A gas-sipper is an extremely fuel efficient vehicle which uses a minimal amount of gas. Vehicles like mopeds and motorcycles are usually gas-sippers by nature, and some small cars are also considered to be gas sippers, especially cars which utilize hybrid technology. In many regions of the world, the vast majority of cars on the road are gas-sippers, due to high gas prices or concerns about the environmental impact of driving, and many auto manufacturers compete to design the most fuel-efficient vehicles.
The opposite of a gas-sipper is a gas guzzler, a car which uses a lot of gasoline. Gas guzzlers are typically very large and high powered, although some are simply small but poorly designed cars which are not built for maximum efficiency. In some regions, gas guzzlers are heavily frowned upon, and some governments have a form of guzzler tax which is designed to penalize car owners who purchase gas guzzlers.
Historically, periods of increasing fuel prices have been accompanied with a growing consumer demand for gas-sippers. Such periods are often marked by technological innovation as car manufacturers struggle to meet the demand for more efficient fleets. The price of gas-sippers may rise dramatically in response to the perceived demand, with consumers justifying their high priced purchases with the logic that their savings on gas will more than make up for the cost of the gas-sipper.
Unfortunately for citizens in nations where gas prices are typically cheap, it usually takes a few years for car manufacturers to roll out a fleet of gas-sippers, so consumers often feel the crunch for some time before cars are made available to them. The market for used gas-sippers in these situations can become almost stratospheric, as car dealers and private citizens realize that people are willing to pay a premium for a gas-sipper.
Scooters, mopeds, and motorcycles are generally the most fuel-efficient, simply because they are so small, requiring less power. However, some people need full sized cars, for a variety of reasons, so a number of manufacturers make gas-sipping lines of cars which are smaller than their regular lines. Often, companies tout the small size as an advantage, rather than a design concession for purposes of fuel economy; small cars are easier to park, for example, and generally easier to handle than large cars. While people sometimes complain about the small size of a new gas-sipper, they often find themselves getting used to it after a few weeks of driving and appreciating the decrease in gas bills.