GOVERNED AT 65 mph

That is a different discussion entirely and a decision each truck owner (or maybe the carrier) must make for themselves. One thing is certain.....you will save fuel by slowing down.

 

Well if you're saving fuel drving slower, you're on the road longer and that's more weight longer.


And RPM's play a factor in mpg not speed. And think about it when you hit a hill with low rpms you're using more fuel to pull opposed to having more momentum..

 

That all depends on where your torque is made. What rpm. My engine gets max torque at 1100 rpm so I can lug it down and still use minimal fuel while having max pulling force to climb the hill.

 

It's all a trade off, and there are so many variables that the blanket statement "you save fuel by going slower" is in many cases a significant oversimplification.

My FFE company truck, a 2012 Prostar, MaxxForce 13 set to 430/1450/62mph got a monthly average of 6.4mpg, hauling food grade tank around the northeast. Average cruise 60mph, forgot what rpm. 10spd with 3.55 rears.

My truck, a 2004 Western Star Lowmax, Series 60 set to 515/1650, no governor, gets a monthly average of 6.25, hauling reefer. Average cruise is 65@1425rpm. 13spd with 3.58 rears.


One, aero truck at lower speeds with a trailer that completely disappears behind it, the other as aero as a barn with a 53' reefer sticking up over the mid roof. There's something other than merely speed differential at work here. One ought to be getting significantly higher mileage but isn't. Why? My hunch is a whole lot more time spent at full "throttle", like when encountering grades or headwinds. That 5mph difference in momentum has to count for something.

Just throwing fuel on the fire. Feel free to tell me I'm nuts

 

Incorrect. From about 55 to 60 MPH, you burn half your fuel to propel the vehicle, and the other half to overcome wind resistance. As you increase your speed beyond that, the percentage of fuel you use to overcome wind resistance increases.

 

Well ima tell u how speed saves me...I dont have to pay a professional shrink 200 dollars a hour to try to heal me from talking to myself because im driving 60....or depression....lol thats how it saves me

 

A day earlier with just a 3 mph difference? Doesn't fit the math... Skip down to Scenario 2 to see what I mean.

http://melpor.hubpages.com/hub/Do-Driving-Faster-Really-Save-Time

 

Don't know if that's directed at me, but I'm not arguing that point with you. As stated before, that is its own discussion, and ultimately comes down to what each owner feels is the right thing to do. If you get it done in a manner which works for you, rock on.

 

A 3 mph difference would only be 30 miles extra in 10 hours of driving. So yeah the math don't add up. Unless the other driver was stopping every 2 hours to talk at a truckstop or grab something to eat maybe.

 

That's a good read. But most likely over the heads of a lot of people.