In Iowa, E10 gasoline (fuel composed of 10% ethanol and 90% gasoline and safe to use in normal engines) is typically $0.10 per gallon cheaper than 100% gasoline. However, the E10 fuel is less efficient than pure gasoline, enough so that it is noticeable over a long sustained trip – we typically drive three hours in a row to visit family and the difference in gas left in the tank is noticeable at the end of the trip.
I did some research and discovered that E10 fuel is about 3% less efficient than non-E10 fuel. So, for example, let’s say my truck gets exactly 17 miles per gallon with regular fuel. This would mean that it gets 16.49 miles per gallon with E10 fuel.
As I mentioned earlier, E10 fuel is typically $0.10 per gallon cheaper than 100% gasoline here in Iowa, so is it cheaper to use E10 fuel or regular fuel in my truck? Current gas prices are $3.29 per gallon for E10 fuel and $3.39 per gallon for regular fuel, so we divide each of those by the respective miles per gallon I get to find out that the difference between the two is microscopic: $0.1994 per mile for “normal” gasoline and $0.1995 per mile for E10. Thus, the price difference is completely negligible and you have to consider other factors when determining which to use (environment, octane, etc.).
What can we learn from this, especially if we look outside of Iowa’s borders?
First, there is a real difference between 10% ethanol blend fuel and non-blended fuel. The non-blended fuel is simply more efficient than the ethanol-blended fuel, as I’ve noted both by research and by observation. If you can get both E10 and regular fuel at the same price, the regular fuel is the better choice.
Second, the difference in gas prices in most areas even outside Iowa brings them close together in terms of cost per gallon. This is mostly because ethanol costs about $1.20 a gallon to produce, and thus a E10 mixture reduces the price of the gas by just a few percent – almost equivalent to the lack of fuel efficiency.
Third, the environmental issue, at least in this comparison, is negligible. The E10 is better per gallon for the environment, but you get fewer miles out of that gallon, so in the end, the benefit becomes very tiny. Don’t let environmental issues sway you, at least not until E85 comes into wide adoption and engines designed to use E85 (or pure ethanol) are in use. When that happens, then the ethanol will be as efficient as gasoline and much more friendly to the environment.
To summarize, if you have a normal car, the environmental and cost benefits of 10% ethanol blend gas are negligible, and if you can get normal gas at the same price, go for the normal gas. However, when E85 or pure ethanol engines break into the mainstream, they’ll have engines that are designed to run optimally on ethanol, at which point you’ll be much better off using those in terms of both cost and environment.