mpg reading problems

[Spudgun]

hi guys

i have noticed of late that my mpg on the trip computer has fell through the floor last night i could only manage 35 mpg this was a mix of driving

it all started after putting my amp power cable in and i am worried that i could have broken something is this behaviour normal

i also have only done 150 miles to half a tank

the car is an 06 plate with 5300 miles on the clock

cheers guys

[ric04vrs]

cold weather knocks the mpg down , see the other thread about this , also the newer EURO4 cars seem to have worse fuel consumption than the older EURO3 cars

[Spudgun]

but even when the weather is mild it is rare it will reach 40 mpg before i hooked up the amp power cable i was getting 45 mpg +

[ChrisRs]

Unplug it and see if it improves

[Spudgun]

thinking about it i attatched the cable between the battery terminal and the engine power cable well thats what i think it is it attaches to the left hand side of the positive terminal if i move the cable and stick it elsewhere would this possibly cure the problem