Automotive fallacies

These are some common, generalized beliefs concerning automobiles that I feel need to be corrected:

1) Gas engines burn gas.
While gas is consumed by gasoline engines, it is air they burn to make power - not gas. Oxygen is the primary explosive force in a gas engine. Gasoline is the chemical catalyst that allows the oxygen to be ignited without filtering out all the other chemicals from air to form pure oxygen. If you increase the ratio of gas in an engine, making it "richer", you get less power, not more. If you reduce the gas ratio, making it "leaner", you can get a little more power but a lot more heat which can damage the engine. To make the best power an engine's air/fuel ratio needs to be properly adjusted in relation to the physical components of the engine.

Essentially, one can think of the internal combustion engine as an air pump. It sucks air in, causes it to combust, transmits combustion into rotational force, blows the air out and repeats the process. The best way to make more power is to allow the engine to breathe and exhaust with the least amount of restriction. I'll say it again: Horsepower is not gained through guzzling gas, it is gained by allowing the engine to burn more air with less restriction.

2) Horsepower matters?
Horsepower does not exist, at least not in a physical sense. It is a calculation based on torque and rpm. Specifically: HP=(TQ*RPM)/5250.

Torque is real. Torque is the amount of physical twisting force that the engine exerts at a given rpm. RPM stands for Revolutions Per Minute, or how fast the engine's crankshaft is spinning. The more rpm (more speed), the more torque is multiplied (work done more often).
Engines are typically tuned to deliver maximum torque at an rpm appropriate for their usage. Truck engines tend to develop peak torque at lower rpm, sacrificing high-rpm torque, so they can haul heavier loads without needing to rev the engine to high rpm all the time. Race cars tend to develop peak torque at higher rpm because they want maximum horsepower and are willing to sacrifice the ability to accelerate from a slow speed while hauling more weight.

3) Big engines use more gas.
This is false. Moving weight is the primary cause of gas consumption. Moving weight requires horsepower; the more weight, the more horsepower is required to accelerate that weight. If said vehicle is equipped with a small engine, that engine will need to rev to a higher rpm in order to produce enough horsepower to accelerate the vehicle (see #2 above) than if it were equipped with a larger, more powerful engine. This means that the smaller engine has to work harder and the driver must use more throttle than with the larger engine. A smaller-engined vehicle will often have a poorer mpg/hp ratio when towing or accelerating than a larger-engined version of the same vehicle. However, smaller engines require less fuel to idle. In situations when the driver will need less horsepower, like stop-and-go or medium-speed highway driving, the smaller engine will often have an advantage.

If any one characteristic of a vehicle could be blamed for using gas, it is weight. Luxury items like stereo speakers, power seats, automatic transmissions, air conditioning, all wheel drive systems, navigation systems and DVD players and safety equipment like airbags, rigid crash structures and backup sensors all add weight - and a lot of it! It is not uncommon for a half ton (often 1/4 of the vehicle's mass) of a vehicle's weight to be caused by adding optional luxury and safety equipment. I am not saying this equipment is wrong or evil, I am simply stating that it is incorrect to blame the size of the engine as the primary source of gas consumption. Convenience and safety cost.

4) Powerful engines pollute more than smaller, weaker engines.
This is completely false. The efficiency of an engine and the efficiency of it's pollution control devices determine it's emissions. Smaller, lower horsepower engines are most often used on entry-level vehicles or as base engines in mid-level vehicles. For cost reasons, manufacturers cannot equip inexpensive vehicles with engines as efficient as those found in expensive vehicles. This means that often the most powerful luxury vehicles, that consume more gas (like the BMW 7-series), are cleaner than cheap low-power vehicles (like the Geo Metro) that are most often believed to be less polluting. Did you know that the circa-1999 495hp Ferrari 550 Maranello pollutes no more than a 120hp Honda Civic?

5) More emissions controls are necessary to save our environment.
When I was in high school during the 80's in Los Angeles we had 1st-stage smog alerts about every other week during the spring and summer months. By the time I graduated college it was very unusual to have a 1st-stage smog alert at all. During that nine-year span there was also a visible change in air quality in the LA basin. How did this occur? Did people go outside and spray the air with Windex? Of course not. The air is cleaned by particulants being washed out by rain and the settling of the marine layer. Eventually these particulants find their way to the sea. During the 80s automobiles and industrial plants were polluting so much that pollutants exceeded nature's ability to wash them away.

This situation has dramatically changed, particularly due to advances in pollution control devices on our vehicles. It is now possible to lock yourself in an air-tight room with a running automobile and not be poisoned - although you could eventually die of oxygen deprivation as the engine uses it up (see #1 above), or from your own carbon dioxide emissions (exhaling).
Do we really need to make our vehicles cleaner than they are now? I do not think so. Emissions controls are expensive to research and that cost gets passed on to consumers. Are we really better off spending our money on making clean vehicles even cleaner, or on new safety devices like pre-crash sensors and blind-spot-sensing mirrors that will save lives?