Automobile

Automobiles are a common form of transport in much of the developed world. Also known as cars, they are generally large, multi-ton wheeled carriages powered by combustion engines. These vehicles are capable of travelling long distances at a respectable speed. Unfortunately, most automobiles burn fossil fuels, a non-renewable resource that pollutes the atmosphere. The carbon dioxide emissions from these fuels also contribute to global warming.

Brief history
The first automobile was designed in 1886. By 1908, cars were being mass produced, and soon the automobile's body style began to diversify (e.g. hatchbacks, sedans, wagons, etc.). Large cars built on truck chassis, called "sport utility vehicles" (SUVs), became popular in the U.S. during the 1990s as status symbols. These SUVs suffer from safety issues &mdash; particularly in collisions with people on bike or foot &mdash; and are very inefficient. Fuel price increases in 2007 and 2008 led the American public to stop buying large numbers of SUVs, which created tremendous problems for American automobile manufacturers, which had made selling huge numbers of them the centerpiece of their financial strategies.

Car woo
Automotive woo is the promotion of certain goods and services that ostensibly improve one's driving experience but are not founded in science. Though this fact rarely ever stops the petrol heads from trying it anyway.


 * Special spark plugs make your car run better:
 * Actually, new spark plugs often make your car run better. The correct ones (i.e., the type specified by the manufacturer) make it run best. Proper gapping is also necessary, as too small a gap or too large a gap can cause misfiring.
 * A quart of magic goo will clean and preserve your engine or transmission, improve operation and fix minor problems:
 * Proper engine oil, lubricants, conditioners, and detergents work best, and run no risk of engine damage. Note, however, that these products might mask the symptoms of a problem without actually fixing it. A number of these so-called "engine treatments" such as and Slick 50 have previously been investigated by the Federal Trade Commission for making unsubstantiated claims about improved engine performance and reliability.
 * Inflating your tires with nitrogen will make it talk funny do some magical stuff:
 * Race tires are filled with nitrogen because the extreme temperatures caused by doing sharp turns at 300 km/h turns water and oxygen into chemical reactives that can degrade rubber; on a normal civilian car that rarely does anything beyond 120 km/h, this effect is negligible.
 * For similar reasons, aircraft tires are filled with dry nitrogen. Unless one is in the habit of using friction with the pavement to spin the wheels from zero up to a comfortable margin above aerodynamic stall speed (which is mighty flippin' fast in the case of most road vehicles, on the order of space shuttle re-entry speed) the benefit is negligible.
 * Inserting a stamped metal "air twister" into the intake will increase mileage
 * Without going too deep into math and engineering reasons, no, they won't. Simply, if a $1 stamped piece of metal could increase fuel mileage by any significant amount, every manufacturer would already install them into new automobiles.
 * Using premium grades of fuel will increase power:
 * This applies if and only if your car is designed to run on premium; in that case, lower octane fuel will reduce your power and economy. In many older performance engines (and even modern very high performance applications), running regular unleaded can cause problems such as pre-ignition, or "knocking". If a car requires, or even recommends premium, it will say so in the owner's manual, and usually on the gas cap as well. Otherwise, "premium" just costs more for no benefit. Odds are, if the car isn't a high performance or muscle car, it's designed for regular unleaded gasoline. Some newer cars recommend premium, but can still run fine on regular unleaded, albeit not at peak performance.
 * Send $20 and we'll send you blueprints for converting your car to run on nothing but water!
 * You get some hypothetical BS; none of these actually work. You would have to produce incredible amounts of electricity to run most of these designs, and where would you get that power from? THAT'S RIGHT, from the engine - so in the worst case they would explode or light your alternator on fire, and at best do nothing. You're better off sending that money to the ad underneath it selling instructions for building your own flying device out of a lawnmower engine.
 * A really big exhaust will make it go faster!
 * While increasing the exhaust diameter of the entire system can indeed increase power (It is, in fact, one of the first modifications generally carried out by those seeking a faster car), and can even increase fuel economy, simply putting a large muffler on the end of your stock pipe does nothing. Also, once you reach a certain point, increasing your car's exhaust pipe diameter does nothing.
 * Our fuel is better than their fuel because it's enhanced with (fill in the blank: some no-knock compound, magic pixie dust, a tiger)... etc. etc.:
 * Doubtful unless the additive improves the octane rating, although even this has dubious benefits unless the car is designed to run on premium. Good ole hooch (ethanol) is one of them: the octane rating of pure C2H5OH is 106. One rarely mentioned factor that can improve fuel quality is age. As fuel sits in the tank, condensation increases the amount of water present in the fuel. Therefore, freshly pumped fuel will be of superior quality to that which has sat in the tank for ages. Also, modern gasoline ages quite rapidly, and condenses junk on fuel system components, rendering them inoperable. If a motor is to sit for a while without being run, fuel stabilizers (about the only magical bottled product that actually works) are advised to prevent "varnishing", and the build-up of condensation.
 * Detergents are another useful additive which prevent deposits on fuel injectors and valves. All fuel sold in the USA meets a minimum EPA standard for detergent content.  An alternative standard developed by BMW, General Motors, Honda, Toyota, and Volkswagen known as Top Tier contains higher levels of detergents and such fuel is recommended by these automakers.
 * If you run a (gasp!) diesel car (which already do have darn good thermodynamic efficiencies and mileages), be aware of the diesel contaminants, such as diesel bug. That is a bacterium which consumes diesel fuel and produces nasty black goo, contaminating fuel lines. Using biocides and emulgators, such as StarBrite, will improve your mileage - by simply keeping the fuel lines clean.

Fuel woo
A common form of automotive woo is fuel economy woo: devices that claim to improve fuel economy. It becomes more common during temporary spikes in prices of fuel (1974, 1980, 2008). Most vendors of these products also claim an increase of power "up to" some percentage.

Examples:


 * Adding standard magnets to your fuel line
 * Shoving a dildo with some flashing lights into your cigarette lighter
 * Attaching a box with a crystal inside it anywhere on your car
 * Adding "HHO gas" (from an underhood electrolyser) to the intake will improve economy by completely burning all fuel. As stated above, these devices get their power from the engine in the first place, so the tuning on these devices would have to be so incredibly precise, as to not be worth it at all. That is, if the car has unburnt fuel to begin with.
 * Homebrew "water injection" devices to add to your carburetor were promoted during the late 1970s "energy crisis", in such magazines as The Mother Earth News. The fuel economy improvement from these is so negligible, why bother? In order to see any real improvement, you would have to retune the engine to run extremely lean, bypass the radiator to keep in the heat, and pump in some serious amounts of water. All of which would rust the whole thing to junk in about 10,000 miles after you turned your car into a tea kettle. Water or methanol injection is used in some high powered turbo or supercharged cars, as well as a number of WWII aircraft engines, to cool the charge in the cylinders, but people doing this are not concerned with efficiency so much as getting the maximum power out of their motors without overheating them. To be precise, the water injection works as a chemical intercooler (nitrous oxide works as chemical supercharger): it cools down the fuel-air mixture, increasing its density and decreasing its volume. It is of little use on freely breathing engines without blower or turbo.

For more, see the EPA's "Gas Saving and Emission Reduction Devices Evaluation".

Legitimate techniques
"Hypermiling" is the obsessive-compulsive practice of utilizing driving techniques to maximize fuel economy. While unlike any of the above this does improve fuel economy, sometimes radically, it can result in some dangerous driving practices. Hypermilers tend to be nuisances on the road, especially if they aren't paying attention to anything but obsessively trying to squeeze as much kilometreage as they can out of that last drop of petrol. Truck drivers are sick and tired of you four-wheelers drafting right behind them, so cut it out already.

There are much less expensive ways to improve fuel economy that don't demand any modification, nor any dangerous driving practices. Most of these are free:


 * Check tire pressure regularly. It's harder to drive with limp tires than firm ones due to flatter tires contributing to more friction with the road. Also, low rolling resistance tires do cause a measurable increase in fuel efficiency, however this comes at the cost of traction. They would be fine in a dry climate with no snow, but if you have heavy rains or serious winters, the small fuel savings are not worth sacrificing the potentially life-saving traction.
 * Keep your engine "tuned" with appropriate maintenance intervals, and run the lightest oil weight your climate and engine can handle. A good synthetic will allow you to run a lighter weight oil and not blow up your motor. This can help your engine remain efficient at converting fuel to motion. This is a slight increase, but 5W-30 costs no more than 10W-30.
 * Drive slowly, but keep pace with traffic. After all, there is a special place in hell for those that drive slower than the rest of the traffic in the farthest left lane in the freeway. Stay in the right-hand part of the freeway so cars won't drive around you and put them in danger. Basic physics states that it takes more energy to accelerate to a higher speed, and the power required to overcome air resistance increases as the cube of velocity.
 * If you don't drive slowly, by God's love try at least driving at a constant speed. A combustion engine works most efficiently at a constant rate of revolutions. If your car has cruise control (most cars nowadays do), use it as much as possible and use it also on accelerating and decelerating the car.
 * Use the pedals gently. Accelerate slowly if possible, and get out of the lower gears as soon as possible, while downshifting as little as possible. You don't need to pass everyone, and the world won't end if you lose 5MPH going up a hill or some cars pass you.  Coast down and brake gently if possible (instead of keeping the throttle pressed until you're barely at the intersection).
 * Do not carry excess weight in your vehicle. Basic physics also dictates that lighter objects (i.e., objects with less mass) take less energy to accelerate to the same speed. This includes the wings on your car, even if they look cool. And while you're lightening up the car, make sure you also maintain your weight.
 * Buy smaller, lighter vehicles; again, lighter object, same acceleration, less energy used.
 * Buy a newer model vehicle if possible, as developments in engine technology are delivering ever greater efficiency with no impact to the performance (and perhaps more importantly, safety) of the vehicle.
 * Get a manual transmission car. The manual not only gets better mileage in many cars, but it's lighter (lower weight = better MPG) and typically has lower maintenance costs. Once you get the hang of a manual, it's a hell of a lot more fun than an automatic. In countries where automatic transmissions are normally in use this may increase the cost of your insurance, however, as drivers inexperienced with manual transmissions are at risk of rolling backwards on hills when proceeding from a stop.  While a manual transmission is more efficient in older cars, modern cars equipped with 8 and 9 speed automatics, along with, are typically more fuel-efficient than the same car with a manual transmission. The greater number of gears (or with a CVT, the lack of gears) allows the engine to operate in the most efficient range of its  more of the time, increasing miles per gallon and overall efficiency.  That being said, manual transmissions remain significantly cheaper to service and maintain over the life of the car.  They are also the best theft-deterrent security system available.
 * Once you have acquired a manual transmission car, learn to do motor braking. That is to switch to a smaller gear to slow your vehicle down instead of pressing the brake pedal. It is especially useful on curves as it will improve your control of the car as well. (This form of downshifting is good, not bad.)
 * Try avoiding pressing the brake pedal whenever possible; instead learn to predict your speed and adjust it by the gas pedal. A brake is a device which converts mechanical energy into heat (except, of course, in hybrids).
 * Take off the roof rack when not needed. It improves the aerodynamics a lot.
 * If you're on the highway or otherwise driving at high speeds for a long distance, it's probably a good idea to keep the air conditioning on and keep the windows closed to improve aerodynamics (especially if your vehicle is aerodynamic to begin with) and therefore use less gas.
 * In wintertime, use the electric engine block heater whenever possible. If the weather drops below zero (Celsius or Fahrenheit, does not really matter), warming up the engine may mean doubling your fuel consumption within the first fifteen minutes of your ride if the block has not been pre-heated. Note that combustion engines work really inefficiently when cold. Keep your car in a warm garage as much as possible. If you live somewhere where it doesn't freeze much, warming up your car is unnecessary and only wastes gas; don't look like an idiot in front of your neighbors.
 * A note on hybrids. Hybrid cars are not bad. They do get good mileage, particularly in stop-and-go driving (where their regenerative brakes gain maximum advantage), and have been proven to be as reliable as your standard internal-combustion-only car. However, their prices are higher and it is unlikely you will make up the costs in fuel savings over the life of the car. If you want to help the environment, hybrids are a reasonable option, but if you simply want to save money, a diesel or a small, light car is a better bet. If you really want to do both, electric cars are a real option now.
 * There are plans out there for a way to set up a variable resistor in series with a mass air sensor, to make your engine run much leaner when not requiring much power. This is only for the technically proficient.
 * If you're moving your living quarters to another place, find a place that is close to civilization. It's far more ecological and economic when you can just walk to the grocery store than when you have to drive 10 kilometers to get to the nearest supermarket.
 * The most effective thing you can do (in a car, anyway): Carpool. Having a passenger doubles your "people miles/gallon", or halves your "liters/100 km-people".  Two passengers triples pm/g, and so on and so forth.
 * And the most effective way to save on gas: Don't drive. Buy a bike, or walk. You don't need a car to go two blocks! Public transit is often cheaper and sometimes faster than driving. Outside the US, anyway, as in the US, your mileage may vary if you live in suburbs. And if you are fond of adrenaline and high speeds, there are roller coasters and high speed rail for that. If you really need your shot of adrenaline and need to be in control of the situation, try.

Spoilers
A fun questionnaire:

1. A six-foot fiberglass spoiler on the back of your car makes it:
 * (a) faster
 * (b) slower

Take your time.

The entire purpose of a spoiler (really a 'wing') is to use forward motion to create down force. Down force pushes the car down onto the road, thus increasing the mechanical grip of the tires. Wings also increase the car's drag, meaning more power is needed to push the car through the atmosphere. This is a good thing in many race situations, where the high-powered, lightweight cars would quite literally fly off the track due to air building up underneath them, in the absence of any countervailing force. However, on the road, a large spoiler is unnecessary, considering most cars cannot reach the speeds required for it to be effective, and even the few that could would be endangering their driver, the driver's license, and everyone else on the road by driving at such irresponsible and excessive speeds. Finally, since they are unnecessary in everyday use, the weight, drag, and down force that a wing adds to the car can slightly negatively impact fuel economy.

While most people call all such things spoilers, really a spoiler sits flush on the back of the car and deflects air upward, spoiling the airflow from tumbling down behind the car immediately, and creating a bit of drag force. A 'spoiler' that allows air underneath it is actually a wing, with a cross section upside-down compared to an airplane wing. Just as an airplane wing (with the trailing edge lower than the leading edge and the bottom relatively flat compared to a rounded top) creates lift when moving through the air at high speeds, an automotive wing with the trailing edge higher than the leading edge and the top relatively flat compared to a rounded bottom does the opposite, pressing down on the back of a car.

A race car wing is precisely engineered in a wind tunnel to provide an exact level of down force due to this wing profile, matching the car's specific aerodynamics and tire adhesion. A street wing is designed to look cool to those who don't know any better. If you are a professional racer, by all means, put that spoiler or wing on. It may save your life. If you're a boy racer revving your car at stoplights, save your money. This goes double if you have a front wheel drive car like a Honda Civic. In the unlikely event your aftermarket wing actually did create any down force, this would cause the front end to lift slightly and lessen the grip of the front wheels. You know, the wheels that account for your steering and about 70% of your braking power.

However, on some roads where the speed limit is "how fast you can go", wings can go a long way toward improving stability at speeds in excess of 160 km/h. An example is the original Audi TT sports car that was recalled and forced to add a rather unsightly spoiler on the back due to lack of grip at high speeds.

Pollution and global warming
In the wake of widespread concern over climate change and rising gasoline prices, many American automobile-drivers have been switching over to hybrid cars and to smaller, more fuel-efficient vehicles. However, some drivers continue to buy and use highly inefficient SUVs, such as the iconic (and discontinued) Hummer, despite the economic and environmental problems that these vehicles pose.

Many products and methods exist which ostensibly improve automobile performance and gas mileage. Some of them work (e.g., smaller engines). Some of them don't (e.g., "go-faster" stripes and massive exhausts).

Deaths
In addition to the environmental impact of automobiles, their use also claims many lives each year, with approximately 3,000 deaths caused by automobile use in the UK each year. The manufacturers and motorist lobbies have managed to successfully shift at least some of the blame for these incidents onto the victims. This has been done by the setting up of motorist-lobby funded "safety charities", such as the Road Safety Foundation in the UK, which promotes cyclists and pedestrians dressing in high-visibility clothing, in addition to helmets for cyclists. Much of this promotion is addressed directly to young children, in schools.

The good news is, modern automobiles are considerably safer than they were half a century ago. Seat belts weren't even required on cars in the U.S. until 1968, let alone safety features like crumple zones, air bags, and antilock brakes. Ralph Nader's 1965 book Unsafe at any Speed was influential in getting Congress to unanimously pass the National Traffic and Motor Vehicle Safety Act in 1966. U.S. traffic fatalities were 10.4 per 100,000 persons in 2011, as compared with the all-time high of 26.4 per 100,000 persons in 1969.

For comparison, in 2013, the US government reported 32,719 "highway" deaths (any involving a car), 706 from railroad incidents, and 429 from air incidents.

Urban planning
Historically, almost all cities were compact and had as many people on as little room as possible (that's the point of a city after all); the car enabled the phenomenon of "suburban sprawl", with more and more suburbs upon suburbs (often voting conservative, to nobody's surprise) along tax-supported interstate highways. Interestingly, several entire countries have largely embraced alternatives to cars -like the Netherlands (bikes and mass transit) or Denmark (bikes).

In many countries, especially in the developed world, World War II resulted in cities that were more or less tabula rasa, so city planners could (re-)build "modern" automotive-centric cities. However, even the US — a country that was not bombed to any significant extent after 1865 — tore down many historic buildings to build freeways right through downtowns. The urban-planning community now almost unanimously views the effects of this negatively - and as a matter of fact several cities have torn down urban highways, including San Francisco, Seoul, Portland (Oregon), and Madrid. In all these cases the cities that tore out urban freeways never looked back.

Over-specification
For some reason (which may have to do with marketing) manufacturers design and construct the average car to operate on speed-unlimited German autobahns. This means that vehicles which operate within or even between urban areas in most parts of the world end up grossly over-specced for their alleged purposes of ferrying people around other places under local conditions. The higher the design speed, the more safety measures required, and the higher the cost of each individual vehicle. Go figure.

Car-free movement
The car-free movement is a bunch of hippies an environmentalist socio-political movement that aims to usher in a car-free world. The rationale behind the movement is that cars are responsible for the destruction of street life, damage to the social fabric of communities, isolation of people, suburban sprawl, inconvenience to other street-users, noise pollution, air pollution, global warming, a decent proportion of crime, and waste of energy and natural resources. Automobiles should therefore be abolished. The car-free idea is also sometimes used as a strawman position whenever someone argues that people should drive less often, or that governments should invest in infrastructure for modes of transport other than private cars, such as bikes, cycleways or public transport.

Activists in several cities organize local "car-free days". Many promote September 22 as "World Car-Free Day" annually.

Car-free zones
In some places cars are outright banned. In some cases, this can be for public safety (keeping cars away from busy streets packed with people) and other times it is to cut down on pollution levels and traffic in inner city areas. This is sometimes enforced in cities and towns with ancient architecture, where car based pollution has been blamed for accelerated erosion of historical ruins. Islands such as Sark and cities like Venice don't have cars for obvious practical reasons, such as the lack of roads.

Vehicular politics
Alternatives to car use are often treated with high degrees of suspicion among conservatives, as are higher gas taxes.

Investments in infrastructure used to be common sense in the US (after all the interstate highway system was promoted by Eisenhower and Amtrak was created under Nixon). However, federal dollars spent on anything that is not cars (like public transit or, god forbid, rail) are heavily criticized (including being labelled as "socialism") by the likes of the Reason Foundation, the Cato Institute, and Fox News. All this baseless conservative backlash against alternatives to cars sometimes forces transit advocates to get creative. For example, in 2013, transit and environmental activists managed to get a bill allowing local governments to spend gas tax revenue on car alternatives passed by framing it as an issue of local control, a favorite talking point amongst conservatives. Previous attempts at similar bills had proved "extremely controversial".

Anti-gun control talking points often invoke cars. As in, the tired argument that "Cars kill more people but no one is advocating a ban on cars". At the same time some advocate a ban on both.

Cars and terrorism
Although car bombs have been used as a weapon of terrorism since at least the 1920s (most notably by the IRA, ETA, Palestinian freedom fighters, various Islamist terror groups, the CIA, and Timothy McVeigh), the tactic of deliberately ramming a vehicle into a crowd of people became a fad among terrorists during the mid-2010s, being easier than carrying out homicide bombings suicide bombings. The 2016 Nice attack, the 2017 London Bridge attack, and the Charlottesville attack during the Unite the Right rally are some of the most prominent vehicle-ramming attacks.

Promoters of vehicular terrorism include Al-Qaeda, ISIS, and Fox News.