Tuesday, September 23, 2008

Ethanol fuel and cars

Ethanol fuel is ethyl alcohol - ethanol, the same type of alcohol as in alcoholic beverages. Ethanol fuel is one of two basic types of biofuels: biodiesel and bioethanol (some people like to call ethanol bioethanol - it sounds better from environment point of view). When used as a fuel, ethanol is commonly mixed with normal gasoline. Most standard cars can run on an up to 10% mixture of ethanol in regular gasoline (E10) without modification of the engine. E85 is mixture of up to 85% of ethanol and at least 15% of regular gasoline. This mixture is becoming increasingly common in US and Europe, but not all regular cars can use this fuel without modification. Good think is that the cost of upgrade of a modern engine to use E85 is inexpensive and is less than $100. Because of the cold start problem, the alcohol content of E85 might be reduced during the winter, to E70 in the US or to E75 in Sweden.

E85 gas station.

Today we can find variety of hybrid automobile engines that have ability to use both ethanol and gasoline; sometimes these cars are called “flex-fuel” cars. Injection principle is same with ethanol as it is with standard gasoline engine. Ethanol has less energy content than gasoline, and it is true that ethanol doesn't give so many miles per gallon as gasoline, but its advantage is that its combustion does not create as much air pollution as standard gasoline combustion does. "Total Flex" cars destined for the Brazilian market can use E100 (100% Ethanol).

Because ethanol “flex-fuel” engines and standard engines are almost the same, ethanol cars are cheaper solution than most alternative or hybrid vehicles, mainly because their building structure is in many ways the same as the one of regular engine. Ethanol can actually be cheaper in some cases than gasoline, therefore sometimes making hybrid that runs on ethanol less expensive to maintain than a standard gasoline based vehicle.

Pure gasoline vs E85 fuel consumption

Chevrolet Monte Carlo

MPG (city): 21 (11.2 l/100km)
MPG (highway): 31 (7.6 l/100km)
Greenhouse Gas Emissions: 7.4
MPG (city): 16 (14.7 l/100km)
MPG (highway): 24 (9.8 l/100km)
Greenhouse Gas Emissions: 5.9

Lincoln Town Car

MPG (city): 17 (13.8 l/100km)
MPG (highway): 25 (9.4 l/100km)
Greenhouse Gas Emissions: 9.3
MPG (city): 12 (19.6 l/100km)
MPG (highway): 18 (13.0 l/100km)
Greenhouse Gas Emissions: 7.7

GMC Yukon 1500 4WD

MPG (city): 14 (16.8 l/100km)
MPG (highway): 18 (13.0 l/100km)
Greenhouse Gas Emissions: 11.6
MPG (city): 11 (21.4 l/100km)
MPG (highway): 14 (16.8 l/100km)
Greenhouse Gas Emissions: 9.4

Full list of E85 cars and fuel consumption comparison you can find here.

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