Duramax Diesel

I have recently purchased a 2500HD 4x4 with the Duramax Diesel & a 6sp tranny.
A recent post asked about synthetic oil. I personally recommend Red
Line. You can see their products at http://www.redlineoil.com/ I use their synthetic engine oil, transmission oil, differential oil, transfer case oil, etc. The oil is expensive. I generally get it for $6.95 to $7.95/quart. Red Line recommends using the factory lubes for the first cycle to facilitate break-in & then change to the synthetics.
Red Line will tell you that you will get better fuel economy with their synthetics. This is true, at least for me. While I found no mileage improvement using a synthetic in the engine, I do get 2mpg better using the synthetics in the trans, transfer case, & differentials.
I have used Red Line synthetics in my cars (sports cars) as well. I have noticed the same mileage increase using the synthetics in the transmission & diff.
My opinion on oil changes: I believe oil changes should be done when the oil has sufficiently deteriorated in quality. I believe there is no benefit to changing more often than the manufacturer recommends unless the oil has worn out. The question remains how to determine this? Does the oil life indicator in the truck help? In my cars, at least, I find I can double the manufacturer's recommended oil change interval without the oil deteriorating in quality if I use the Red Line synthetics. I still change the filter on schedule, but I double the oil change interval itself. You may argue with this, but what's the problem if the oil is still of sufficient quality to allow this?
Now, I'd sure appreciate some advice:
Where is the best rpm to drive at for best fuel economy?
Admittedly, I am a first time buyer of a Duramax with a 6sp. Where would you recommend shifting to the next higher gear for a no-load condition & for a heavily loaded condition?
When I use the engine heater, can it be left plugged in all night long, or would you recommend plugging it in 2 hours before I leave for work in the morning?
Dave
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I admittedly am not completely Diesel savvy...But I have never used or heard of a better oil for diesels than Rotella. As much as diesels use oil, I have to wonder if synthetic will get used more because of its wicking properties. Any opinions or experience on this???

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On Fri, 5 Nov 2004 06:27:43 -0600, "Shades" <shades_1970(at)netins(dot)net> wrote:

My buddy works for an oil distributer and like a lot of trades, speaks his own language when it comes to oil, so I'll try to remember our discussions..
His main vehicle is a 2001 ferd 250 with the diesel.... he turned 100,000 miles on it a few months ago... says that he's always used synthetic in it, in the engine, tranny and rear end.. (2wd)
Anyway, every 3,000 miles, he takes an oil sample into work and has it tested... when it no longer tests within "acceptable limits", he changes oil & filter...
He averages about 12,000 miles between changes, each change gets a new Mobile One filter... he said that if most of his mileage was towing, he might need to add a quart between changes, but not very often...
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Does anyone sell a simple oil test kit/machine? that would be close to home-user friendly?..how exactly do you test oil?
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You decide if it's time to test it. Remove the plug and let it all come out, put new oil in and feel better about the cheap insurance..... (reinstall the drain plug first)
GMC Gremlin

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xeonpro wrote:

This might be a step in the right direction.
http://shopping.netsuite.com/dingo
go to www.google.com, and do a search for "oil analysis" or "automotive oil analysis" or what ever variation you can think of, there are sites out there.
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Thanks, Ill try it out.
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