I often get various questions in regards to my fuel mileage numbers. People comment that 10 mpg is nice with a loaded GVW between 60,000-65,000 lbs. Often times this comment is followed by the question “how is your fuel mileage when you travel into the mountains pulling a heavier load?” I decided to answer that question this week when I had shipments that took me from the Carolinas to Michigan. The exact route was from Cleveland, NC to Brighton, MI. The highways used were: US 70, I-77, US 33, I 270, US 23, I 75, US 23 and I 96. While on I 96, I drove 36 miles with an empty trailer to pick up a load in Redford, MI to be delivered in Troutman, NC. The return route was I 96, I 275, I 75, US 23, I 270, US 33 and I 77. The particular routes take you over Fancy Gap on I 77 and through the heart of West Virginia. Also included were many miles of US routes. I am scheduled to make two of these round trips this week.
As of this post, I have completed one of the trips mentioned above. Here are the details of the trip. I loaded a 34,000 lb. shipment into the trailer in Cleveland, NC and set out for Brighton, MI. I was hoping for a heavier load however this shipment was all that they had available. When I reached the top of Fancy Gap on I 77, my dashboard readout indicated 7.9 mpg. As I continued the route, the mileage began to steadily rise after Charleston, WV. When the dashboard readout was checked again in North Baltimore, OH, it read 8.9 mpg. The last hour leading up to North Baltimore included a harsh crosswind along with downpours. After having some dinner, I continued my way towards Brighton, MI. As I parked the truck for the night, the dash registered 9.2 mpg.
In the morning, I departed with my empty trailer for the 36 mile trek to Redford, MI. An interesting side note while pulling the empty trailer on the 36 mile jaunt to Redford was a fuel mileage readout which proudly displayed 14.2 mpg. As they loaded the 44,000 lbs. of freight into the trailer, I mused to myself that the 14.2 mpg won’t last for long. I departed on I 96 and traveled down I 275 to I 75. A little below Findlay, OH on I 75, I checked to see how the 14.2 mpg average was holding up. As expected, it had dropped considerably to 10.1 mpg. As I traveled across US 23, I encountered a bit of a traffic jam due to construction. Upon arriving in Columbus, OH, the dash indicated 9.8 mpg. Continuing along this journey, the mpg readout continued to decline as I traveled through the Appalachian Mountains in West Virginia and Virginia. At the top of Fancy Gap, the dash readout was 8.6 mpg. The final 60 miles on this trip has you losing elevation and therefore it was no surprise when the fuel mileage began to rise again. Upon arriving in Troutman, NC for the night, the readout at the end of the day was 8.9 mpg.
In summary, the Detroit DD15 400 HP/1750 FPT down sped engine. The DT12 transmission equipped with a 2.16 axle ratio performed admirably on this trip. Climbing ability (which is always in question with a 2.16 axle ratio) was more than adequate. For the most part, my speed never dropped below 45 mph as I climbed the various mountain paths unless another vehicle slowed me down first. The descent control function of the DT12 combined with the compression brakes on the DD15 managed my downhill speed flawlessly. When the speed limit would allow, I set the cruise at 65 mph and in the 70 mph sections, I set IPM at 5 mph over speed and 4 mph under speed. The northbound leg of the trip had a GVW of approx. 68,000 lbs. and the southbound leg had approximately 78,000 lbs. I was pleased with 9.2 mpg heading north and 8.9 mpg heading south. As of this writing, I am leaving for Brighton, MI once again with a GVW of approx. 70,000 lbs.
I look forward to reporting the results from this week along with the actual figures from the fuel pump. Also of note, the dashboard readout has been within the same tenth on average.