Lost the calculation
- but my 185/55/16 set up over reads by over 4% above 50mph
These wheels/tyres are slightly larger overall diameter than the stock 175/65/15 setup
yet still over reading!
So I am comfortable with using a slightly fatter tyre - the online calculator tells me I will have a 1.8% increase over the 185/55/16 - so I make it that I will still be slightly over reading and therefor at speedo 70mph I will still be under 70mph actual. (but more close to accurate)
My insurance company posativly endorsed the idea - they seemed to think that a fatter tyre is always a better tyre!!!
While I will benefit from paying less for a given tyre (about 5%) and also have much more choice available - that is really NOT my reason for considering a fatter tyre. Ultimately there has to be a little more rolling and wind resistance, and on very wet roads there is a slight increase in the possibility of aquaplaning - so I will try to choose carefully balancing the advantage of cheaper options against wet (primarily) perfomance.
It will make the ride very slightly more comfortable and at the end of the day the increase is very small
so it shouldn't make cornering spongy for that small a difference.
Next month I will be buying - so I will report back posative or negative results and observations.