rev counter

Not about the A2, in fact glad ours don't fall into this category.
There's a saying that the only dim questions are the ones you don't ask, but all the same this may be a dim question. Most cars since rev counters became standard fitting, since the 50s or 60s, show the rev counter marked in hundreds, ie 10,20,30 etc, and not in thousands, ie 1,2,3 etc. Given that we would always say two thousand revs and not twenty hundred revs, how did this come about ?


A2OC Donor
Blame James Watt and fellow engineers for that, some early engine rpm was only up to 1000rpm and they used the smaller scales. As engines revved higher the scale was reduced. There was also no longer a need to accurately read e.g. 812 rpm. Some gauges have graduations every 100 rpm, some every 200 rpm and others just the thousands with perhaps additional marks near the yellow or red line rpms.