I ran my experiment for a little over two weeks. After more than two weeks of driving a max of 70 on the highway and slower acceleration in an attempt to raise my gas mileage, I’ve got the results. The driving was a bit grueling at times, especially when the starting speed speed limit is 70 on the highway. I managed to do it for a little more than two weeks and finally filled up my gas tank a little before I ran it to the bottom. After all that I gained about 1 mpg. I guess I won’t be driving that slow anymore. Apparently it really depends on the vehicle. I imagine an SUV or truck would see a larger increase from slowing down due to the larger wind resistance. I drive a 2008 Accord V6, so I guess it’s somewhat aerodynamic.