With the 6" wide 15" wheels and the 195 width tyres the car is almost over tyred. There does not seem to be much point in fitting wider tyres unless the engine power has been significantly increased; something really only possible on a new GDI engined Plus 4 by changing the engine.
Putting 6.5" wheels would probably mean changing to 205 width tyres. The result would be heavier steering and more grip which would make the car handle differently.
There are a lot of Plus 4 cars which have actually been specified with narrower 5" wheels and taller tyres. The look is more classic, the steering lighter, and the car handles exceptionally well.
Perhaps it is better to try to drive a couple of cars fitted with different wheels and tyres before you decide.
I agree, Peter. There's a (literally as well as figuratively) heavy price to pay here. The best setup I believe is just enough tyre so the driver can provoke breakaway when they desire, whilst not breaking away when one doesn't. For lightness of handling and nimble steering, the narrower the better.
For track use of course it's a different matter, one is prepared to make all sorts of compromises for ultimate grip, you need it when you are cornering on the limit on every single bend.
But for road use, 99.99% of all driving is well within the dynamic limits of the car, and so tyres can be selected to give good handling characteristics. I have an engine more powerful than most Plus 4s at 165bhp, and I love having my 165 section tyres. The car doesn't let go unless I deliberately want it to when I'm in hooligan mode, and of course it looks much more the part in a vintage-styled roadster in my view.
