I wanted to share the updated current results from my Cascadia Evolution powered by the Detroit DD15 and DT12 transmission. I received this truck in October of 2012 and headed out on my first run just in time to drive through the tail end of hurricane “Sandy.” Since then, things have been running smoothly. I must say that I am thrilled with the performance of the Cascadia.
The Life-To-Date mileage is 158,702. The fuel mileage result as calculated on paper is 9.613. The engine report mileage per gallon came to 9.79, just a slightly higher difference from my paper calculation of .177. The Diesel Exhaust Fluid (DEF) came in at 359.97 miles per DEF gallon. From a maintenance standpoint, I’ve completed three 50,000 mile maintenance interval oil changes. Due to the oil level not moving much more than a quart, there has been no reason to add make up oil to this point.
My Cascadia is set up with the Detroit DT12 and is a 12 speed, automated manual transmission with shorter gear steps. The Detroit DT12 was designed with a number of innovative efficient features to achieve optimal fuel economy. My truck is equipped with optional Direct Drive which cuts parasitic gear mesh losses in top gear. eCoast helps maximize efficiency by allowing the vehicle to coast down grades. My eCoast percentage has varied depending on the month from 12% to 18%. For those of you not familiar with this feature it has been an important function in my being able to maximize efficiency. Another important feature is Skip Shifting. This feature helps increase acceleration to achieve cruising speed quickly and smoothly by skipping over unnecessary gears.
Another great contribution to my fuel efficiency is the Meritor FUELite 6x2 Tandem Axle with a 2.50 gear ratio. This feature maximizes fuel efficiency by powering only one of the two axles. Also, this 6x2 set up reduces the vehicle weight by 400 lbs.. To help with the traction deficit associated with only powering one axle, the truck is equipped with electronically controlled air suspension (ECAS). This system maximizes traction in a 6x2 axle configuration by automatically transferring weight through the air suspension without overloading any of the axles. In addition to ECAS, I also have a locking differential.
A question I get asked often is “do I ever get stuck with a 6x2?”. The answer is “yes”; two times I’ve actually been stuck in the last year. Both times it was my fault, as I put the truck into a situation beyond its capabilities. Once, I was bobtailing and pulled into soft grass and the other time I had parked on top of eight inches of hard packed snow. Both times, it just took a slight tug from a pickup truck to get me back moving again. Don’t get me wrong, one must be careful when operating a 6x2 axle equipped truck as you need to pay attention to the terrain and make sure you don’t “hang” the drive axle in a low spot. I often compare operating a 6x2 to trying to pull a 13ft 6in high trailer under a 12ft high bridge. You have to drive this set up for what it is. When driven 
properly, it helps achieve maximum fuel efficiency. I can add that it actually helps handling once you’re moving in the snow as power can never be applied to the rear rear axle. By not applying power to the rear rear axle, the tractor doesn’t try to kick out as easily on turns in the snow.
Here are the rest of the contributors towards this awesome performance review of Freightliner’s Cascadia Evolution: Fleet Engineers, Side Skirts, NoseCone, ATD Dynamics, Trailer Tail, Real Wheels Wheel Covers and FlowBelow.
