This brochure from Husqvarna was in the mailbox today. Nothing unusual, you say?
Check this out:
engine displacements: cubic centimeters, in metric
power: horsepower, an English measure
weight: pounds, an English measure
In lawn mowers (not shown here), radius of the cut was shown in inches, engine displacement was in cubic centimeters, and power output in horsepower.
It was the same mish-mash all the way through. Forty years after official metrication, no one uses metric for certain essential measures. Metrication happened one or two generations ago. It is not as if people had not gone to school in metric. Speculation is welcomed.