Amazing response chaps, thought it was just mine, under 20mpg the tuning box looks to be doing a good job at increasing fuel by about 25% may consider one but its my weekender at moment {cant afford all week at moment lol}

Just got myself 1997 p38 auto diesel and checking mpg its doing about 18mpg not driving hard , is this the normal? i thought it may have achieved a bit more, wondering if a problem, new engine fitted with only done 64k

Cheers chaps

Just joined hello all