question: Why are small motorcycles so loud when much larger cars are so quiet?
comment: Most of the noise an engine makes can be mitigated by the exhaust system, the shorter the exhaust the louder it is. On a motorcycle there is only so much space but in a large car there is enough room to dampen the sound with a large exhaust system. Additionally, the engine sits in an enclosed space further reducing noise.
passages: Outside the United States, engine capacities typically ranged from about 50 cc to 650 cc; but in Europe since 1968 motorcycles with larger capacities have become common, ranging as high as the Triumph Rocket 3's engine. In the United States, V-twin engined-motorcycles with capacities of 850 cc or more have been the norm since the 1920s.
  
  Section::::History.
   The overwhelming majority of the motorcycles produced and used in the world today have small displacement air-cooled single-cylinder engines, both two- and four-strokes. In the wealthier parts of the world, Europe and Japan, larger displacements and multiple cylinders are common alongside small-displacement bikes required by various licensing and rider experience requirements, and so a very diverse range of sizes, cylinder numbers, configurations, and cooling systems are seen on the road. Many developed countries have graduated licensing, where a rider is licensed for a period of time to ride only smaller-displacement motorcycles before being allowed to ride larger ones. In the United States, there are no such mandates, and so the mix is skewed even further to the largest displacements, consumer demand drives manufacturers to offer their largest motorcycles to that country, and to export far fewer sub- models to the American market.
   BULLET::::- Motorcycle Light : Engine size is between 125–250 cc, identified by green text and white small license plate.
  
  BULLET::::- Motorcycle Medium : Engine size is between 250–400 cc, identified by green outline and green text with white small license plate.
  
  BULLET::::- Motorcycle Large : Engine size is over 400 cc, identified by green outline and green text with white small license plate.
   In the less developed world, smaller engine sizes are the norm, and relative terms like small, mid-sized and large displacement can have different meanings. For example, in India in 2002 there were about 37 million two-wheelers, but as of 2008, there were only about 3,000 motorcycles, or fewer than one in 12,000, of displacement or more. Similarly, the perception of relative sizes has shifted over time in developed countries, from smaller to larger displacements. When the original superbike, the Honda CB750, appeared in 1969, it was called a "big four," while today an inline four of would be classed in the middle range.
   BULLET::::- Rally raid, or "rallies" — A special type of enduro bike with a significantly larger fuel tank for very long distance racing, typically through deserts (e.g. Paris-Dakar rally). Engine capacities tend to be larger, usually between 450 cc and 750 cc.
   BULLET::::- "Invisible" EP
   Other types of small motorcycles include the monkey bike, Welbike, and minibike.
  
  Section::::Off-road.
   Until the mid-1960s, road-racing machines, like the UK's Matchless, AJS and Norton, tended to be large singles, but since then multicylinder racers have become the norm. Off-road and smaller dual-sport bikes tend to use single-cylinder engines. The simplicity of these engines, often relying on a single carburetor, make them relatively easy to maintain and repair in remote locations with few tools.
  
  Compared to lightweight off-road singles, the modern category of heavier off-road adventure bikes tend to forgo such simplicity, and instead have larger and more powerful parallel-twin, flat-twin, or V-twin engines.
  
  Section::::Cylinders and configuration.:Twin.
  
  BULLET::::- Straight-twin
   Section::::Technical aspects.:Fuel economy.
  
  Motorcycle fuel economy varies greatly with engine displacement and riding style. A streamlined, fully faired Matzu Matsuzawa Honda XL125 achieved in the Craig Vetter Fuel Economy Challenge "on real highways in real conditions."
  
  Due to low engine displacements (), and high power-to-mass ratios, motorcycles offer good fuel economy. Under conditions of fuel scarcity like 1950s Britain and modern developing nations, motorcycles claim large shares of the vehicle market.
  
  Section::::Technical aspects.:Fuel economy.:Electric motorcycles.
   Motorcycles also have classification definitions based on engine size:
  
  BULLET::::- Class I Moped : Engine size must be at or less than 50 cc, identified by blue text and white extra small license plate.
  
  BULLET::::- Class II Moped (B) : Engine size is between 50–90 cc, identified by blue text and yellow extra small license plate.
  
  BULLET::::- Class II Moped (MIG) : Engine size is between 90–125 cc, identified by blue text and pink extra small license plate (color of plate can vary according to regional requirements)
   BULLET::::- Category LA: two-wheeled mopeds (generally, volume of cylinder not exceeding 50 ccm, design speed not exceeding 45 km/h)
  
  BULLET::::- Category LB: three-wheeled mopeds and light four-wheelers (generally, volume of cylinder not exceeding 50 ccm or motor power not exceeding 4 kW, design speed not exceeding 45 km/h, mass of empty vehicle not exceeding 350 kg)
  
  BULLET::::- Category LC: motorcycles (two-wheeled, with one or more parameters exceeding the LA category)
  
  BULLET::::- Category LD: motorcycles with sidecars (with one or more parameters exceeding the LB category)
   BULLET::::- Dude atv specifications
  
  BULLET::::- "There was an attached statement that range would vary depending on hill grade, speed, and rider weight."
  
  Section::::Fleets.:ZAP Truck XL.
   In the UK, due to the cost and lack of availability of the v-twin engine, many chose to use British engines from bikes such as Triumph or BSA; following an increase in imports, Japanese engines have seen more use.
  
  Section::::Choppers in Australia.
   Section::::Singles.
   Section::::Electric vs. gasoline machines.:Noise.
  
  Electric vehicles are far quieter than gas powered ones, so silent they may sneak up on unwary pedestrians. Some are equipped to emit artificial noise. Popular Mechanics called the comparative quiet of electric motorcycles the greatest difference between them and their gas counterparts, and a safety bonus because the rider can hear danger approaching. Whether a loud motorcycle is more noticeable and thus more safe than a quiet one is contested. At high speed the whine of an electric motorcycle is said to sound "like a spaceship."
  
  Section::::Sales and adoption.
   Motorcycles may only be driven on a motorcycle (class 6) licence; a moped can be driven on a car (class 1) licence. Riders on their learners or restricted motorcycle licence can only ride approved motorcycles on the Learner Approved Motorcycle Scheme list. These motorcycles must have an engine capacity of 660 cc or less and a power-to-weight ratio of 150 kW/tonne or less (when including a 90 kg rider). Motorcycles with an engine capacity of 250 cc or less are automatically approves, except for a small number of high-performance machines. Pre-1960 motorcycles are exempt from the power-to-weight ratio restriction.
   In the 21st century, the motorcycle industry is mainly dominated by the Indian motorcycle industry and by Japanese motorcycle companies. In addition to the large capacity motorcycles, there is a large market in smaller capacity (less than 300 cc) motorcycles, mostly concentrated in Asian and African countries and produced in China and India. A Japanese example is the 1958 Honda Super Cub, which went on to become the biggest selling vehicle of all time, with its 60 millionth unit produced in April 2008.
   This is because many motorcycles lack a catalytic converter, and the emission standard is much more permissive for motorcycles than for other vehicles. While catalytic converters have been installed in most gasoline-powered cars and trucks since 1975 in the United States, they can present fitment and heat difficulties in motorcycle applications. 
   Because the fairing is attached to the vehicle via the front axle, it is prone to clunky vibrations at low speeds and on turbulent surfaces. The nature and position of the motor produce a constant, loud mechanical sound much like a motorcycle. The weight limit for the vehicle, including the driver and all carried cargo, is 200 pounds.
  
  Section::::Design.:Kits.
   The addition of a power limit was a response to the ever-increasing power outputs available with turbocharging and multi-valve technologies popularized in the late eighties. Engine technology was also shared with sport bikes, which are designed for rider enjoyment, and less so for fuel economy - going against the idea of small, people's cars.
   The displacement is defined as the total volume of air/fuel mixture an engine can draw in during one complete engine cycle. In a piston engine, this is the volume that is swept as the pistons are moved from top dead centre to bottom dead centre. To the layperson this is the "size" of the engine. Motorcycle engines range from less than 50 cc (cubic centimetres), commonly found in many small scooters, to 5735 cc, a Chevrolet V8 engine, currently used by Boss Hoss in its cruiser style motorcycle.
   BULLET::::- Less noise while traveling, because the groans squeaks and rattles normally associated with bodywork movement due to stresses and strains are not heard so much, and road noise from tires is more "distant," all due to the bodywork being isolated from the chassis by rubber pads around the attachment bolts, or by suspending the body on the chassis.
   Paramotor noise relative to an observer depends on distance, loudness, frequency and timbre of the power unit. Most noise comes from the propeller and slow rpm is perceived as the quietest. Pilots mitigate their sound impact by leaving a noise-sensitive area at low power, keeping the farthest practical distance away, and reducing time spent near the area.
  
  Section::::Safety and regulations.:License and training.
   Even without regulation, there are strong individual economic pressures for quieter vehicles, because owners and employers see quieter vehicles as more luxurious and less stressful. The tighter regulatory requirements of the EU and Japan encourage quieter design even in unregulated countries, because most car manufacturers aspire to international sales. On the other hand, individual owners of motorbikes, 'boom-box' cars (with very loud music systems), and 'muscle-cars' may prefer their vehicle to be louder (at least at idling or low speeds), and such noise (often from modified exhaust systems) can only be controlled by on-going inspection and sanctions.
   BULLET::::- Automotive Brake & Exhaust, Sioux Falls - 'Mr. Bendo', arm upraised if holding an exhaust pipe in one hand
  
  BULLET::::- Full Throttle Saloon (new location), 'Windover Willie' originally from Winnemucca, NV. Located at 19942 Hwy 79, Vale, SD - Cowboy holding a cigar in his left hand and a mug of beer in his right.
  
  Section::::Texas.
  
  BULLET::::- Red McCombs Big Chief in downtown San Antonio, Texas
  
  BULLET::::- Mr. Bendo, Paul Bunyan, at San Angelo, Texas
  
  BULLET::::- Glenn Goode and Mary Jean Goode's "Big People!": Cowboy, 2 Big Johns, and a Uniroyal Gal in Gainesville, Texas
  
raw_presuppositions: Because motorcycles are so small, they should make less noise than cars which are much larger.  Small motorcycles and larger cars should make the same amount of noise.
raw_corrections: Motorcycles have shorter exhaust pipes than cars, which enables them to be much louder.  Since the shorter the exhaust pipe the louder the noise, motorcycles make more noise than cars.