A question - GreenHybrid

case sensitive · #1 (**permalink**) 03-31-2004, 03:27 AM

When you guys list your mileage are you going by your display's or by the real method of fill up, and divide miles driven by number of gallons?

I don't have an MPG display (thanks VW), so all my numbers are done the conventional miles/gallons.

ericbecky · #2 (**permalink**) 03-31-2004, 04:25 AM

Good question.
My miles per tank is currently off of the display. Since I bought my car used and have misplaced some of my original receipts, so my lifetime is off the display as well.
I could change mine to hand calculations for tanks since January if that would conform to what everyone else is doing.
If I do a recalculation of lifetime mpg for myself, I will only be able to begin since January.

Hot_Georgia_2004 · #3 (**permalink**) 03-31-2004, 08:21 AM

Hi case sensitive:

My mileage listings are from the FCD on the car.
I don't manually calculate it every tankful but rather every 3.
So far it has been very accurate.

Since I only have about 5,500 miles on my car I've
only calculated it a couple of times.

Steve & family

ericbecky · #4 (**permalink**) 03-31-2004, 09:37 AM

I just double checked my calculated numbers against the FCD and there is a 2mpg difference between the FCD and the calculated.
FCD average mpg over the last 7 tanks (since 1/9/04 fill up) is 64.5. Calculated by hand I get 62.5mpg.

Rick Reece · #5 (**permalink**) 03-31-2004, 03:46 PM

Interesting my FCD tends to be much closer. I went by the FCD when I input my tanks but since I had 300 miles on the car when purchased at 38.4 mpg my overall average on the website is higher than my lmpg. Have fun, Rick

Jason · #6 (**permalink**) 03-31-2004, 05:05 PM

I don't bother checking my numbers manually against the screen. I figure that at most it's a mpg or so off. It isn't a huge deal.

xcel · #7 (**permalink**) 03-31-2004, 09:08 PM

Hi Case Sensitive:

___The spreadsheet containing my actual tanks and mileages show my lmpg at the last fill up = 79.58310773 mpg. That is 10,817.7 miles using 135.9296 gallons of fuel. My LMPG as shown on the Insight’s odometer display showed 79.6 mpg at that last fill up as well. My lmpg calculated here in the GreenHybrid lifetime mileage database is slightly above both of these at 80.3 mpg because the tank data form will not take the calculated mpg or the miles driven out to anything over 1 digit beyond the decimal point. Hopefully over another 10,000 miles, the discrepancy will average itself back closer to the actual as calculated or shown lmpg of my automobile …

___Good Luck

___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___Waynegerdes@earthlink.net

Jason · #8 (**permalink**) 04-01-2004, 12:19 PM

The database here will have an error of +- 0.1 mpg based on the data collected from your screen. There is little that can be done in this case. Sorry! For all practical purposes, though, they all say 80 mpg.

Rick Reece · #9 (**permalink**) 04-03-2004, 03:33 AM

Wayne,
Looks like your FCD is right on. Thats why I trust it more than the fuel guage on when to fill up. I can see as much as 3-4 mpg difference on manual vs computer determined mpg on a single tank (due to pump shutoff at a different spot) but on the lifetime they are nearly the same. Have fun, RIck

flare · #10 (**permalink**) 04-03-2004, 11:16 AM

I would trust the FCD more than manual calculations b/c when I fill up, the amount put it doesnt always equal the amount used up.