We tried one a few years ago, 2006 KW T600, 470 hp, 10 sp, 3.70 ratio. 610,000 miles. Pulling 97,000 lbs. Didn't get 500 miles and oil cooler filled rad with oil. $3600 bill. 1000 miles later, 1st turbo tried falling off. Could have been shops fault. 4000 miles, radiator opened up. That and charge-air, $4000. So now we are 4000 miles in, have spent $7600, truck is making 3 to 3.75 mpg. So, we take it to Fargo and have them run it on the dyno. $1200 later, Cat says engine is running and pulling perfectly. At 9000 miles, I notice a small loss of oil pressure. Found some loads to get me to Bismarck to have it checked. New bypass valves, new filter base, new oil pump, down the road $3200. 1000 miles (TWO DAYS!!!!) later, I was losing oil pressure again. Pulled into Dickinson, had called ahead and had Butler set me an oil filter and wrench outside the door, bought a $22 gal of oil at truck stop and changed filter in the parking lot. Had pressure back. Was supposed to load in morning, said hell with it and drove home empty. That weekend we bought the first 9900 with N14.
So, after advertising for a couple weeks, found someone from SD to buy the truck, he didn't even get 30 miles and called asking why truck didn't put out heat. We ended up paying $750 for a new water pump, he paid for labor. Found out a few months later the guy had a head gasket put in within a month, and within two had finally given up and had it overhauled.
In 10,000 miles, between fuel and repairs, we went backwards by about $5000. Also, before anyone asks, I was the only driver, I tried driving it everyway to Sunday. 53 mph, 55 mph, 58mph, driving in 9th gear, nothing worked. One trip I had to bounce 375 miles. Made 3.9. Most awful experience with a truck I believe you could ever imagine, and this truck only had 600,000 miles.
