Considered as everyday tools, our cars have become cocoons of safety, comfort and practicality, but how much do they affect the environment? Here are some pointers to see how green our cars really are.

Cars began as steam powered vehicles, cumbersome, impractical and slow, in 1796 according to records in several automotive clubs. It wasn’t until two inventors, Gottlieb Daimler and Karl Benz, turned a small internal combustion engine into a “practical” vehicle, the Benz Patent-Motorwagen, with a 2 hp engine and a top speed of 16 km/h with seating for two, that the car industry truly came alive.

If we look back now, we can only look in wonder as we see how technology has evolved. Now, we focus on how many horsepower we get, the quality of our electronic navigation system, and how we can diminish the bumps on the highway with adaptive suspension.

Now, with the ever changing times that are ahead, we also have to ask ourselves, how green are our cars?

Before we get into science to answer this and other questions, we have to get some facts straight from the get go. Firstly, we will only talk about diesel or petrol engines; electric cars, hybrids, ethanol, vegetable oil and all the other means of transportation will be put aside for another article. Also, here some quick, interesting facts to get acquainted with the article:

Facts:

-Your car pollutes, no matter what, your car uses petrol or diesel; both are combustibles that have residues, hence they pollute. Sorry.
-The more your engine idles, the more inefficient and pollutant it becomes. Traffic jams are the main source of vehicle pollution in crowded cities.
-The only reason we use combustibles as a main power source is because in the early years it was discovered that it was faster than other engine designs.
-If you are going downhill, putting your car into neutral will actually cause it to use more fuel as it has to inject fuel to keep running, leaving it in gear will not consume fuel as the gear itself keeps the engine running.
-Pollution doesn’t only come as emissions, one of the factors considered now by organizations around the world is noise. Loud mufflers be gone, except for the import and hot rod Tico hipster scene!

So, let’s get more into the science of the engine under your hood. Be it diesel or petrol, both engines pretty much operate under the same principle, a combustible substance (fuel) comes in, it bursts under heat, pressure or both, and creates energy, the energy drives a shaft and the shaft moves the tires.

Since both use the same principle, both pretty much have the same emissions, consistent of Nitrogen (N2), Carbon Dioxide (CO2) and water vapor (H20 in gas form). These three aren’t that bad, they’re the “good” guys of pollution, N2 is the major component of air and passes right through the engine; CO2, though considered responsible for global warming, isn’t dangerous in low amounts and water vapor is generally sent to the atmosphere with no negative effects.

The bad guys (no quotes needed here) are Carbon Monoxide (CO), Hydrocarbons (basically unburned fuel coming from your engine) and Nitrogen Oxides (NOx). CO is poisonous and odorless –a deadly combination–, Hydrocarbons are flammable and toxic and NOx contribute to acid rain, inflammation of mucous membranes and smog.

Ok, it all sounds too tragic, but be calm. The bad guys are usually expelled in very low amounts, reduced by the catalytic converter in your car. This piece of engineering is responsible for filtering the exhaust fumes coming from your car and rendering the bad guys low enough to be acceptable according to standards such as the EPA, EU Environmental Protection and so on.

How about numbers?

If you want to know what actually your car is doing to the environment, the following data is simple to understand. When you take your car to the yearly revision in RTV, you will get a sheet of paper explaining whether it passed the test or not. In it, you will find this:

-COR and COA: CO emissions in your car when idling and when accelerated
-HCR and HCA: Hydrocarbon emissions in your car when idling and when accelerated
-CO2R and CO2A: Carbon dioxide emissions in your car when idling and when accelerated.
-OPACIDAD (opacity, for diesel engines): the amounts of emissions coming from your diesel car that cause opacity in the air.

It is important to highlight that the information provided on new cars usually refers to when the car is being accelerated, so now you know what to ask for. Dealerships will gladly provide information on emissions on their new cars. Here is data on some new cars entering the Costa Rican market and their emissions:

-Nissan Versa 1.8L: 128 gr/km CO2
-Volkswagen Jetta 2.0L: 159 gr/km CO2
-Citroën C3 Diesel 1.4L: 98 gr/km CO2
-BMW X5 Diesel 3.5L: 198 gr/km CO2

As you can see, emissions depend a lot on technology, engine size and fuel type. The BMW for example has an advanced system that injects urea to purify the diesel exhaust and the Nissan Versa utilizes gasoline direct injection to lower emissions and increase mileage. Be sure to inform yourself on all these aspects before you put your money down on a car and you can drive with a clean state of mind.

What can I do to make my car greener?

A simple rule of thumb dictates pollution when it comes to cars: the less fuel it uses, the less it pollutes. Cars with big engines but big technology can have fewer emissions than smaller engines with simpler designs because their efficiency is higher. Whether your car is new or old, big or small, here are some pointers for a greener drive:

-Don’t drive short distances: driving just a mile or two can be changed for a stroll or a short bike ride, if safety allows it.
-Service your car regularly: the fact is this helps in every aspect, you’ll be safer, your car will have better performance hence less pollution, and its value will maintain for longer periods of time.
-Keep your tires in check: pressure differences can cause irregular wear on the car, increasing fuel consumption.
-No heat? No A/C: Air conditioning can increase your fuel consumption in 10%, if you can deal with the heat then turn it off.
-Extra pounds: Shed off unnecessary weight as luggage, equipment, loaded racks and such when you don’t need them will increase the fuel consumption.
-Speed kills your wallet: don’t pretend you’re a Rally driver, sudden acceleration will definitely send your mpgs down. Be gentle.
-Turn it off: if you’re in a traffic jam, mindlessly wasting time, don’t waste fuel! Turn off your car if you see that you will be stationary for minutes. In some European countries, idling cars can be ticketed and considered pollutants, oh my.

Now you know some facts about greener driving and I hope you use them and make your driving habits less polluting. In upcoming articles, the cars that we review will include emissions as well as green tech stats.