1 Census 2010 Race for Effingham County, Illinois. 2  Census 2010 Latino for Effingham County, Illinois. 3  Census 2000 Race for Effingham County, Illinois. 4  Census 2000 Latino for Effingham County, Illinois.  Illinois Voters for Effingham County, Illinois.
On average, a truck traveling at 65 mph instead of 75 mph will experience up to 27-percent improvement in fuel consumption. As a rule of thumb, for every one mile per hour increase in speed, there is a corresponding 0.14 mile-per-gallon (mpg) fuel consumption penalty, says Kedzie.
Speed is more critical on a diesel than a gas engine. On the highway, in the 50-75 mph range, the fuel economy will go down about 3 mpg for each 10 mph increase in speed. A gasoline engine will lose about 1-1/2 mpg for each 10 mph increase in speed.