A 30W oil will destroy your rockers very quickly, I know one of the top end jobs I did was a guy that was using 0W30 oil and the races were pushed down into the rockers and there was wear on the entire intake side and obvious wear on the exhaust side as well.

Shell Rotella T6 5w-40 is good and inexpensive (comparatively).

Mobil 1 TDT 5w-40 is good.

Mobil 1 0w-40 is good.

There are a couple other companies that make a Full-SAPS oil and that specialize in "synthetic" oils, although the North American definition of "synthetic" leaves much to be desired, alas I digress.

You're probably looking at a top end job, possibly a turbo as well, they don't like 30W oil either.

Also, as Garrett doesn't allow rebuilding of these turbos, you should not either. It's new, previously-owned, or nothing.

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Silver 2006 KJ 2.8L CRD Limited:
GDE ECO Tune / Fumoto Valve / E-Tecno GX3123 7v Glow Plugs / 2nd Gen Fuel Head / Mishimoto RED Hoses / Rockers/Lifters @ 114k / Hayden FC + 11 Blade Nylon / Sears P1 Battery / Transgo 45RFE-HD2 Reprogramming Kit / Timken Front Bearings

I'm sure she doesn't—Jeep is garaged at home. I've never been a real believer in idling down the turbo, but I'm more of a tdi/Cummins B-series geek and just haven't seen it make a difference there.

Hexus—I hear you about new only on the turbos. This is mostly a theoretical question at this point, but wouldn't the benefits of 40w be offset somewhat by the cold running conditions up here? And another theoretical; any mod or alternative turbos been tried and proven on the VM 2.8?

The only proven alternative turbo that I know of is the GDE Stage II turbo and it requires an upgraded (Euro or SunCoast) torque converter in addition to the GDE Stage II turbo flash which is discounted in price if you already have a GDE tune.

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs

It may be more that Mobil 0W-30 is primarily a gasoline motor oil. Looking up the specs on this says it does meet a CF spec but CF has been obsolete for quite some time. A diesel oil with a minimum CI-4 diesel rating should be used. This spec was introduced in 2002 to meet 2004 exhaust emission standards. Here is a description for the CI-2 spec published by the API:

"Introduced in 2002. For high-speed, four-stroke engines designed to meet 2004 exhaust emission standards implemented in 2002. CI-4 oils are formulated to sustain engine durability where exhaust gas recirculation (EGR) is used and are intended for use with diesel fuels ranging in sulfur content up to 0.5% weight. Can be used in place of CD, CE, CF-4, CG-4, and CH-4 oils. Some CI-4 oils may also qualify for the CI-4 PLUS designation."

I don't know why Chrysler would say an API CF is acceptable for an EGR equipped diesel!!

My choice is a CI-4 5W-30 and has been since I purchased the Liberty in 2007. 103K on the clock now with original turbo, rockers, and she runs great. Yes, the timing belt and associated parts were change at 100K.

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2011 Ram 2500 6.7L Cummins Deleted w/MiniMaxx G56 HDD 5W-30 & Bypass Oil Filter
2005 Liberty CRD Limited (Cracked Block) Sold
2015 Cherokee Latitude 3.2L V6 (Replaced CRD)
1992 Dodge Stealth RT Twin Turbo Pearl White/Black Leather
2008 Kubota GR2110 Diesel
2006 Key West 186 Sportsman w/135HP Honda OB
1943 Farmall H Restored

The oil may be the wrong type and not have the detergents to hold up the soot but lets look at the real problem. 10K and 20K oil change intervals! This is ridiculous. I would not do this unless the vehicle has a by-pass or centrifuge filtering system. 5K should be the longest between an oil change. It's not even $50 to do an oil change. Why wait this long?