698 mile run, so see reason for losing 450,000 mile 13 with new motor. Liked to burn fuel. 100 to 120 gals more per week than 16/17's before rebuild. Mileage went up 1.5 to 2.0 mpg in 16, same in 17. Added average of 20 mins drive time over 13 Cummins with hard cruise, 30 mins after the rebuild, still at Cummins break in period and got best fuel milage, only 1/2 mpg less than 16/17's. Rolling hills 1st 60 miles of run is 13 to 17 mins of the 20. Drop extra gear with both 16/17, sometimes 2. 2 of 4 16's we have/had were hard cruise, so they can be set that way. KCY shop said not allowed now, and will reset those who have it to floating cruise when doing spec. checks. Foot gets tired at times.