At the time of the boler trailer there was a growing popularity among average income small families to purchase compact 4 cyl. fuel efficient and less expensive automobiles. By 1973 a world-wide oil embargo causing fuel shortages, compounded by an economic recession, pushed consumers to consider changing over to sub-compact cars.
The boler came along at the perfect time by offering a lightweight affordable trailer that could be towed by any size automobile whether it was large or small.
The marketing of bolers to owners of small 4 cylinder cars was a running theme in most all of boler's marketing ads of the day including press articles (example: photo right from the Winnipeg Free Press Feb 12th, 1969)
Four and six cylinder 1970s compacts like the ones pictured below were well equipped to tow a boler trailer, most having a trailer towing capacity of 2,000 lbs and ranging in engine horse power from 50hp - 128hp. Cars like the Chevy Vega, Ford Pinto, VW Rabbit and Dasher, AMC Gremlin and Toyota Celica were specifically named in Boler advertisements of the day as cars that can tow a boler.
(Source for towing capacity: Popular Mechanics magazine Issue March 1974 article by Mort Schultz entitled 'Cars to take your rig in tow')
It was common place in the countrysides of Europe to see various makes and models of fibreglass trailers as heavy or heavier than the boler being towed with small 4 cylinder European autos such as Germany's VW Bug and the Czech Skoda.