NE North Dakota - 4/23/2026 15:24

Have a 2016 Freightliner Cascadia that pulls a tandem axle 41' Timpte trailer. Truck has an ISX 15 Cummins set at 450hp and 1550ft lbs 10 spd eaton 3.55 rears. Honestly its kinda a dog, hauling winter weights of 88-90K will pull out on the highway and put my foot on the floor and it takes several miles for it to get up to 65mph. If there is any headwind or slight uphill it can barely hold 65.
Asked cummins and they pulled the build sheet for the engine and truck and the highest they will set it with the injectors it has is 475hp and 1650ft lb so I could get an additional 25hp and 100ft lb for $600. I'm more than willing to spend the money, but my question is will I even be able to tell a difference? doesn't seem like much of an increase percentage wise.
Have a friend that works at a Freightliner dealer and he said they turn up the Detroits from 435 to 450 all the time and the drivers love it. I just have a hard time believing I will be able to tell.