I use shell rotella t 15-40. I was told this was a good oil for my dmax or any diesel. Is anyone else using this? I was not very excited about dumping "shell" oil in it. Any thoughts on mobil 1 synthethic?  

wait, i thought you were the all knowing individual that said this site was just the "blind leading the blind" and that we all knew nothing, called us all posers and such, so why are you asking for help or advice now on at least 2 threads???  seem to me that you really dont know what youre talking about now doesnt it  

Rotella has been a premier oil for diesel engines for decades. In fact it has been Caterpillars choice for years. Thier new ULSD formula is getting rave reviews. Mobil One Synthetic has released an oil specifically for diesels. It is a 5/40 and they call it "Turbo Diesel Truck". So far not so easy to find. AutoZone is the only one in my neighborhood that carries it. The best analogy that sums up the difference between dinosaur oil and man-made is at the molecular level. Consider both synthetic and fossil oil molecules as round marbles. Fossil formed molecules are not perfect, meaning they come naturally in varying sizes. Using marbles again as an explanation, some are “boulders” medium size and some are “pee-wee’s,” all are round and very slippery. Synthetic molecules, being man-made, are all exactly the same size, which means no one molecule carries more of the load than the next. This is why “oil shear” is greatly reduced with synthetic. Another analogy would be the difference between an asphalt road verses a cement road, both are smooth but one is more uniform. Heat is also a major cause of oil degradation. Here again synthetic far exceeds fossil in thermal-breakdown.  

duramark that is an awesome analogy. thanks for the great post!!!  

Hey Dbitch we have already had a thread like this so lets not start another.  

HOW ABOUT THIS DON'T GIVE THE OIL IND. ANYMORE MONEY BUY SOMETHING THAT IS MADE RIGHT HERE IN THE US, LIKE AMSOIL BECOME A PREFERRED CUSTOMER AND GET IT SHIPPED TO YOUR HOUSE.  

yea i always use rotella 5w-30 use 5w-40 if it wammer were you are  

LIVE IN MICH.  

i use john deere 15-40 synthetic.  i know it sounds funny but i read an article which lead me to talking to a couple diesel enthusist who said they know lots of people who prefer it above anything else?  

I didn't know Deere even had their own oil? I wonder if they actually manufacture it themselves, or have it supplied to them by a 3rd party?  

Ya we run in it in all our farm machinary too, so we buy it in bulk.  John Deere does manufacture it, i looked it up.  Any suggestions on oil filters, i just run the AC delco's right now, they're decent but im thinking after market.