Fuel Issue... Maybe?

[sn95jones]

So.... I picked up my 04 GT last night from the dealership, had a full tank or atleast appeared that way. Drove 50mi home, gauge barely moved which was the same way with my 98 GT. Drove the car about 100mi since the dealership and notice my gauge gauge was down to half a tank. Car is stock with the exception of exhaust but I don't remember my 98 GT going through half a tank in 100mi, maybe I been out of the SN95 game for too long and just forgot but 100mi on half a tank just seems off. I put $10 in the tank @ $2.05 a gallon, brought it back up to just under full tank.

Something seem off or am I just being crazy?

 

[sn95jones]

Maybe it's not off....

04 GT has a 15 gallon tank
Half a tank is roughly 7.5 gallons
@ $2.05 on $10 thats, 4.8 gallons
Divide 100 miles by 4.8 gallons thats roughly 20mpg.
Factor in that the additional 2.7 gallons that it would take to fill it up which would lower the mpg down to maybe 17mpg?

So maybe it's not off?

 

[CC'S95GT]

AS long as it's accurate at E does it really matter what the rest of ther gauge says?
The only to accurately calculate your MPG's is to start with a FULL tank then set your trip odometer to zero. Drive 150 -200 miles then FILL the tank again. Divide gallons into the miles travelled.