gonzo, to each their own, i have been a mech for 5 years, trained extensively, before that diesels where a passion and hobby for me, i have spent countless hours reading and studying vehicals, bumper to bumper. i live, breath, eat, sleep, and bleed automotive. i also am currently studying for a b. a. in mechanical engineering. with that said, yes you are right ANY oil that is api rated for the engine when changed properly and with quality filters will make the cummins last a long time. i think cummins speced this engine for 4 or 500k miles but i cant remember.
however synthetics do handle more heat and shear less which means better lubrication. personally i have experienced significant positive changes using schaeffers full synthetic over the delo 400 i used before. based on oil samples i cant also run the oil longer between oil changes, the last thing is i picked up fuel mileage, about 1 to 1. 5 mpg. at 10k miles thats a difference of 37 gallons of fuel, at 4. 00 a gallon thats 148 dollars savings. an oil change costs me just under 100 dollars including tax, using schaeffer oil. the dello 400 cost me just over 50 dollars including tax, however i had to change it at 5000 miles. thats 2 50 dollar oil changes on delo to every one schaeffers, so that part is a wash. the high molly content of the schaeffers is a big bonus to me, since moly sticks to everything and is almost as slippery as teflon, i have better cold starts and i also have better protection under high load conditions. this is just the engine oil, i could go into the rest of the oils needed in our trucks. i have been running this truck with schaeffer lube for the past 40 or 60k miles now (id have to look in my records to really know for sure) in all i personally have put on nearly 100k miles in the last 4 years, and unless something major happen to me or the truck, i plan to run it as my daily driver for at least another 4 years and longer if i am allowed to keep it and keep driving it. that will be almost 200k miles that i put on the truck, thats on top of the 150k miles on the truck when i bought it. i hope to roll 1,000,000 miles thats twice the amount the engine was rated for (10000 hrs x 50mph average = 500000 miles) in this truck, and the only work i want to do in that time is to make it go faster, with as little repair work as possible.
again gonzo, to each their own. delo 400 vs valvoline premium blue va rotella t vs castrol etc. all conventionals they are going to measure nearly the same. same with synthetic from the major manufacturers. however there are smaller companies that just like in any industry make a slightly to significantly better product then the major players in the field. personally i think schaeffers tops them all, others on this forum like their own favorite small private label, and maybe it works just as well, maybe it works better, i dont know, i havent tried them. i have found an oil i like that i think makes a big difference in the way my truck runs, i have run the costs and i think i come out ahead with it. if case ih works for you then run it, the only thing that ever upsets me about people and their trucks is when they dont take care of it. thats when i get grumpy.
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