I have an ex U.S. 1969 TR6 (3.7 ratio diff), which I purchased with 195/65R15 tyres. Not a good match in my opinion; heavy steering, incorrect speedo and high RPM when cruising - even with overdrive.
I changed to Michelin XAS 180/80R15 in 2023 which completely transformed the car. With the XAS the car feels more agile. It is easier to drive with lighter steering. It goes dead straight when cruising. The speedo is correct, and the RPMs have gone significantly down. I'm very happy and will never go back to the wider, low profile.
