I went to the HD dealer yesterday and was checking out the new models and found that the new 500cc and 750cc bikes get really crappy mpg, at 41 mpg they are worse than almost every vehicle harley makes except for the 3 wheelers and 110cu dressers, all the other bikes get better or equal to the 500/750....I thought liquid cooled motors were suppose to be more efficient not less...I say buy a sportster, bigger motor and 7 to 9 mpg (depending on 883 or 1200) better mileage..plus they look better....

 

There are probably other criteria for buying a bike than just MPG. If MPG was most important then all of us would have Vespas and drive Priuses.

 

Crappy mpg means those Streets are tuned to run on the rich side of stoichiometric. Ideally air/fuel ratio should be 14.7 to 1.
This is needed to keep the cats hot and emissions clean.
Blame it all on the EPA.

 

That's true, but it does revive a question often asked and for which I've never heard a good answer: When a 2000(+)-lb car with a 2.0-ltr 4-cylinder engine can get over 40 MPG*, why does a 750-lb motorcycle 1.5-ltr 2-cylinder motorcycle also get only about 40 MPG?

(* such as the Maxda3 155-hp SKYACTIV-G 2.0L 4-cylinder engine, 29/41 mpg)

 

The Street 500/750 was designed for the international market and countries where gasoline is a hell of a lot more expensive than it is here in the US. Given the displacement and power advantage of a Sportster there really isn't enough of an initial price advantage to build a case for the 500/750 in America. But the 500 is the key. In certain countries the 500cc limit is the line anything over and the rider is hit with big tax penalties. That's why the 500 actually measures 499cc.

Even the V-Rod gets only 37mpg. Could turning a water pump really take that much off the mpg.

 

Cam size might have something to do with it. In order to get more power the new bikes might have higher lift, more duration. More power per CID from the liquid cooled bikes.


You do have to wonder about the fuel efficiency of all motorcycles though, not just Harleys. Seems to me that it could be better.

 

Most of the people that I know buy a bike based on looks/handling or both, mpg hardly ever enters their minds. As for the est. 41mpg, that's not that bad. A friend of mine once had a SE V-Rod and he only got in the 30's but his bike was built for performance not mileage. Who knows, maybe some will be able to get more or less than the 41, time will tell.

 

One reason is a car engine torque peaks at 2000 rpm and bike engines peak at double or triple the rpm of cage motors.

 

Fuel efficient cars are slippery at high speeds. Most bikes are not, contrary to popular belief.

Also, weight does not really play a factor when calculating highway fuel efficiency, since these figures are assuming travel on a flat roadway, where weight doesn't come into play...

 

The Street has a higher revving motor too. Much like the V-Rod the motor speed is like 1-2 thousand RPM faster for normal operating range. Vrod red lines at 9k RPM. Normal air cooled Vtwin is at 5500 RPM. I can't remember where the street red lines at.