Sounds like you have the wider “Sport” wires fitted. Most Plus4s have the standard 6” wide wires with 195 tyres. There’s no reason why you shouldn’t fit that size tyre to your existing rims.
When I replaced my standard alloys with Minilites on my Roadster, I dropped a size to 195/65/15 and it certainly improved the feel of the car. Morgans really don’t suit wide tyres unless they are Aeros.
