Fuel Comparisons | mybenzguy.com

I know there has been a big push to find alternate fuel sources for vehicles in the last couple of years. Ethanol or E85 seems to have risen to the top. Look at GM and you see a lot of “Flex Fuel” vehicles in their line up. While ethanol maybe a fuel alternative, it is not as energy efficient as gasoline. You ask, what does this mean to me? Let me explain.

BTUs – Gasoline vs. Ethanol

The BTU is a measurement of heat, or energy, content that a fuel possesses. A higher BTU rating equates to a higher energy level. Regular-grade gasoline has a BTU rating of 125,000, while Ethanol has a rating of 84,600. This means that one gallon of ethanol produces approximately 2/3 the energy of a gallon of gasoline. Have you ever noticed the disclaimer “this fuel may contain up to 10% ethanol”? A gallon of ethanol/gasoline blended fuel is approximately 10% ethanol and 90% gasoline. Therefore, one gallon of gasoline contains roughly 6% more energy than one gallon of blended gasoline. While this may seem insignificant, it translates to a 25 mpg car now only achieving 23.5 mpg. The U.S. Department of Energy says that a vehicle using E85 gasoline (85% ethanol and 15% gasoline) consumes 1.4 times as much E85 as gasoline to go the same distance.

Evaporation

A gasoline/ethanol mixture results in a higher evaporation rate. Because of this, refiners are required to alter their gasoline formulas greatly based upon geography and climate. Therefore, there is no “standard” blend. One area may have a 10% blend while another has a 2% blend, resulting in a 1 mpg difference in fuel economy based upon where you fill up.

My question is, is E85 really a better alternative? It requires you to burn more to get the same result as gasoline! Something else to consider is availability. I know in the Atlanta area E85 fuel is very hard to find. Last I checked you could count the number of E85 filling stations on 2 hands. As I understand it, it is more readily available in other parts of the country.

Diesel Fuel as an alternative

Comparing diesel to gas. It has a higher BTU measurement, 147000 BTU’s vs 125000 BTU’s. Which means it is more efficient burning than gasoline. It is less expensive to refine, which is why diesel use to be less expensive than gasoline (I’ll get to more on that in a minute). It emits very small amounts of carbon monoxide, hydrocarbons and carbon dioxide, emissions that lead to global warming. Our new diesel technology reduces the amount of nitrogen compounds and particulate matter (soot) that are released. Which in the past led to acid rain, smog and poor health conditions. A big misconception is you can’t find it anywhere. Think about it though, if you aren’t looking for it you wouldn’t notice it’s availability. In reality about 94% of all freight being transported relies on diesel fuel, whether it’s by truck, train or ship. Which is why we have seen the increase in price over the last few years.

The bottom line… it is still more fuel efficient.

Mercedes-Benz diesel technology is great. It should be as we have been using them longer than anyone else in the auto industry. It is not like “grandpa’s old diesel” that is slow going, smokes like a chimney when you start it, and rattles down the road like a tank. Our diesel engines create more torque (that’s the get up and go when you hit the gas pedal) than our 5.5 liter V8’s. They are considered the cleanest production diesel engine available. Lastly, they don’t sound like a tank rumbleing down the road.

I hope this gives a good comparisson of some of the available fuel alternatives. I believe diesel technology is where it is at. It is more efficient, cleaner than before, and the engines are a little less to maintain because of the way they are built. Our SUV’s are 50 state legal emissions and our E-Class should be 50 state emission compliant next year.

I look forward to answering any questions about our diesel technology.

Adam Denault