<< Do you really think the brand of gas you buy makes a difference on the mpg you get? >>


It a way, it can. In the god-awful state of California, where the oil companies and enviromentalist wackos go hand-in-hand, the gasoline has an oxygenate called MTBE. This crap, yes crap, enables the fuel to burn cleaner, however at the loss of internal energy. Sadly, MTBE has a wonderful way of leaching out of fuel storage tanks and plain just not burning in the gasoline, so what happens is the MTBE becomes part of the eco-system, contaminating groundwater (wells), lakes, and rivers. There has been continuous protest against the addition of MTBE to fuels, but it is still there in most gasolines. Still contaminating.

Now, MTBE does not add any energy to the fuel, but rather displaces the gasoline of its own volume. So, gasoline with 10% MTBE is pretty much 90% gasoline, with the volume of 100% gasoline. It follows that you are getting only 90% of the energy you could get from each gallon of gas.

Some fuel suppliers, like 76, are using methyl alcohol instead of MTBE as an oxygenate. Here, you get a little more energy in your gasoline, than if it was straight gas.

So, it could be said that certain brands give more energy, hence better mpg than others. And Shell still uses MTBE.

During the weekend, I drove from the coast, through Palo Alto, the east bay to the central valley, and north to Sacramento. In my travels, the cheapest gas was $1.98. The most expensive, $2.38. Yeah, we are getting f u c k e d in California.