John, that is the rule of thumb when driving a Model T. If you think driving hills or mountains is tough in a Model A, try it in a T. I drive my A in the mountains because that is where I live. I drive mine just like a modern car but, make sure the brakes work as they were designed to.I think once upon a time there was a rule in Sweden that one should go down a hill in the same gear you went up it ; rather a good maxim. Having said that I have now come round to believing that gears were designed to propel you forwards and that brakes were made for slowing you down. I certainly no longer change down to drop the speed, but brake to a suitable speed and then change down.