i was in napa auto parts today and noticed they have a napa brand 15w-40 try it ? or stay away from it ? i have a 2002 ctd ext cab 4x4 auto 165,000 mi any segestions on oil and the weight of oil i should use?

 

I work at a Napa Auto Parts here in Texas. I can honestly say that people choose the napa brand more than Rotella, Dela, or Amsoil. Myself, I run amsoil in my truck. I haven't tried the 15-40w oil that we offer but most of my friends use it since it is cheaper than others because we arent really going through another company to get it.

 

go with the amsoil... diffs, tranny & t-case (if you have one).

has proven to net 1~1.25 mpg or so by several posters...

edit: oh yeah, I have it throughout and gained 1~1.5 mpg...

 

I also recommend Amsoil for your engine.

 

what weight ams oil should i use i have never used ams oil before in my ctd

 

For Amsoil in your 2002 Cummins you can use either CI-4+ or CJ-4 rated oil, so you have a few choices:

HDD Series 3000 5W-30 Synthetic Heavy Duty Diesel Oil http://www.amsoil.com/storefront/hdd.aspx

AME 15W-40 AMSOIL Synthetic Diesel & Marine Motor Oil http://www.amsoil.com/storefront/ame.aspx

DEO Synthetic 5W-40 Premium Diesel Oil (CJ-4) http://www.amsoil.com/StoreFront/deo.aspx

PCO Synthetic Blend 15W-40 Heavy Duty Motor Oil http://www.amsoil.com/storefront/pco.aspx

I run DEO because my 6.7L Cummins requires a CJ-4 low sulphur oil. If I had a 5.9L Cummins I would probably use AME because it has a TBN of 12 and should give the longest life. If you want to save money, or you're the kind of guy who changes his oil every 3,000 miles, the PCO is not a bad choice.

 

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