Here is a couple of reasons I use mobil one in both of my trucks. My R/T tows like a madman and has a very limited engine compartment with that 5.9L in it. Lots of heat! The other is the fact that I can run a thicker oil like 15w-50 in my R/T or 86 Ram D250 without the valves and lifter clattering for a few minutes like it did with regular 20w-50 or even 10w-40 oil made it do. I had to go all the way down to a 10w-30 and 5w-30 regular oil to stop the valve clatter when cold at start up even in summer. No way am I towing my quads with a huge engine at 70-75mph doing 2400 RPM's(3.92 gears) in the 100 degree heat down here for 250 miles round trip with a regular 5w-30 or 10w-30 oil. Now imagine your quad's job... one cylinder, idle to full out for extended times, mud, shock loading, 4wd, low speed airflow problems, and our big butts to tow around. Run a good syntetic blend at least. Spend the extra 4-5 dollars and buy a blend in 10w-40 or even 15w-40. good luck out there!

Dakota R/T