7.3 mpg trip on new 2013's history
#11
12-04-2013, 04:06 PM
Were I in your shoes, I would track and compare the miles divided by fuel versus the OBC for at least ten tanks of fuel to determine the standard error; two tanks and 22.5 gallons simply isn't a large enough sample size.
Edit:
I see that the tank size of your car is listed as 17.2 gallons; to minimize calculation error during your ten tank test, it would be best of you would drive the car all of the way to near empty before refilling.
Edit:
I see that the tank size of your car is listed as 17.2 gallons; to minimize calculation error during your ten tank test, it would be best of you would drive the car all of the way to near empty before refilling.
#12
12-04-2013, 05:09 PM
Right. Just make it 10 or 20 CONSECUTIVE fillups. That way each fillup might be more or less full, but will be corrected by the next fillup. Over a number of fillups, you get much less error if they are consecutive fillups.
However, if you keep clicking the nozzle to top off the tank, you introduce another error. When you do that, you risk the vapor-recovery system sucking liquid fuel back into the hose. You pay for that fuel, it registers on the pump, and you count it in YOUR calculation of MPG. But it doesn't get in your fuel tank so the onboard computer doesn't include it. This error can get larger if you fill more often from 1/2 or 3/4 tank.
Driving on different size tires will affect your MPG overall. But you base your calculation on the odometer reading, and so does the onboard computer. So it's still a valid comparison.
However, if you keep clicking the nozzle to top off the tank, you introduce another error. When you do that, you risk the vapor-recovery system sucking liquid fuel back into the hose. You pay for that fuel, it registers on the pump, and you count it in YOUR calculation of MPG. But it doesn't get in your fuel tank so the onboard computer doesn't include it. This error can get larger if you fill more often from 1/2 or 3/4 tank.
Driving on different size tires will affect your MPG overall. But you base your calculation on the odometer reading, and so does the onboard computer. So it's still a valid comparison.
#13
12-04-2013, 08:31 PM
Right. Just make it 10 or 20 CONSECUTIVE fillups. That way each fillup might be more or less full, but will be corrected by the next fillup. Over a number of fillups, you get much less error if they are consecutive fillups.
However, if you keep clicking the nozzle to top off the tank, you introduce another error. When you do that, you risk the vapor-recovery system sucking liquid fuel back into the hose. You pay for that fuel, it registers on the pump, and you count it in YOUR calculation of MPG. But it doesn't get in your fuel tank so the onboard computer doesn't include it. This error can get larger if you fill more often from 1/2 or 3/4 tank.
However, if you keep clicking the nozzle to top off the tank, you introduce another error. When you do that, you risk the vapor-recovery system sucking liquid fuel back into the hose. You pay for that fuel, it registers on the pump, and you count it in YOUR calculation of MPG. But it doesn't get in your fuel tank so the onboard computer doesn't include it. This error can get larger if you fill more often from 1/2 or 3/4 tank.
Thread
Thread Starter
Forum
Replies
Last Post
md7989
Off Topic
16
08-13-2011 06:40 AM