255/40 R19??

Hi all,
I have a 1.5 sport and will need tires soon. Has anyone went from 235s to 255s? I had a tire salesman tell me they would probably rub and of coarse make my speedo read 5 mph off. I did the online tire comparison calculator and the speedo difference is 2 mph at 95 mph and less than a 2 mph difference below 95 mph. I personally don't think they will rub. I have not nor plan on lowering the car. I mainly would like a wider tire for performance and to better protect the rims.

Also what's the best tire for performance and tread mileage?? I have the factory goodyear eagle touring now and was not happy with them at all.

Thanks!