Welcome to Iboats,
Who told you that lie ? Tohatsu impellers will outlast and other brand impellers on the market, due to being made with elastomers not plain rubber as found in all other brands. At a unavailable stock, you can flip them if in need.
Happy Boating
The average impeller will last over 500 hours of normal operation or 5 years. Whichever comes first. However, environmental conditions can shorten that. IE Running an engine in sand or running the engine dry will shorten the service life quite a bit. I don't see any difference in how long the impellers will last in different Japanese engines, but, historically US outboard impellers don't last as long...Except the US engines that are actually made in Japan![]()