The story of a bus that’s powered by poop…and which might be the fastest bus on the planet.

City buses have a long-standing image problem. There’s a widely held perception that they’re slow, pretty boring, and smell bad. The city bus program in Reading, a city in England, is trying to dispel those first two myths…while actually kind of embracing the third one.

Reading Buses is the local transit authority. It operates a lot of buses, but 34 of them are powered by cow manure. Okay, so the buses don’t really smell like cow poop, because of the highly scientific method by which the cow manure is converted to fuel. It’s called anaerobic digestion: in an oxygen-free environment, microorganisms break down the poop into biogas, which is then liquified and used as very efficient fuel. (And it’s a very renewable resource, which you know if you’ve ever been to a farm.)

One of those city buses is nicknamed The Bus Hound, named after the British Bloodhound, a supersonic racing car. The name is well earned, as The Bus Hound just set a land speed record for service buses, if not all buses, and certainly for buses powered by cow manure. It clocked speeds of 76.785 mph while doing laps around a track this May. That’s a record, although unofficially, because Guinness World Records says they can’t consider The Bus Hound’s speed unless it exceeds 150 mph, so as to make its claim undeniable.

Reading Buses don’t really care about an official record—the agency is just glad to raise awareness of biofuels. Another British bus is also raising awareness of biofuels, although a different kind. Bristol’s Bio-Bus helps people get to and from their destinations by running not on cow waste…but human waste.