In this installment, I would like to address a question that comes often when having a discussion about my Cascadia AeroX powered by the Detroit Integrated PowerTrain. My Cascadia is powered by the Detroit DD15 400 HP /1750 FPT @ 975 RPM through the DT12 direct drive AMT transmission and put to the ground with a 2.16 rear axle ratio with active lube management. The first question most people ask me is “how does it pull in the mountains” or “how does it do in the hills”.
My reply is always the same as I do not spend that much time going uphill. It is, however, a fair question as to how well a truck pulls or does not pull, is the most memorable part of any given trip. My reply is, “my truck does not pull a hill as well as a truck with more horsepower or a lower gear ratio.” I then share that the last time I looked, most of our country is flat and where it's not flat, half of that is downhill.
I personally like to build my truck much the same way you would build a race car. On the race track, you don't build the car to only be proficient at being the best at any one part of the race track, or you will come up with shortcomings on the rest of the track. The winning formula on the race track is to average everything out so you excel the entire way around the track. Everything becomes a compromise in order to win the race at hand.
There are many other things that go into “winning” the race, such as having room to adjust to changing conditions such as track temperature, moisture content if it's a dirt track, and so much more. Another factor is to find every advantage over your competition within the confines of the rulebook.
When picking the components that will make up the truck you plan on earning your living with is much like building a winning race car in most ways. It is not a good idea to build the truck all-around any one part of your operation. This is where I will get back to the question of “how my truck pulls going uphill.” I am willing to sacrifice quite a bit of uphill speed to be able to do better on fuel or to have a rear axle ratio that can cruise at higher speeds when necessary. My 2.16 rear axle ration has worked out to be very beneficial in obtaining maximum fuel mileage at cruising speeds of 65 mph and still is able to do very well on fuel at higher speeds as demonstrated in Project 70+/10.
Another thing to consider is what kind of terrain and weather conditions will you be operating the truck in. If you will be always on the highway with very little time in the snow, a 6X2 axle configuration may be a “winning” setup as it offers better fuel mileage through less parasitic drag. The increase in fuel mileage from a 6X2 axle configuration comes from only using one differential to move the truck forward while the other axle in the tandem axle assembly simply rolls along like a trailer axle. I compare this to the same difference as it would be to drive with the engine fan on all day in terms of efficiency. The 6X2 also comes with a weight saving in the neighborhood of 400 LBS if you have an operation that could benefit from a lower tare weight.
Picking the right tires also plays a critical part in winning the race. Pay attention to getting the tires with the lowest rolling resistance while making sure they offer enough traction to traverse the terrain you expect to encounter on a regular basis. Wide base single tires are a great way to lower rolling resistance while also lowering the truck's tare weight. If your truck spends a lot of time delivering off-road to job sites you may want to lean toward a high traction tire instead of a fuel-efficient tire because it does not matter how good your truck does on fuel if it can't deliver the goods.
I have done blogs on this subject in the past which you may find interesting so here are some links below. Remember the race is not won on the “one hill'!
I hope this blog helps you to win the race to the highest profits.