Have an 01 and pull a 12000 lb. diesel fishing boat. Going from Scramento to San Francisco there's a hill called Red Top. My old 92 dodge used to get a hernia pulling the hill, about 30 mpg, stock. The new truck, with 2500 miles on it pulled the same at 40. Better, BUT. Added an EZ two weeks ago, pulled the boat Sat. , same everything, in fact had more fuel aboard, about 100 gals in boat, at 50. It was out of OD naturally, letting the cruise handle it, ands for kicks floored it, but the cruise already had it floored. So, it pulled that hill a LOT better, so I'm happy. I feel after I get a few thou. on the engine, it will get even better.