We have 2 kenworth t800s with ism's and we love them. 1 os a 2008 and 1 is 2010 both at 370 hp with 3.90 rears. We run them heavy and over hills everyday at 80,000 and they are holding up will. 2008 has abt 752k and 2010 around 680k. Haven't really troubled us much with emissions or regens eithere since their ran hard. Their light weight and get 6.5-7 mpgs. They highest you can turn them up is 425hp.