Trip A over or under estimates MPG? - GreenHybrid

mwong99 · #1 (**permalink**) 03-14-2006, 10:15 AM

I was curious to see what others are getting on the 06 HCH MPG differences between manual calculation and Trip A indicator (assuming use of Trip A per tank). Below are stats from my last 5 fillups. BTW, I stop at 1 click when filling up.

OdoMiles TravelledGallonsMPG manualMPG Trip ADifference889456.309.55347.7744.7-3.071342452.509.73946.4652.45.941575232.604.76648.8051.42.602030455.209.69146.9754.37.332484453.8010.26844.2053.18.90

mwong99 · #2 (**permalink**) 03-14-2006, 10:19 AM

Looks like the stats spreadsheet did not paste properly. Here it is attached.

mexiken · #3 (**permalink**) 03-14-2006, 11:02 AM

You have to remember that filling up at gas stations is not 100% accurate. Even if you use the same pump at the same station, the varying pressure can cause it to give you a "click" at a different level of gasoline then the one before it, which will obviously skew your data. I would trust the computer more because there has to be a sensor there that is measuring fuel flow, and since it knows the miles traveled in its internal memory, obviously it can give you a MORE accurate readout of mpg. Hope this helps.

ElanC · #4 (**permalink**) 03-14-2006, 11:02 AM

Quote:

Originally Posted by mwong99

Looks like the stats spreadsheet did not paste properly. Here it is attached.

Those are large differences. One explanation could be that you have the 63 mile reset bug. So the Trip A mileage you see isn't really averaged over a full tank.

DTDRIVER · #5 (**permalink**) 03-15-2006, 06:42 AM

Last weekend I drove a low mileage HCHII on a 155 mile trip. I reset the trip meter and on arrival the mpg indicated 49.6 miles as I recall. About half of trip was under 70 and half above 70 mph. This is better than my 05 which has a lifetime average of 39.7 and current tank is around 41.2 mpg. I did not fill up the new one, so dont know what actual mileage was. My 05 varies +/- a couple of mpg doing it manually.

kenny · #6 (**permalink**) 03-15-2006, 06:48 AM

Quote:

Originally Posted by mexiken

You have to remember that filling up at gas stations is not 100% accurate. Even if you use the same pump at the same station, the varying pressure can cause it to give you a "click" at a different level of gasoline then the one before it, which will obviously skew your data. I would trust the computer more because there has to be a sensor there that is measuring fuel flow, and since it knows the miles traveled in its internal memory, obviously it can give you a MORE accurate readout of mpg. Hope this helps.

It is true that each single tank calculated at the pump will be off because you are computing using old miles and new gas.

But over time those pump variations will average out and I believe averaged pump calculations are more accurate than the number on the dash - even if you do not have the 63-mile bug.