New Ram is awsome!
First road trip 2 weeks ago, sadly no camper yet, but was loaded up with RV parts from the Elkhart surplus stores! Had the cruise control set on 75 for most of the trip, LI to IN in about 10 hrs. ...
Forum Discussion
No, the computer does not know exactly how much fuel is used and it doesn't even know exactly how fast you are traveling due to varying tire pressure levels causing different tire diameters and other factors. The injectors only use the amount needed and dumps the rest back into the tank. There is no measure of exactly how much is used by each injector, only the time each injector opens/closes based on its fuel mapping. The computer mileage is just an algorithm.
I keep detailed records of almost every fill-up of all 8 vehicles I have owned for the past 15 years which ranged from two BMWs, a Ram 2500, F150 Ecoboost, F150 5.4, C6 Corvette, and a JK Jeep. I also recorded the computer mileage upon every fill-up. On tanks where there are very little stop/starts of the engine like the runs that TFL does in their tests, the computer is very close to calculated. On tanks where there are multiple stops/starts of the engine, it was off anywhere from 1-3 mph in every vehicles I have recorded. Generally, the more stops/starts of the engine the further off it was.
Also, the TFL loop does not use the mileage that each truck's computer says it has traveled. They use the actual distance of the trip, not the distance that the truck said it traveled. Not every vehicles speedo is 100% accurate and the standard for most manufacturers is a bell curve of about +/-3% the last I read. Tire wear and psi also effect the speedo which effects how many miles the vehicle's computer says it traveled which is what the ECM's mpg algorithm is based on.
I keep detailed records of almost every fill-up of all 8 vehicles I have owned for the past 15 years which ranged from two BMWs, a Ram 2500, F150 Ecoboost, F150 5.4, C6 Corvette, and a JK Jeep. I also recorded the computer mileage upon every fill-up. On tanks where there are very little stop/starts of the engine like the runs that TFL does in their tests, the computer is very close to calculated. On tanks where there are multiple stops/starts of the engine, it was off anywhere from 1-3 mph in every vehicles I have recorded. Generally, the more stops/starts of the engine the further off it was.
Also, the TFL loop does not use the mileage that each truck's computer says it has traveled. They use the actual distance of the trip, not the distance that the truck said it traveled. Not every vehicles speedo is 100% accurate and the standard for most manufacturers is a bell curve of about +/-3% the last I read. Tire wear and psi also effect the speedo which effects how many miles the vehicle's computer says it traveled which is what the ECM's mpg algorithm is based on.
