I wanted to give you a performance update on the Cascadia Evolution I with the Detroit DD15, 400 HP, 1750 fpt engine and Detroit DT12 AMT Transmission and the Detroit 6x2 rear axle with a 2.28 final drive ratio.
The story on this truck has been one of consistency over the last 72,341 miles. The fuel consumption while driving those miles has added up to 7,614.214 gallons for an average fuel mileage of 9.529. The fuel cost comes out to .21 cents per mile. My diesel exhaust fluid mileage is 346.5 mpg with a cost per mile of .008 cents per mile.
In comparing fuel mileage on this truck to my previous Cascadia evolution which had a Detroit DD15 455 HP/1550/1750 Multi Torque, Detroit DT12 AMT Transmission and a Meritor fuel – lite 6x2 rear axle assembly with a 2.50 final drive ratio. The previous truck combination had a lifetime fuel mileage average of 9.782 which is .253 mpg better than my current lifetime average with 42 fill ups to date.
Here is where the consistency comes in on the current truck… the highest fill up was 10.838 mpg and the lowest fuel mileage has been 8.503 mpg as compared to the old truck which had a high of 11.488 mpg and a low of 7.75 mpg. My current truck somewhat perplexes me as when I’m expecting to have a really bad fill up, it turns out better than expected. When I think I’m on a record breaking run, the mileage number doesn’t turn out as I would expect. The other factor which may be holding back fuel efficiency numbers of my current truck is that there is an increased demand for me to conduct demo rides for various truck sales associates. Of course, everyone wants to see how the new Down Sped Engine 228 rear axle ratio combination pulls on a grade. Needless to say, this effort doesn’t do much for my lifetime fuel mileage numbers. Over the time I’ve been driving the current truck, the majority of loads have kept the truck in the 60K-65K gvw range. Also, most of my shipments load/reload at the same docks. A typical week usually includes only 42 empty miles out of 2,860 miles driven. Other factors to consider are that most of the miles driven have been during the winter months.
Driving this new engine rear axle combination has been a very different experience than anything I’ve ever driven in the past. This is due to the down sped engine making its maximum torque output at a mere 975 rpm’s. In fact, nearly all the excitement in regards to power comes in at below 1200 rpm’s. and seldom do you ever find yourself in a situation where the rpm’s time above 1300 rpm’s. During my demonstration rides, drivers are always amazed at the tachometer only reading 900 rpm’s in twelfth gear. When the truck is asked to accelerate, the engine responds quietly, yet with great authority. Nobody can believe how it’s able to accelerate and remain its composure with such a low rpm. The engines in which most of us learned to drive with decades ago would have shuttered and shook in protest during these conditions. I’m also pleased to report that when in the mountains and climbing grades, this truck maintains a higher speed than my previous truck by a couple miles per hour. I was a bit doubtful on this current combination in the mountains however it has proved me wrong.
Another great feature on my current truck is the Detroit Intelligent Power Train Management System. This new technology reads the highway ahead while on cruise control and manages your momentum in the most efficient manner. It helps coordinate the use of such features as ECoast and available power from the engine. This system truly shines when you get into sections of the highway which include rolling hills. Intelligent Power Train Management System is a subject all its own and we can cover that in another blog in the future.
I am looking forward to the summer months ahead as the conditions for better fuel efficiency are greater. I will post and update to inform you how the truck performed during the warmer weather.