hi folks.. I have a e class 220 cdi which is only doing 23 mpg around town..it has had a full service, thermostat replaced, gearbox oil change and injectors test.. 1 injector is reading a wee bit more than the rest. the gear change when accelerated hard is very sloppy with a sudden judder when changing 3 rd to 4th but not all the time.. I cleaned the auxiliary battery terminals and it did seem to go better but then it went back to normal..please help as I love the car but about afford to run it..I'm getting 120 miles for £40 at 1.43 per litre..thanks