Scooters, Underbones and Mopeds

Scooter engine sizes range smaller than motorcycles, 50–850 cc (3.1–51.9 cu in), and have all-enclosing bodywork that makes them cleaner and quieter than motorcycles, as well as having more built-in storage space. Automatic clutches and continuously variable transmissions (CVT) make them easier to learn on and to ride.  Scooters usually have smaller wheels than motorcycles. Scooters usually have the engine as part of the swingarm, so that their engines travel up and down with the suspension.

Underbones are small-displacement motorcycle with a step-through frame, descendants of the original Honda Super Cub. They are differentiated from scooters by their larger wheels and their use of footpegs instead of a floorboard. They often have a gear shifter with an automatic clutch.
The moped used to be a hybrid of the bicycle and the motorcycle, equipped with a small engine (usually a small two-stroke engine up to 50 cc, but occasionally an electric motor) and a bicycle drivetrain, and motive power can be supplied by the engine, the rider, or both. There is also Sport mopeds – a type of moped that resembles a sport bike.
In many places, mopeds are subject to less stringent licensing than bikes with larger engines and are popular as very cheap motorbikes, with the pedals seeing next to no use. Mopeds were very popular in the United States during the fuel-crisis of the late 1970s and early 1980s, but their popularity has fallen off sharply since the mid-1980s. In response to rising fuel prices in the first decade of the 2000s, U.S. scooter and moped ridership saw a resurgence. Sales of motorcycles and scooters declined 43.2% in 2009, and continued to decrease in the first quarter of 2010, with scooter sales doing worst, down 13.3% compared to a 4.6% drop for all two-wheelers.
Other types of small motorcycles include the monkey bike, Welbike, and minibike.

Off-Road Motorcycles

There are various types of off-road motorcycles, also known as dirt bikes, specially designed for off-road events. The term off-road refers to driving surfaces that are not conventionally paved. These are rough surfaces, often created naturally, such as sand, gravel, a river, mud or snow. These types of terrain can sometimes only be travelled on with vehicles designed for off-road driving (such as SUVs, ATVs, snowmobiles and mountain bikes) or vehicles that have off-road equipment. Compared to road-going motorcycles, off-road machines are simpler and lighter, having long suspension travel, high ground clearance, and rugged construction with little bodywork and no fairings for less damage in spills. Wheels (usually 21" front, 18" rear) have knobby tires, often clamped to the rim with a rim lock.

There are specialized motorcycles for a variety of off-road motorcycle sports:

• Motocross — Such bikes (once called "scramblers") are raced on short, closed off-road tracks with a variety of obstacles. The motorcycles have a small fuel tank for lightness and compactness. Long-travel suspension allows riders to take jumps at high speed. Motocross engines are usually single-cylinder two-stroke or four-stroke units, which vary in size from 50cc up to about 650cc. Motocross sidecar outfits have bigger engines, usually four-stroke and often twin-cylinder. Motocross bikes are also used in freestyle motocross.
• Enduro — A modified and road-legal motocross bike, having the addition of a horn, lights, effective silencing and a number plate. Enduro riders compete over a longer course (which may include roads); and an enduro event may last between one day and six days (such as the International Six Days Enduro). Some enduro events (known as "multi-lappers") are held on rather shorter circuits, not unlike scramble tracks. "Multilappers" are especially popular with novice riders.
• 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.
• Trail — A trail bike is a dual-purpose bike, made for on-road and recreational off-road riding. A trail bike may resemble an enduro bike, but since a trail bike is not intended to be used for competition, it may be less rugged, and equipped with dual-purpose tires and with more road legal equipment, such as indicators, mirrors and extra instruments.
• Trials — Trials riding is a specialized form of off-road competition testing balancing skills and precision rather than speed. For a trials bike, low weight and crisp throttle response power are the priorities, so trials bikes tend to have a small (125 cc to 300 cc) engine, with two-strokes being common. During the trial, the rider stands on the footpegs, so a trials bike will have only a vestigial seat, or no seat at all. Fuel tanks are very small, giving a very limited range.
• Track racing — High-speed oval racing, typically with no brakes, nor rear suspension. The engines, fuelled by methanol, are long-stroke four-stroke singles, such as JAP and Jawa. They have at most two gears. Some types, such as speedway, and grass-track bikes, are designed to take left turns only.

Motorcycle Rider Postures

The motorcyclist's riding position depends on rider body-geometry (anthropometry) combined with the geometry of the motorcycle itself. These factors create a set of three basic postures.

• Sport – the rider leans forward into the wind and the weight of the upper torso is supported by the rider's core at low speed and air pressure at high speed (e.g., above 50 mph (80 km/h)). The footpegs are below the rider or to the rear. The reduced frontal area cuts wind resistance and allows higher speeds. At low-speed this position throws the weight of the rider onto the arms, which can tire the rider's wrists.
• Standard – the rider sits upright or leans forward slightly. The feet are below the rider. These are motorcycles that are not specialised to one task, so they do not excel in any particular area.  The standard posture is used with touring and commuting as well as dirt and dual-sport bikes, and may offer advantages for beginners.
• Cruiser – the rider sits at a lower seat height with the upper torso upright or leaning slightly rearward. Legs are extended forwards, sometimes out of reach of the regular controls on cruiser pegs. The low seat height can be a consideration for new or short riders. Handlebars tend to be high and wide. The emphasis is on comfort, while compromising cornering ability because of low ground clearance and the greater likelihood of scraping foot pegs, floor boards, or other parts if turns are taken at the speeds other motorcycles can more readily accomplish.

Factors of a motorcycle's ergonomic geometry that determine the seating posture include the height, angle and location of footpegs, seat and handlebars. Factors in a rider's physical geometry that contribute to seating posture include torso, arm, thigh and leg length, and overall rider height.

Vintage Car

A vintage car is, in the most general sense, an old automobile, and in the narrower senses of car enthusiasts and collectors, it is a car from the period of 1919 to 1930. The vintage era in the automotive world was a time of transition. The car started off in 1919 as still something of a rarity, and ended up, in 1930, well on the way towards ubiquity. In fact, automobile production at the end of this period was not matched again until the 1950s. In the intervening years, most industrialized states built nationwide road systems with the result that, towards the end of the period, the ability to negotiate unpaved roads was no longer a prime consideration of automotive design. In today's terms, a vintage car is defined the same as a classic.

Cars became much more practical, convenient and comfortable during this period. Car heating was introduced, as was the in-car radio. Four-wheel braking from a common foot pedal was introduced, as was the use of hydraulically actuated brakes. Power steering was also an innovation of this era. Towards the end of the vintage era, the system of octane rating of fuel was introduced, allowing comparison between fuels. In 1923 the gasoline additive Ethyl made its debut at the Indy 500 that resulted in a boost in octane from the 50's to the 80's In the United States drive-in restaurants were introduced as well as suburban shopping centers and motels.

Green Vehicle

A green vehicle or environmentally-friendly vehicle is a road motor vehicle that produces less harmful impacts to the environment than comparable conventional internal combustion engine vehicles running on gasoline or diesel, or one that uses certain alternative fuels. Presently, in some countries the term is used for any vehicle complying or surpassing the more stringent European emission standards (such as Euro6), or California's zero emissions vehicle standards (such as ZEV, ULEV, SULEV, PZEV), or the low-carbon fuel standards enacted in several countries.

Green vehicles can be powered by alternative fuels and advanced vehicle technologies and include hybrid electric vehicles, plug-in hybrid electric vehicles, battery electric vehicles, compressed-air vehicles, hydrogen and fuel-cell vehicles, neat ethanol vehicles, flexible-fuel vehicles, natural gas vehicles, clean diesel vehicles, and some sources also include vehicles using blends of biodiesel and ethanol fuel or gasohol.

Vehicle emissions contribute to the increasing concentration of gases linked to climate change.  In order of significance, the principal greenhouse gases associated with road transport are carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O).  Road transport is the third largest source of greenhouse gases emitted in the UK, and accounts for over 20% of total emissions,  and 33% in the United States. Of the total greenhouse gas emissions from transport, over 85% are due to CO₂ emissions from road vehicles. The transport sector is the fastest growing source of greenhouse gases.