Add this code to your sig.
But replace ALL the curly brackets with square ones, and change both instances of
NUMBER with the vehicleid number you see in the URL when you call up your fuel log (e.g. mine would be
sig11a.png).
Code:
{URL="http://ecomodder.com/forum/em-fuel-log.php?vehicleid=NUMBER"}{IMG}http://ecomodder.com/forum/fe-graphs/sigNUMBERa.png{/IMG}{/URL}