Hi, can you tell me what figures you are getting from your Procee'd 2.0 crdi Sports please, I am only getting 40.5 on the combined cycle that is 50/50 urban and motorway, and for most of the time i have not got a lead right foot!
Not bad. I've a 61plate 1.6 128bhp and am averaging 30.7mpg at the min or so the trip computer says.
In all seriousness though its hard to say why the MPG is so low on random kia cars. Some arn't to bad. Injector cleaning adatives sometime help, and make the engine run a little better.
As for rattles and knocks it might be worth having it looked at for worn bushes or bearing's. They could also be a reason for poor MPG. Check your tire pressures and the tread for an equal wear pattern