Hope to be driving a KW soon

I am glad that I found this and this thread about IH trucks and Maxxforce engines. I and another driver will be getting a new truck in about 6 months and the company I work for lets the driver spec the truck. They have been buying mostly Freightliners, but do have 3 Prostars. Even though they aren't having any issues to speak of yet, I have been hearing bad things about them from other sources. I currently am driving a Coronado that another driver spec'ed (I replaced him when his back gave out 1 1/2 years ago), and other than a recurring a/c condenser problem that me and the other driver with a Coronado had for a while, it has been a really good truck. We both have 300,000 miles and wiring harness/ecu problems are starting to show up now.

I was an o/o for 14 years and put 1 million miles on a 97 KW. I bought it with 350,000 miles, sold it with 1,400,000 miles and it still had the original trans, rears, kingpins, u-joints, etc. The Series 60 engine wasn't even burning any oil yet when it broke a wrist pin at 1,000,000 miles. I had Detroit do a 3rd level overhaul, which basically replaces everything but the block. It is still going strong for a neighbor that I sold it to using it for local work.

I had talked with my supervisor a few months ago about my experience with my KW and the great service from the dealership. Although he has talked with that dealership before, he has been staying with Freightliners with Detroit engines for the last few years for a few different reasons. Recently, he has been thinking about looking at other options, including switching to Cummins.

Since he will be buying trucks soon, I spoke with the KW salesman and learned he had the spec sheet for some T660's that a flatbed company nearby just recently bought as well as the spec sheet for a T660 they had on their lot. I told my supervisor what I found and he asked me to get the specs and other info so he could look at it first and then talk to the salesman.
I have my fingers, toes, and eyes crossed. Hopefully, I will be spec'ing a new KW in a few months.

Although I really did like the Detroit in my '97, I have not had any complaints with the Cats and Cummins I have driven, so a Cummins suits me just fine. Although I don't pay for the fuel, mpg is still a concern for me. Better milage means less fuel stops. Whether I am getting a KW or FL, I am thinking about getting a Cummins in the 485 to 550 hp range. I would like to hear some mpg's from anyone with one of these engines, especially the 550 hp/2050 lb-ft torque.

 

That chart was in the info that the KW salesman gave me. One of the big factors in fuel mileage is how the driver actually drives the truck. Most big trucking companies these days buy trucks that try to take out as much of the driver part of the equation as possible to make up for the brain dead idiots they hire including auto transmissions and engines with the smart torque settings. For many years I have been driving for fuel mileage, which includes using low rpm, easy takeoffs and using cruise whenever possible.

Theoretically, a standard engine should get the same mileage as an ST engine if driven properly. I will drive for mileage most of the time, but I want the power there if I need it. I was thinking like you that the 485 would probably be better on fuel, but I would still like to hear from someone with a 550 that drives for fuel economy. There are several O/O's that can get 7 mpg or close to it with there 700+ hp (pre-emission) engines built by Pittsburgh Power.