Technically, both of these sizes are a fraction too wide for 4 1/2" wheels but the 185/65 should be fine, 185/70 (as 1800ES on 5 1/2" wheels) hard to find and very spendy, may feel a bit more squidgy. You may find a better solution with making some small adjustments to your front suspension settings, assuming that everything is currently tight and relatively unworn. A little bit of negative camber and careful setting of the toe-in could help keep you on the straight and narrow even with standard tyres. Tyre pressures can make a lot of difference too.
|