I have a new goal I have been working on. This goal has come from the interest of where my fuel mileage would be if I drove faster than 65. This brings me back to a goal I had years ago to achieve a mile per pint of fuel consumed. If you do the math on a mile to a pint it comes out to eight miles per gallon. Since then the bar has been raised to consistently achieve above ten miles to the gallon fill-ups at 65 mph.
On my current truck it has been able to achieve 13.4 mpg with a cruise speed of 58 and a low of 8.8 at 74K and a cruise speed of 75 mph. During this time of higher speed driving I have been able to break the 10 mpg mark with cruise speeds of up to 70 mph. All these factors together have led me to a new goal which is to achieve 10 mpg at 70 mph with my 2018 Cascadia Aero X known as New Blue.
For the first month of testing my average mpg has been 9.647 at 70+ mph as compared to a lifetime average of 10.02 mpg at 65 mph. During this time cruise speeds as high as 75 mph have been utilized where legal and appropriate to do so.
For information sake lets figure out the difference in costs for these increased speeds.
My average fuel cost has been 2.519 at 10677 miles for the past month of testing.
10.02 MPG lifetime average of truck my fuel cost for this past month would have been $2,787.95 with an average fuel price of 2.519.
At 9.647 MPG at my increased speed my fuel cost came in at $2,864.17
For an increased cost of $103.78
The benefit to me was that I shaved 14 hours off of my normal trip from Laredo to Charlotte. You say 14 hours off is a lot! Typically, it takes me 2.25 days of driving time. I was able to do this run in two days. In all honesty I only had ten minutes of driving time left when I arrived in Charlotte. With that precious little time left to drive this scenario would not work out on a regular basis, even the slightest traffic jam would have made me have to use hours of a third day of driving. A large portion of these 14 hours savings came from skipping over the additional ten-hour mandatory rest period.
This month’s fuel mileage average ended up only .373 lower than my life time mpg average.
The difference of .373 would make a bigger cost difference if the initial mileage figure was lower. I once did a blog on this subject by clicking on the highlighted area “One tenth at a time”. https://www.teamrunsmart.com/articles/truck-smart/september-2012/one-tenth-at-a-time
Keep in mind all of these results were with the latest in technology with the Cascadia Aero X my aero trailer and your results may vary greatly.