Why Do Motorcycles Get Such Horrible Gas Mileage?

 My truck weighs about 3000 lbs. and gets about 20 MPG.

My motorcycle, which weighs about 500 lbs. should then get about 3000/500 *
20 = 120 MPG.  It doesn't.

What is the flaw in my reasoning?  Why isn't motorcycle gas mileage better?

Two possibilities that come to mind immediately are:

a)Car engines have historically been under more pressure to get more MPG, so
there is more engineering maturity there.

b)MPG is related to difficulty in pushing the object through the air, not
necessarily to weight.  Motorcycles may not be especially aerodynamic
compared to cars, so they may take comparatively a large amount of power to
move through the air.

???

Datesfat.

 

Look at a big diesel over-the-road rig... it
gets about 6mpg, pulling  80,000lbs.

Several things going on, including the
economy of scale.  Diesel is also more
energetic than gas.  Your motorcycle has
a lot of extra acceleration... much more
than your truck.  If you bought a Spree,
you'd be getting much closer to the economy
you're looking for... this is my recommendation.
__
Steve
.

 
I don't see a Spree in my future.  But thanks for the thought.

Seriously, the White House is working with the auto makers to mandate 42 MPG
average for cars in the near future (which implies that some will do better
than 42 MPG).  When I looked at Suzuki's website, I noticed that a lot of
the bikes that perform well have economy in the 40 MPG range.  The Bandit
1250S (which I have reason to believe will go at least 55 MPH) says 39 MPG
city.  The Hayabusa and B-King don't list mileage at all, which suggests it
might not be great.

I was just musing about why this is possible, considering that a car is
bigger.

Looked at the Wee-Strom at the dealer today and discussed trade-in value of
my bike.  Apparently 16,000 miles (what I have on my bike now) is considered
a lot for a 2006.  Salesperson didn't discount the trade-in value much, but
it was an observation.  I won't make a decision until I've seen the Wee in
orange.  The Wee is the best compromise I could find between performance and
mileage.

Then there is the standard negotiation with the dealers, which would drag on
into the Winter.  If the list on the bike is $7,500, I won't touch it for
more than $6,500.  Allowing $2,500 for my current bike, that leaves me with
a balance of $4,000.  It would in practice take about a month of casual
discussions until the dealer figures out that when I say $6,500 is my
decision point, that is exactly what I mean.  I suppose I could cut some
time off by offering $5,500 initially and claiming I won't go higher.  That
might bring it down from four weeks to three weeks.

With any luck, and weather permitting, I'll have a new ride out to Bridge
Day.

http://www.876ft.com/

http://www.wvbridgeday.com/index.php



Datesfat

 Datesfat Chicks wrote:


*Mandating* a 42 mpg average for cars does NOT[1] mean some will get
more than 42 mpg. I could mandate that everyone will have a genius IQ,
or even mandate that everyone in government will magically develop an
IQ over 100, but making a law saying so isn't going to make it happen.
Actually I would love to see a law mandating a minimum number of sunny
days per month where I live.

[1] Yes, I understand the meaning of average, I also understand the
mean value theorem and how to integrate the volume of an ice- cream
cone. It may be possible to make the auto fleet average mileage hit 42.
I guarantee the general public is not going to like their choices when
they discover what that means in terms of cost, how powerful their cars
engines are, and how small the new cars are.  I drove a little Ford
wagon in Europe that had a 1.4 liter TDCI engine that got over 50 mpg
and was a very nice car that would sell very well in the US.  But it
was quite small and wouldn't do much good pulling even a small tent
trailer.

 

There is also the Smart car. The older one got some 70mpg (imperial) with
a diesel engine. It wasn't clean enough so it's been scrapped.
Great little city car for two with no luggage.
Top speed is only about 60-70mph and city mileage is about the same as
highway or a bit better.
Fine for Europe. Not so good over here.

Also fine because people in Europe understand that the slower cars stay
in the slow lane and all major highways are at least three lanes while
most minor ones are two lanes each way.

For some reason the middle lane almst always seems to be the slowest
where there are 3 lanes to choose from over here.

Average is such a misleading word. Unfortunately it is the catch-all that
most people seem to comprehend.
Do they mean Median? Mean? Weighted? Everything within one standard
deviation?
Too many ways to define "average".

--
Bob Mann

Cap'n, ah need moor pow'r.