How Fast Can A Lawnmower Go? You Will Be Surprised! [Video]How Fast Can A Lawnmower Go? You Will Be Surprised! [Video]I think the fastest I've ever gone on a riding lawnmower is 6 or 7 miles per hour (I'm a conservative driver) so I was blown away to find out how fast the world's fastest lawnmower can go:Leslie AnnLeslie Ann