I could understand the logic behind the theory... wider wheels would require more tourque from the engine to get them moving, the power steering would have to work harder to turn the wheels but as for the suspension part I'm lost.
There will be a lack of pulling power with wider wheels as they grip better and the lack of tourque means you do loose a few points of a second in acceleration. But I use 205/50/R15 wheels on the motorway and prefer the comfortable amount of grip they give.
