The top tier standard was developed by a group of auto manufacturers (BMW, GM, Honda, Toyota) using tests to measure such things as deposits in engines. Top tier fuels should be better for your car. I use Shell on occasion. Other times I use Tier 2 fuels (BP, Citgo, etc.). Occasionally a tier 3. Shell isn't necessarily more expensive then the competition, so you don't necessarily have to pay more.

What I read a while back is that tier one fuels are actually supposed to clean out deposits because they contain the highest level of additives. Tier two gasolines are supposed to have enough additives (more than required) to prevent accumulation of deposits. And, tier three fuels only have the minimum required amount of additives which may not be enough to prevent accumulation of deposits. Who knows for sure?

When it comes to ethanol as fuel, it ain't all that. It is better mixed with punch.

The DOE's plan is to go from producing 5B gallons of ethanol to 60B gallons a year by 2030. Right now the U.S. uses around 146B gallons of gasoline a year! So we will still using vast quantities of gasoline. A lot of people buy into the hype and think that there's this unlimited bio fuel source just waiting to be tapped into and at just a fraction of the cost of gasoline. Keep in mind that even though the masses think gas prices are too high, ethanol won't be any cheaper. It's heavily subsidized by taxpayers (thanks to the agriculture lobby) to make it look cheaper than gasoline. Even if ethanol optimistically can be produced with an amount of energy significantly less than its energy output there are still other issues like pollution (fertilizers, pesticides), taxing of water supplies through irrigation, drought, etc.

I can see the headlines now: Iowa Drought Responsible for Fuel Shortage, President Clinton (Chelsea) Taps Strategic Corn Reserve, Petroleum Leads Maize of Options for Alternative Fuel.

As long as we have petroleum that is easy to extract we should use it. Strategically it makes sense because it forces the rest of the world to also invest in the eventuality of alternative fuels. Why wean ourselves of petroleum now so the Chinese can use it and spew out 2.4 times the pollutants per unit of fuel that the U.S, Germany, or other developed nations do? Doesn't anyone car about Mother Nature any more?