Anyone know of any other additional bonus of going to full synthetic fluids.I have found better mileage about 2 more mpg,now I'm getting better milage than a guy who got a 6.0rotflhes getting 10 mpg I'm getting 12/14 .I know the temp range is lowered and less wear and tear and more forgiving of going over on oil changes. Also anyone trying the mobil oils offer longer change intervals I'm not to sure I would trust this in anything doing any real work or real hard driving.
I own a 2003 6.0L and get about 21 mpg highway, 17 mpg city and 14 mpg towing my Vette while using AMSOIL Series 3000 Synthetic 5w30 Heavy Duty Diesel Oil. AMSOIL rates this oil for 15,000 miles/1 year in severe duty. I took my last change to about 10,000 miles.
Amsoil blows Mobile out of the water. Amsoil is good for 25K on a single oil change when equipped with a Nanofiber media filter like the EAO's or Donoldson Endurance line. Under severs service it is 15K like Subdriver mentioned. I think it's silly to NOT go longer on a change with any synthetic.
AMSOIL does recommend 25k miles/1 year change intervals for that oil in normal service, but most of our trucks see what is normally defined as severe service. For severe service, as I mentioned, they rate this oil for 15k miles/1 year which is the same interval as the new line of AMSOIL Ea Oil Filters. If 25k miles scares you, how about 409k miles? 409,000 Mile Oil Drain Interval Mack Truck Teardown
No, I'm not kidding at all. Welcome to the world of synthetics.waytogo Like stated, it depends if you are putting the vehicle through normal or severe service.