OK so I ran a full tank of gas through the truck, drove 515.7 miles burned 30.793 gallons. I filled up at the same exact pump. Calculated by hand, that is 16.75 MPG 70% City 30% HWY, 2 Launches, Some speeding, Some WOT runs from 40-70, fair amount of idling. Only problem is the Fuel computer in the vehicle said 17.6 Average MPG and 29.2 gallons used.

I do not like it when things are not accurate. Thoughts?

 

My computer is almost exactly 1mpg too low compared to hand calculation over the last two years, it'd be nice if it was right on but I can live with a consistent 1mpg difference.

 

On a trip to Florida. 2013 4x4 screw xlt with the 5.0 and 3.55 rear locker. About 99% highway. Cruise set at about 60 to 65

 

What do you guys figure the optimal rate of acceleration is? I mean….a jackrabbit start probably isn't super efficient but the really super slow acceleration probably isn't either. Do you want to hit the rpm with the highest torque or horsepower? Or…stay under 2K? I thought I read somewhere internal combustion engines are most efficient at WOT but that doesn't entirely make sense either. Any consensus?

 

You want to accelerate briskly to 40 mph not exceeding 2500-3000 rpm so you can get into 6th gear fast. Then finish accelerating slowly to your cruising speed.

 

Naturally aspirated engines are most efficient at full throttle, providing they didn't get carried away with the Power Enrichment. Brisk acceleration and predicting stops to maximize coasting will net your best mileage.

 

Mine consistently sits at an indicated 10.0-10.2mpg around town as it is in my sig. I don't have a heavy foot and it's a bit better than shown due to the bigger tires.

I'm glad I don't do much driving. At least I have a supermoto that does 40-45mpg city.

 

That's its impossible to get any more accurate than that with current technology and measuring methodology.

 

Well, the fuel Calculator in my Diamond is right on and works the same way, So that cant be tue.

 

Well, what I meant is for comparing mpgs. It might be accurate in calculating one persons mpgs over a specific period of time, but comparing that against a different time or person is pointless.

Type of fuel, wind resistance, weight (cargo), tire pressure, incline, speed, acceleration, etc. etc. etc. There are so many variables that comparing mpgs is pointless. I can have the same engine as you, take the same route to and from work as you, and drive the same way, and still not get the same mpgs. I can try to compare my mpgs last month to my mpgs this month, and that also is (less) pointless.

It makes for great conversation, but I wouldn't put that much weight on 1 mpg more or less.