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.
Best Long Haul Adventure Tourer: Where the Sommer is at home in the confines of city life and B-roads, the Track T-800CDI begs to be ridden far, wide and dirty. Looking like a Super Tenere’s sinister doppelganger, this Dutch diesel bike features long travel suspension, upright ergonomics, Brembo brakes and an engine stolen from a SmartCar. Hung from the WP trellis frame as it is, the modified 3-cylinder motor will launch the T-800 to 60 mph in under 4 seconds while delivering fuel economy numbers of up to 140 MPG. Driven by a CVT transmission, riding around takes a bit of getting used to — no blipping the throttle at red lights. Power delivery is said to be steady and linear, unlike the peaky turbo-diesel characteristics found in cars. This is the result of tuning and tampering to ensure a lifeline of up to 250,000 miles. If it all sounds too good to be true, it just might be: at last glance, Eva Products were selling only the blueprints to this oil-burning adventure tourer, with the hint of an all-electric version to follow shortly.
Neander Turbo Diesel
Best Diesel Power Cruiser: If bandanas and wallet chains are more your speed, the Neander Turbo Diesel just might lure you beyond the bar and shield for the next pony in your stable. From the quad-mount, twin-fork design to the enormous 260-width contact patch out back, the Neander has the custom cruiser look nailed — albeit a hefty-looking version. Power comes from a unique twin-crank, two-cylinder parallel set-up that was designed to offer optimal smoothness on the road and incredible grunt at the twist of a wrist: 112 horsepower and 144 lb-ft of torque make 60 appear in 4.5 seconds. A Garrett turbocharger whistles and pops as you shift through the 6-speed cassette-style transmission while final drive is delivered via a maintenance-free belt. At 650 pounds, the fact that the Neander will return 52 MPG, or about 10 better than Harley Davidson’s new CVO Breakout, is nothing short of incredible. The fact that you could buy four of those CVOs for one Neander — and still have change — is pretty incredible, too.
Star Twin Thunder Star 1200 TDI
The Diesel Crotch-Rocket: Star Twin’s Thunder Star 1200 TDI was rolling proof that tree-huggers may also wear knee-sliders. When their prototype was introduced in 2005, the Thunder Star was powered by a 3-cylinder, 1.2-liter turbo-diesel engine that first saw the light of day in the European-only Volkswagen Lupo. With some electronic re-mapping wizardry, Star Twin’s 450-pound (wet) super-sport could roast rubber, churning out 180 horsepower and 250 lb-ft of torque, or cruise around comfortably delivering 95 MPG. Outfitted as it was with top-performance brakes, suspension and carbon wheels, the Thunder Star clearly had apexes in mind with its design. The Thunder Star was also designed to ride in a comparable manner to the other lighter bikes of that era. Turning and braking would feel the same, but coming out of a curve, this diesel brute offered up the full monty of torque at about half of the rpm of its petrol-powered peers. If only they’d gone to market with it.
Hero MotoCorp RNT
The Likely Hero: While the other bikes on this list offer up serious goods — power, handling and classic aesthetics — the biggest hope for diesel-powered motorcycles probably lies with this little scooter. The Hero MotoCorp RNT is a two-wheel-drive, diesel/electric hybrid scooter currently under development for the Indian market. Powered primarily by its 150cc oil-burning mill, the RNT offers up 13.5 horsepower and an astonishing 26 lb-ft of torque — six less than Honda’s new CBR300R. The RNT also adds a 1.3 horsepower electric motor to the front wheel-hub to aid its go-anywhere, do-anything abilities, and a turbo for some extra kick. Luggage carriers abound, giving the RNT a refined-yet-rugged, Rukus-like appearance. Additionally, the RNT motor can be used as a generator when riders reach their destination. It may not be able to do the Texas Lean, but the RNT is the kind of evolutionary moto we’d love to see happen.