Hi,guys!Which (AMSOIL) oil is best for my 6.0,5W-40 or 15W-40?And what is difference between these two?Thanks a lot for replay.

 

The 5w and 15w indicate what the weight of the oil is in winter weather and the 40 indicates the weight of the oil when it warms up. Depending on your climate some say use 5w-40 and some say 15w-40 and yet some dealers say 10w-30. I've been using 15w-40 in mine and have had no issues. A lot of it has to due with personal preference I think. Do a search and read some of the comments and choose what you feel is the best for your truck is my best recommendation.

 

I've used synthetic 5-40 since the 2nd oil change.....I'm in Maryland, so we get pretty hot in summer and a little cold in winter.....it's been good for me. I get mine at Wally World...use Rotella....lots of us here do!