On Alfa number 15
AO Platinum Member
Join Date: Dec 2005
Location: United Kingdom
Exactly, the sidewall height is pretty much the same on a 205/50 R16 as it is on a 225/45 R16.
Another factor is that you have just swapped an old set of tyres that have degraded gradually for a new set.
Contact patch is the same size, as the contact patch depends on the tyre pressure and the vehicle weight rather than the tyre width.
The only difference will be that a wider tyre the patch is wider, but shorter in length.
It is down to the equation Force = Pressure x Area or Area = Force/Pressure
To get a bigger contact patch (Area) you would either need to increase the weight of the car (Force) or decrease the tyre pressure.
Ian, did you use the same brand and type of tyre? Some tyres have more grip and stiffer sidewalls than others which will affect the turn in and the levels of grip when pulling away.
You will never be cool driving a Vauxhall.