AmericanRicer87

I have a 2000 Mustang GT 5sp. and i am getting 300 miles to a tank or so, its usually 23-24mpg about 200 of the miles are highway, i drive 75-80mph with a stock rear-end and it gets even better driving 80-90mph too. I would definately chang your plugs (make sure they are gapped right), change the air filter, change fuel filter, run injector cleaner for about 2-3 tanks of fuel and make sure the maff is working correctly. other than that idk.