FR Trip Computer Fuel Consumption Innaccuracy

Jimlad86

Active Member
Mar 30, 2010
233
1
Gloucestershire
Hello Everyone!

Long time browser and first time poster to these forums as i have just got myself an Ibiza FR! 2007 reg in black with 17k on the clock :)

I have just filled her up for the second time, and to test the accuracy of the trip computer i did a little calculation of my own. After filling up with 38.16 (8.39Gallons) gallons after 390 miles that works out as 46.5 MPG. Not to bad you might say.

My issue though is last time i filled up, i reset the trip computer longer 99 trip calculator thingy and that was showing 58.9MPG for the tank. Is it a known fact that these computers are totally inaccurate or am i missing something?

Thanks in advance for your comments folks!
 

Slippery_Stu

Active Member
May 23, 2008
72
0
I do regular calculations for every tank of fuel and find the the computer reading is 1-2 MPG consistently.

Below are the results from my last five tanks.....

Calc - 45.7 - 44.7 - 40.2 - 46.9 - 45.4
Comp - 46.1 - 46.4 - 41.7 - 47.6 - 47.6

Out of interest did you reset both MPG counters, i.e. switch between them using the button on the underside of the stalk and then reset - checking that both sets of readings get reset then try again.
 

Jimlad86

Active Member
Mar 30, 2010
233
1
Gloucestershire
I do regular calculations for every tank of fuel and find the the computer reading is 1-2 MPG consistently.

Below are the results from my last five tanks.....

Calc - 45.7 - 44.7 - 40.2 - 46.9 - 45.4
Comp - 46.1 - 46.4 - 41.7 - 47.6 - 47.6

Out of interest did you reset both MPG counters, i.e. switch between them using the button on the underside of the stalk and then reset - checking that both sets of readings get reset then try again.

I only reset the second one, the one that adds all your trips together up to a maximum of 99. Do you think that will have made a difference? Its strange how it is almost 15 mpg out!
 

Slippery_Stu

Active Member
May 23, 2008
72
0
I tend to reset both with each fill, then use one for current journey MPG and the other for the whole tank!

Really don't know why yours was so far out....
 

krussel

Active Member
Oct 31, 2008
1,713
2
Hertforshire
I ve found mine (fr tdi) is not too bad on a steady trip but for the short drives i do to work i find its reading up to10 mpg high.
A few weeks back when it freezing all week my trip said i'd ave 53mpg but when i worked it out at the pump it was more like 44 :cry:
 
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