Can anyone help please? I have just had two new Toyo Proxes Comfort tyres (205/55/R16 91V) fitted to the front of my Astra H Design estate 1.6-litre and it's now like driving through treacle with how sluggish the car has become. Does anyone use this brand/size of tyre on their Astra and have had any issues or change in the mpg-rate as my economy is down about 5 mpg? Any opinions, thoughts, etc would be appreciated. Cheers.