62 MPH rule? What is the reasoning behind it?

When our trucks got whacked from 65 down to 62 all that was changed was the top speed. The trucks were speced for 65 from the factory. It's been a while now and they have produced the numbers that show we have save a little bit of fuel across the entire system.

We use more fuel running I80 across Pa since the trucks were cut. I'm sure they do better across the toll roads and central IL but we a shifting more in the hilly areas. If the loss of productivity was measured not even figuring in the trucks pull worse, we are loosing a 1/2 hour per night on a typical 500 mile run, which we run thousands of per day/night. I would bet that would be worth more than a very slight gain in overall fuel economy.

Now all we hear about is going green. I believe it is called the Smartway initiative or something like that. I tend to believe it now has more to do with this than actual production or fuel economy. One thing I do not know that I would like to, is if there is any tax incentive for "going green".

 

They do teach progressive shifting, and my wife and I use it religiously.

 

I can tell you that dropping from 77 mph gov. to 67 mph gov. I have picked up 1 mpg. avg.

 

One MPG is pretty significant, if it is accurate. But you need to factor in the lost productivity, since your hours on the road are now reduced. And I get tired if I have to drive slowly.