i am thinking of changing from amsoil 15-40 to rottela 5-40 synthetic. i know that 15-40 is whats recommended but is 5-40 ok. and is there a hoots of a diffrence between the two. i will continue to run amsoil oil filters becouse all i can get around here is fram. thanks for the input. p.s. i know there has been a million amsoil battles. i am just looking for anwsers to my simple questions. thanks!

I have been running the Rotella Synthetic since 14000 miles with no complaints. I change about every 6500 miles and use it year round in chilly Vermont. No need to add between changes. Now at approx. 48K miles.

Vegas must have lots of parts places. NAPA, ADVANCE, O'Riellys, Autozone, Carquest are places to try. Mobil 1-303 is a top rated filter and a little pricey but I prefer them. Also consider Baldwin, Delco, Carguest, Napa Gold.There's others to.

my last oil change i went to Rotella 5w-40 synthetic. Very happy so far, about to change after 6000 miles in the next few days. oil is still brown.

I changed over to Rotella syn at 10000 miles. Very pleased with this stuff so far, 39000 miles. I change oil about 7000-7500miles. This part is hard to believe but also noticed slight lowering of temp. 2-3 degrees. Just towed from New Jersey to Calif. about 68-70 towing 9000lbs, never over 200. Im pleased, my 02

i have been using amsoil oil for about 50k. the reason i am going to stick with amsoil filters is the thay are a better made filter than fram and napa from what i have read. so i take it using 5-40 in 110+ degree temps is ok. or am i better staying with 15-40 rottela or 15-40 amsoil? or does it not make a hoots of a diffrence. i change my oil and filter about every 6-7k miles. thanks for the advise. i just dont want to make a mistake. i need this truck for another 150k more miles.

Ive been running rottela 15w40 with a oilguard bypass for 110000 miles,change the oil and filter between 7k and 9k change the oilguard every other change.Run oil samples every other change bottom end looks good.2004 lb7 4500 The bottom end of these moters are strong ,Thats the only good thing I can say. animal 4500 rvtransporter

One real difference between the two is that I believe the Rotella Synthetic is not a true synthetic....it is a "hydro-cracked" dino oil, which by virtue of some court ruling (originally involving Castrol?) may be labeled as synthetic. I also believe the Amsoil is a "true" synthetic...

That being said, I used Rotella Synthetic in mine until the Mobil 1 Truck & SUV formula came out. From what I understand it is repackaged Delvac 1 which I believe is a true synthetic. All are good oils....and probably some better than straight dino....but then again, many miles have been put on many trucks using the dino!!!