How accurate is the on board computer in figuring the average MPG , instantaneous MPG, and miles to empty? Thanks.

 

I hit 0 miles left till empty the other day and done about 1 mile more. I filled up and it only took 33 gallons so i guess i still had 3 gallons left on empty. Also from using the AVG mpg a lot latley it seems to be spot on. +/- 1-2%. Just today i done a 100mile trip on mountain roads and was very surprised to get 18.4 avg mpg. Best i have got so far.

 

My trucks says avg. MPG is 15.8, actual calc. = 14.65 MPG. This is a variance of 7.9%.
This is over the first 800 miles of driving.

 

She will lossen up a lot more after 2000-2500 miles. Im on nearly 5000 now and the mpg just keeps getting better and better. Would love to see what i could get out of her on a 0% grade for 100+ miles. Bet i could get 19mpg.

 

well i just got done with my road trip to DC i got 19 down and 18 back and that was hand math and the truck said 19.4 and 18.2 so its not to far off and i was dead on at 65 the hole way down but on the way back i hit traffic and sat for a little

 

Are you dividing your mileage by how many gallons it took to go 800 miles, or off of a single tank? I only have an 08, but I reset mine, and put 700 miles on it, keeping all of the gas receipts and did a total, and it was only "off" by .2 MPG, and it was actually better than what it was saying.

Those MPG guesstimates by the computer are a snapshot, and not an exact number. For instance, if you were getting 22mpg for 700 miles, and then sucking gas and getting 8mpg for 100 miles, it would probably tell you you are getting 14 or 15MPG in the end. I just reset mine now whenever I get a tank of gas, or ignore it.

 

That is about the same as my truck. Usually about 1 mpg difference between computer and actual MPG.

 

I keep track of each tank and also the running total. The last tank was the best, at 15.1 mpg.

 

I've had similar results. It seems to be fairly accurate. Mine has always been within + or - 1mpg of hand calculations, usually much closer.

 

i think the main key for the ampg to be right is that you need to reset it very time you fill up

and my truck just started pulling theis great number after 2000 miles on the clock