Just fitted a 52mm throttle body and I can't believe the difference. I have been having a few problems towing a 1300kg caravan, nothing too drastic just heavy fuel consumption and shifting up and down the gearbox. I had looked at a remap but didn't consider this to be cost effective, so having had a MGF until last year I remembered some comments re the 52mm throttle body giving better response and being a little more tractable. Pulls a higher gear than it used to do, responds to the pedal much better, just hope the fuel consumption improves. The fuel consumption was OK solo at 25mpg but going from Sheffield to Whitby only 17mpg which made the wallet sweat a bit, and 20mpg on the return trip, with my old van 1100kg I got 25mpg without trying, 8mpg difference fo 200kg just seemed excessive.