Petrol-powered motorcycle engines rival those of a modern supercar for their stratospheric redlines and lopsided power-to-displacement ratios. Even those with more grumble and less braaap are motivated by punchy, lightweight, incredibly balanced fuel-fed motors with fuel economy figures most Prius owners can only lie about. Diesel engines, on the other hand, are limp, low revving and lethargic — or at least they used to be. If two-wheeled hypermiling is your game, you may want to consider turning to the dark side. Diesel mills offer bullet-proof reliability, stump-pulling torque and the kind of range even Ted Simon can only dream of. And refueling doesn’t involve extended time out of the saddle. It’s enough to make one wonder why there aren’t more on the market. We found five examples that would look great in the garage and on the road: these are the best diesel motorcycles, past, present and future. Let’s hope that if they build them, more will come.
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Sommer Diesel 462

Best Old School Oil Burner: Originally built using donor bikes from Royal Enfield, the Sommer Diesel 462 is a bit of a rolling relic that makes an excellent scooter alternative. Devised for the European market and hand-built in Germany, the Sommer places reliability and economy well above speed. Its 462cc, single-cylinder, 4-stroke motor churns out less horsepower than most American lawn mowers (11 horsepower). But with 20 lb-ft of torque on tap and a four-speed gearbox, Interstate travel isn’t exactly out of the realm of possibilities as this retro thumper tops out just shy of 60 mph. Considering it would cost about $120 in fuel to cruise from New York to L.A., riders may just be inclined to give it a shot. The Sommer delivers an astounding 117 MPG and goes at least 300 miles between top-ups. Just be careful with that kick-start when you’re ready to roll again; compression runs around 20:1.