2018 389?

Talk to this guy.

 

I have a 16 with 500/1850 cummins. 2 axle reefer mostly 78 to 80k. Average 5.5-6.0 mpg (us gallons 3.785L/g). Recently had governor reprogrammed, now will run 85 mph. Driving with foot and keeping boost lower even with higher speed makes a big difference. I have 3.73 rear end with 18 double over and 11r22.5 tires. 1500 at 65 1600 at 70 1700 at 75. I will run it above 1500 but I only use maybe 40% throttle above that. It is a good truck and motor, so far, I only have about 180,000 km on it so far. Idled 1 night only so far. No emissions issues to speak of yet. I am a believer that idling is the fastest way to cause emission problems. I run Canada and don't usually get far enough south where it is too hot. A bunk heater for cold nights.

 

You pull 44k and still be under 80k with your 389?

 

If I play the fuel game, yes. 44k is about the absolute maximum.
I am 37000 full of fuel and def and reefer full. Truck has 225 gal reefer 75 gal and def is 20 (I think). My issue is steer weight. I can get to 11500-11600 at the most. Sleeper is 78" truck has 244" wheelbase. I make it work for me. Only a handful of loads exceed 42500.

 

This is the exact info that I've been wondering about. Thanks! The short wheelbase does it. The long wheel base 389's can weigh quite a bit.