or do a lot of heavy towing will see more soot buildup in their oil. Soot is usually the reason to change the oil. If yours is staying cleaner longer with additional oil filtration, have it tested at about 7500 miles, to see whether there's any other problem with the oil (i.e. coolant, fuel, metals, etc.).

After you've had your oil tested a time or two, you'll get a better feel for how often you might need to have it tested and how long you can really run it. Eventually, you might be able to get by without testing - but that's entirely up to you. :)

Jim

[Mark Rinker]

I am so jealous. Not since my 2002 with Kennedy's tune have I seen a Duramax that keeps the engine oil honey colored for more than a trip around the block.

My two 2006 LBZs both make black oil in short order, I attribute that to the effect of the EGR system, mostly.

Maybe Kennedy's latest economy custom +40hp will do the trick, it arrived here recently and will be tested starting next week's roadtrip.

I'd sure like to see oil that clean again, and I know with the right tune, the engine can clean up on its own - thats what the 2002 did after only a few changes, and that was at 150-170K miles!!!

[Kennedy]

Would you believe I went a full 12k on my 2007 last change? Just a standard Baldwin oil filter with a Filtermag on it for the ferrous junk. Oil was darkening, but nowhere near as dark as my 2002 turns it. Oil was Delvac 1 of course. I've run much longer drain intervals with this truck than normal. Part due to laziness, but mostly because I can see that everything is looking good. It just burns that clean.

Also had 21k on fuel filter (don't try this at home) and it tested fine for restriction, BUT bear in mind this truck (and my others) fuels almost exclusively from my own tank which is double filtered before leaving the nozzle.

[More Power]

I should point out that if you're dealing with a picky dealer, you should service the engine according to the schedule printed in your owner's manual, and have receipts to prove it. Extended drain intervals or using fluids not specified in your owner's manual can complicate warranty coverage.

However, if you know a good service manager, ask him for his opinion regarding extended drain intervals when using additional filtration. A reasonable manager will likely agree with you about running the oil longer, but getting that discussion out of the way can make things easier.

Jim

[DickWells]

Thanks for the come-backs.
Mark, I can see no rhyme or reason to this dirty oil business. My 04 LB7 has consistently run clean for 5-6000 miles, even before the by-pass. Always with a Baldwin filter, of course. The old Suburban will go 1500 - 2000 before it starts to get dark, with the same oil and filter.
Now, a guy here in the park has an 09 Silverado that colors the oil quite rapidly, but doesn't use a drop in 5 K miles. His 07 was the same. Late 07 W/DPF. Lemon. His 04 Chevy went 5-6K without darkening much. He likes Rotella better than I do. I'm using Rotella 5-40 synthetic right now, and I think I've had to add a quart back a ways at maybe 4K? Does it (Rotella) really cook off? I used to think that Castrol Syntek 15-40 Blend was really good stuff, and would buy it now if I could.
An Amsoil rep at a local fairground RV show told me that Castrol and Rotella Synthetics weren't real synthetics! Who to believe? He was an Amsoil Rep, after all! If and when I change next time, I'm going to try Mobil synthetic.
Going to pull a sample as soon as I get near a testing facility.
Thanks, everybody.
Dick :)

[JohnC]

Castrol and Shell start with mineral base stock and "process" it into a "synthetic" base stock. Amsoil starts with "artificial" base stock. (Secret sauce?)

Different strokes...

[rustyk]

"Synthetics" can come from a variety of base stocks, including natural gas, LPG, and mineral oil. The result has to be a new homogeneous base stock with no impurities; how it gets there is of no consequence. Because the new base stock is uniform, prediction of the performance of additives such as viscosity index (VI) improvers is more accurate, but research has enabled results in mineral base stock to be close to that of synthetics.

What tends to be overlooked in the synthetic/mineral oil discussions is the reason engine oil is changed: Depletion of the additive package. When contaminants in motor oils exhaust the additives designed to neutralize them, the oil is overdue for change. The base stock, synthetic or mineral, is probably in excellent condition, but the oil is done.

When the additive package is exhausted, contaminants can cause deterioration of the base stock, and synthetics can hold out a bit longer than mineral, but by then, it's too late...

Because there are other contaminants besides soot, there is only one thing that can be determined from the color: Color. And color is not an indicator of anything, except color.

[DickWells]

Ahah. So, now I need to get my oil tested. I think I understand a little better now, what old Jerry Rivers was trying to convey, way back in the late 70s, when he used to shake his head and say, "Who do they think they're fooling, with all this talk about synthetic oil? How can it be synthetic, when it all starts by coming out of the ground? It's still mineral oil, regardless." Well, seems he was both right and wrong. He's long gone, now. Wonder if he ever read an explanation like your's?
Thanks.
Dick:)
PS: Wish he was still here, as well as many others who I had the privilege of knowing. Most of them WW2 Vets. Bet most of TDP members have similar thoughts, eh?