6.7 Fuel Mileage
First let me kindly say this. I respectfully don't care what Ram guys or GM guys are getting for fuel mileage. I don't have that truck so it does not pertain to me. They are great trucks but I don't o...
Forum Discussion
N-Trouble wrote:
Mileage between truck A and truck B off the same lot configured exactly the same can vary greatly. For instance I have seen numerous stories of ownwers who upgraded from 2011-2014 Dmax trucks to the new 2015(same powertrain) only to see significant differences in mileage in either direction. Same driver, same fuel stations, same loads, etc. Only thing that changed is the truck itself. Yes they are all built on the same line to the same specs but some just get better mileage than others.
That would probably be due to the speedometer bell curve. What a lot of people don't know is that the speedometer on these trucks (or any vehicle for the matter) are not exact from the factory because even things like tire inflation can throw off accuracy depending on how the speed is measured.
I don't know exactly what the tolerances of the bell curve are. I remember reading an article from Fox News a few years ago where Dan Edmunds, automotive engineer from Edmunds.com, state that speedometers cannot have an error of more than 5% by automotive standards. Basically it can be more than 2.5% up or down from the actual speed. This means at 60 mph, it is perfectly acceptable for a speedometer to read 1.5 mph more or less. The difference gets greater the faster you go. It also means that two of the same vehicles can have a 3 mph difference between them when both vehicles speedometers read 60 mph. The odometer would also be affected since the method that it counts miles is from the same sensor.
So if a person gets in a truck that reads 1.5 mph more than actual then it will show him getting better fuel mileage than actual. On the opposite side of the bell curve, if a vehicle is going 1.5 mph slower than what it actually is then it will seem like it is getting worse fuel mileage than actual. This could explain the difference in mileage between two of the same trucks, and how some are able to gets a little better fuel mileage while most everyone else that has the same truck does not.
Although as I said earlier that the driving style of the driver and speed is the biggest factor in fuel mileage.
