Stanadyne comes in at #8 in the Spicer Lubricity test. I use Opti-Lube XPD which is #2;

http://www.johnfjensen.com/Diesel_fu...itive_test.pdf

Sorry havent been able to get on the site for awhile.It does have over 100,000 miles and iam checking things out .Thanks to all of you for your information!!

Do you have a check engine light? You could have a cylinder contribution test performed, this would help with the diagnostics. I run TCW II two stroke oil in mine at 200:1 at the fifth tank full I run just Howes Fuel Treatment. It has been great and I am getting 16 mpg.

That's a great article, thanks for the link. Randy

That's a great article, thanks for the link.

One more thing, check for water in the fuel. The owners manual explains how to purge it. There should be a light on the dash if you have water.

I found it on a Cummins forum(I own a 2006 Dodge dually). I notice more engine noise and clatter when I don't use the Opti-Lube so those who think the additives in the new ULSD fuel are enough might want to try one of the top five or eight in this test. Lots of guys don't know about this test so I like to post it when I can.

Here's the link to Opti-Lube;

http://www.opti-lube.com/dfi.htm

Change fuel filter. Then drain bowl before putting lid on and fill with ATF replace lid and let run approx. 30 sec then shut off refill and let sit over night.

Glowplugs-do yourself a favor and replace them all. wouldnt hurt to replace the relay also at the same time.

you can use 2cycle oil also for addative.. 1oz per gallon. my old 7.3 had over 210k on it when i sold it and the guy that bought it said he never drove a 7.3 that ran so good. The DP tuner chip helped some too.