Right, my speedo is too far out as when I am at 40 mph on the speedo it reads 32 mph on them digital signs, at 60mph its like 53 mph or something. I am sure that the wheels are causing this as they are 185/55/14. What tyres will I need to get a similar rolling radius to the 13" with dounghuts that were most probably supplied with the car (I didn't take the original steelies when I bought the car).

I also have another speedo cluster I got from the scrappy that I can always try if the radius is not out.

Thanks in advance.