Oh they certainly can... if powered for just what they need, and geared for transportation and mileage ALONE they can. But most, if not practically all, motorcycles were not built for mileage. If you look back into the past you will find some small Scooters and Micro Trucks getting 65 and 70 mph all the time. They weren't fast... or big... I have scooters that will give you 65 mph. And are fast... not big...

But then again... whats better for a situation? A scooter getting 65 MPH but only getting one person around? Or a Jetta getting 40 but getting five people around? Depends on how many people you want to get around. No one tool fixes all those problems. Next time Mr Motorcycle guy decides he needs to haul four or five people to work at one site he is going to miss that Mercedes. As it would have done it cheaper with one trip than four round trips with the bike. So it seems one can not always trade one thing for another and come out better. He needs both or more.

I think aerodynamics and gearing play a role, but still.... My Jetta certainly isn't a speed rocket, but neither is it slow like some scooter. 177 lb-ft of torque @ 1800 RPM feels pretty good.

why do motorcycles get such horrible mileage? 50-100 mpg isnt good at all if you ask me.

True... to some extent. We got scooters hitting 120 or better. Not fun but doing it. But most motorcycles were not built for gas mileage either. They just happen to do it. Its then what is the HP to Weight Ratio here. Your looking at bikes with 80 (or more) HP pushing 650 pounds getting 45. Thats probably better HP to Weight Ratio than the Jetta and yet still getting pretty good MPG's

In reality, motorcycles are not really economy vehicles (regardless of what we tell our wives). The get decent (but not great) mileage, only carry one or two people, and are only useful in nice weather. Also, many of them cost more than a four passenger economy car.

Craig, you've got an r80/ST the original dual-sport? Probly the best BMW worth owning since the R69S/2 was followed by crummy /5 "trash five" series notorious short wheelbase poor handling. And dont let anybody tell ye the BMW image is painful to endure.

Every MB diesel fan oughta git into motorcycling says me. Probly the best vehicle combo would be something like 240D + Hyabussa. Never in my life known motorcyclist who takes owning a car seriously.

(edit: the moto guzzi gets about 38mpg with d'elorto carbs. One lung thumpers the only bikes i known that git over 50mpg.

Believe or not, I think some Harleys came close to 50 mpg.

Actually the GS is the off-road version, and the ST (mine) is the street trim on the same frame. Mine is a red '83 (one of about 7000 made, about 1000 in the U.S.). I think they are cool little bikes, but a little too short for highway cruising. I originally bought it to ride to alaska, but I never made it; got married instead (long story, but I still have the bike and the tent). My benz indy keeps trying to buy it from me, I don't think so.

I believe the fuel injected ones can do that, they are geared pretty high compared to sport bikes.