Alternative Fuels Auto Emissions

Alternative fuels are fuels that are made from something other than petroleum. There are 5 main alternative fuels used today. Each type of fuel has its advantages and disadvantages. The big advantage to all of them is that they create less pollutants and/or greenhouse gasses than gasoline or diesel. Yeah!!! Using alternative fuels can also make the world less reliant upon petroleum as our primary source of powering cars. Yeah again!! Another cool feature of getting a car that runs off alternative fuels in the US is that the US government gives tax breaks if you buy a qualified alternative fuel based car. Triple yeah!!

Here are the 5 main alternative fuel types:


There are two main types of ethanol fuel sold for use in cars in the US market today.

E10, which is also called gasohol, is a mixture of 10% ethanol and 90% gasoline. E10 is approved by most manufactures to be used in their gasoline powered cars (be sure to double check yours before you use E10).

E85 is what most people are talking about when they say ethanol. It's a blend of 85% ethanol and 15% gasoline. E85 can't be run in just any car. You need a car called a FFV or Flexible Fuel Vehicle. This type of car can run off E85, gasoline, or any combination of the two. So you can use E85 when available, but can also use gas in areas where E85 is no offered. There are many FFVs offered by various car manufacturers.

E85 has a lot of great advantages like lower air pollution, reduced engine knock, it can be produced locally, and the added cost to the car engine is not too bad. E85 is becoming more readily available. Some places Ethanol is cheaper than gas and some places it is more expensive. Also, in most cases power delivered from the engine is not reduced with E85.

Disadvantages to E85 include the need for an FFV, availability, and that it gets less miles per gallon (around 25%), making it more expensive than gas in many cases.

Natural Gas

Natural gas to run a car? Are you sure? Yes, we are. In 2008, Honda released the Civic CNG. This environment friendly car runs off of Compressed Natural Gas (CNG). Although, the Civic CNG is one of the few new cars to run off this form of alternative fuel, some existing cars can be retrofitted to run off of natural gas.

Natural gas as an alternative fuel has some excellent advantages. First it is very environmentally friendly. Cars running off CNG produce less smog pollutants and less greenhouse gasses. Also, natural gas can be less expensive than gasoline.

On the down side, there aren't a lot of car options, cars that run on both CNG and gasoline have to have big tanks using up cargo space, and you get fewer miles per fill up using natural gas. But it's worth it to save our planet!


Hydrogen may the alternative fuel of the future. It's a bit less developed than some of the other fuels, but it has some great potential. Hydrogen is often used to power fuel cells for electric cars, but it can also be used to power internal combustion engines.

Hydrogen has the great advantage of producing little to no pollutants or greenhouse gasses. What a deal! It can also be produced locally, easing the reliance on gasoline and oil.

Technology still needs to advance some for hydrogen to become a standard fuel source. It's still very expensive, the cars using the fuel cells are pricey, hydrogen itself is pricey, and hydrogen is not readily available to purchase.


Like many alternative fuels propane produces less pollution than gasoline. Also, a high percentage of propane used in the US is produced locally.

Propane has not taken off in commercial vehicles lately, however. There hasn't been a commercially built propane car since 2004. This implies that other alternative fuels are gaining popularity over propane. Propane is still a viable option to gasoline and should be considered. Existing gasoline cars can be retrofitted to use propane.


Biodiesel is an interesting alternative fuel to gasoline. It has the advantage of being produced from many sources including recycled greases from restaurants. In general, Biodiesel produces less pollution than gasoline, but it does produce more nitrogen oxide.

Biodiesel comes in all sorts of blends of pure biodiesel and petroleum based diesel fuel. They are denoted with a B and then a number representing the percentage of biodiesel that is used in the blend. For example, B5 is 5% biodiesel and B100 is 100% biodiesel.

It should be noted here that most automakers do not warranty their engines if you use a blend with more than 5% biodiesel. So be sure to check the blend percentage as well as check with your automaker to be sure this fuel is safe!

Biodeisel is also nice because its biodegradable, safer to handle than gasoline, and it's non-toxic (in it's pure form).

The viability of biodiesel as a reliable alternative fuel is still being investigated by car manufacturers, engineers, and scientists, but the future looks bright.

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Consider alternative fuels

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