Looking for oil recommendation. Here's what I've got:

2002 Duramax (common rail, no EGR, no DPF)
low speeds, low loads
Illinois weather (-10 to 100F with few exceptions)
ULSD fuel, with a bit of bio at the Shell station I usually use
15-20k miles per year

I want to take real good care of it for a long, long time. I want to teach my kids to drive stick in this truck, and the oldest is 2 :)
I'd be happy to pay more for an oil that delivers improved fuel economy (especially for our winters), longer intervals, and better protection.

I don't particularly want to pay more just to get oil that's compatible with emissions stuff I don't have (like EGR and DPF) unless it's also giving me something I do value.

Any suggestions? I'm using Rotella 5W40 at the moment. I work at Cat and have a dealer near my house. They do UOA for only $11, so I plan on doing them periodically for a while to set my intervals, then maybe just at the changes.

Not really use your fuel additives as needed, stay on top of air and fuel filtration and water draining etc.....Diesels are generally designed with long life to start with. Out side of OEM design issues most often failure is linked to lack of maintenance since GM got rid of the 6.5 and their louse standayne pump issues with the Duramax.

You might look into a nice commercial bypass filtration system designed for diesels that is about the best you could hope for to do anything special!

Oh I would change all your gear lubes and ATF out at 10,000 miles! I would either use Amsoil ATF designed for the Alyson or Castrol Syntorque etc........Change both transmission filters and call it good for the next 50K miles!

oh I should add that Delvac-1 ATF is also good stuff if you can find it!

I didn't mention other lubes here, since this is the engine oil part of the forum. But since you (JohnBrowning) mentioned it, other lubes were just changed out as follows:

axles = M1 75W90
xfer case = Valvoline syn DexVI
transmission = Allison transysn (note, it's a ZF manual, not an allison, but the owner's book says transynd is ok)

I didn't do any UOA on these. Front axle had some goop I didn't like, but others looked reasonably clean to my untrained eye.

I did both axles one day, and the rest switched to synthetic a couple weeks later. Sure felt slicker and smoother after that (or was that the placebo effect?)

You won't be able to get away from the oils that are made to accomodate a CAT and DPF. That's because most of the engines being made need the CJ-4 oils. You will benefit from reduced soot loadings due to the improvements in the injection system. The TBN attrition will be slower because of the small amounts of sulfur left in the fuel. It depends on how you are about keeping track of things. You would do very well with a warm weather 15W40 dino oil and normal OCI'S. For cold weather, use a 10W-30 or 10W-40. If you just want to run one oil year 'round, synthetic is the way to go. It'll just cost you more to go that way. With a 5W40 synthetic, you'd be safe IMO to extend your OCI's by half.

Given your goals, I'd begin a steady diet of a premium 5-40, change it twice a year, spring and fall. Begin teaching the kids how to change the oil at around age 5, by 10 or 12 depending on their apptitude they will be able to handle it themselves

Welcome to the site!

I, too, am in the midwest and have a Dmax (2006).

I would suggest, because of your annual mileage and location, perhaps a 10w-30 HDEO in winter and a 15w-40 in summer. Change twice per year. This will give good protection, with minimal cost.

Since you're not towing anything heavy, you'd be just fine. The Dmax engines are some of the very best wearing diesels in the light-duty truck market.

Check out my UOA in the diesel UOA section; I think you'll be impressed.

My 2 year old already helps me in the garage whenever we get the chance. She can carry quart bottles, hand me tools (though I can't just ask her for a 17mm deep well and expect to get the right thing), and is great at wiping off the end of a dipstick.

Occasional used-oil testing may give you a warning about coolant or fuel contamination, and help you determine the optimal oil change interval (OCI). You're already using a good oil.