Just thumbing through the old owner's manual(08 1800 hpna viii) and after reading their recommended shift points I feel like an al-Qaeda member. 12,20,25,31 mph plus or minus. I drove truck since I was a kid and I could run a 750 hp cat with a 21 speed and not scratch a gear. I'm going to try it their way this evening and I may have to flog my own back while reading the manual aloud...cover to cover. WISH ME LUCK.