This is an interesting thread. We can confirm David’s observation that 1.8 MPH is the most common low speed on
the gas-powered, self-propelled mowers we tested. Our speed range is also the
most efficient for our mowers’ motor and cutting performance. If you think that
your mower’s low speed is NOT 1.8 MPH, then there is a problem with your mower
and we’d like you to call us! As always, we appreciate the discussion and will
take the observations and suggestions to our product team.