In my first CNG day cab, it was easy to settle up on the idea of switching over to the cheaper alternative fuel of choice, since diesel was somewhere in the realm of $4.00 per gallon here in California. When diesel prices began their descent to where they now sit, hovering somewhere around $2.75 per gallon in the Golden State, it was around the same time I was considering trying out my second truck in this CNG journey of mine. One would have thought with the new truck being larger and having a sleeper, that I would have seen a decrease in fuel economy, but my last quarter fuel results gave me a little bit of a shock!
Monitoring my fuel results is something I do quite closely, since part of what I do is talk about the viability of alternative fuels in the heavy-duty trucking industry. When I looked over my most recent quarter’s fuel usage on my current truck and compared it to the last full quarter’s fuel numbers from my old truck before I turned it back in, I was shocked to see that the new truck had better fuel efficiency numbers. With a slightly longer wheelbase and a sleeper, one would typically think it would have worse numbers than the day cab I was sporting before.
The secret may lie in the fact that this truck has a different transmission than my previous truck. It was originally built with a manual 10-speed, but then up-fitted to an Eaton Ultrashift+ 10-speed AMT. With its skip-shifting capability, which does work on CNG engines as well (contrary to popular belief), it lends itself to being more efficient in the realm of fuel consumption. When I had the 6-speed in my other truck it was much quicker zipping around town, but the race I was most interested in winning was the one where fuel savings was the “finish line”!
Who would have thought that the small differences between my previous day cab and this sleeper model could have ended up in an average 1/2 mile per gallon gain in efficiency thus far? I will continue to monitor the difference in economy this winter as I continue trudging through the local SoCal traffic this winter and hopefully see even better fuel efficiency gains as I learn to mesh with the truck better!