motorcycle engines?

Question

if harley davidson can make an engine that can go about 80mph/gal on a bike, why cant they build carsto do the same?

POSITIVE replies only thanks

well 80 miles may sound a bit off but the bus driver who takes me to school was wondering and i said sounds like a job for... yahoo! answers!

please keep answering and editing all reponses.

grizz, he was speaking hypothetically. with gas at an all-time high, he was asking for an opinion on how my question could be done.

Answer 1

WEIGHT. Not wait. If a car could weigh 500 to 800 lbs like most street motorcycles then they too could achieve huge mileage figures. Frontal area. A motorcycle pushes much less air than a car. Air drag caused by frontal mass is the same as adding many many pounds of product. Emission controls. Cars must have them. Motorcycles are exempt, (except in Californa). Emissions controls decrease gas mileage. Engine size. Although some motorcycles' engines are approaching sizes found in cars they are typically much smaller. Less fuel hungry.

Answer 2

They can absolutely make a car that gets that kind of mileage...we put men on the moon, build aircraft that can go over 3000 MPH, build lasers, computers, satelites and genetically alter animals....theres only one reason someone hasnt come up with a car capable of getting that kind of mileage....BECAUSE THEY DONT WANT TO........for over 15 years the auto industry has lobbied congress NOT to raise minimum mileage standards....the Oil lobby has done the same thing....why?...because if we get 70 or 80 MPG we might only need 6 gallons a week and the oil industry will lose money.....

Answer 3

probably the new HD 883 can get about 57 MPG not 80
there are two physics problems here.
First is power. You need enough power to operate at highway speeds for reasonably long stretchs, Also you need enough power to pull into traffic that may be moving at highway speeds
Problem 2 is weight. The more weight, the worse the mPG
HD 883 with about 50 HP andd 500 pounds gets 57 MPG
If you want t a car to get that MPG it needs to be very verylight

Answer 4

The problem starts with our government. They don't really give a rats a-- about fuel economy. I just purchased a 2006 ford cargo van for my small business. I get 10 to 12 mph. I nearly died when I filled the tank and the bill was over $100.00. Our government leaders do nothing to push the auto industry to get better fuel economy. I believe they can get better mph on auto's but I also believe they are in cahoots with the fuel industry. Also, With all the taxes on fuel, the more we use, the more $ they bleed from us. Really sickens me.

Answer 5

If your bus driver told you that an H-D, or any motorcycle, can give you 80 mpg at 80 mph he is lying. As many have said before, it is a power to weight thing. Those kind of numbers are not possible with our current technology.

Answer 6

the only way a harley can do 80 mph and return 80 mpg is something like down everest, or maybe the grand canyon. its just not possible., and if it was the olil companies would buy the patent to stop anybody making the motor.

Answer 7

It's all a matter of mass. Motorcycles are light, cars are heavy. According to the laws of physics, that means it requires a lot more energy to move cars around than motorcycles. That's also why the new smart car, not a whole lot bigger than a motorcycle, gets 60 mpg on the highway.

Answer 8

It sounds like you're thinking of a microcar, a tiny four wheeled street vehicle with a motorcycle sized engine. Steve Urkle's BMW Isetta or Cousin It's Kabinnenroller from the Aadams Family are two examples from TV and movies. There's a museum full of them not far from my house; you may wish to check out their pictures online:

http://www.microcarmuseum.com/

Answer 9

Displacement to weight ratio.

As technology advances; the implementation of using ultra light and ultra strong composite materials will become increasingly more prevalent.

To obtain that type of fuel economy in my 3/4 ton diesel pick-up; I would have to have an engine that is approximately 800 liters. Whoa!

Answer 10

it's a power to weight ratio problem. the more something weighs the more power it will take to propel it. in drag race cars the general rule is that for every 100 pounds of weight you reduce from the vehicle you will gain 1/10th second from your 1/4 mile time. there are alternative fuels that could produce more power from the same volume of fuel but they cost more.