do you get better gas mileage, the cleaner your gas is, or, a better grade?, what makes a gas a "better grade?

also, any more info. on the car in japan thar supposedly runs soley on water?

you get better gas mileage whatever your car was designed for

A better grade of gas means that the gas is more refined and has less impurities in it. Overall yes a better grade of gas can help you get more mileage out of your car. Because impurities can make the engine dirty and after a while your car might not run as efficiently as it can. Also a better grade of gas burns better because it has less impurities.

The three grades available at the pump refers to octane rating and basically determines how much compression and timing advancement can be tolerated before knocking occurs. Basically you need the grade that your car was designed for. Often the octane ratings is raised with additives, cyclic/aromatic hydrocarbons and ethanol being some of the additives used. Indeed the term "premium unleaded" was legislated in as a way to sell E10 (gasoline with 10% ethanol) since the previous legal term "gasohol" had developed a reputation for harming vehicles during the 70's. The sticker "May contain up to 10% ethanol" came about because the legislation allowing E85 to be sold required that ethanol content be clearly labeled at the pump hence the sticker. The stickers have nothing to do with any actual increased use of ethanol in the various grades. "Pure" gasoline in terms of a refinery product was known as white gas and had an octane rating of between 40 and 70, it's the additives that brings the blend up to what we use today. People often talk about cars "running on water" simply because it captures the imagination but water is the product of combustion and is essentially burnt fuel so cars can not actually run on water. Usually what the media is referring to are cars that run on hydrogen, and since there's no carbon involved, no CO2 is being produced, the term runs on water is inferred by the laymen who's only previous knowledge of hydrogen is the Hindenburg and high school electrolysis experiments hence the water reference. As a vehicle fuel, hydrogen is a terrible fuel and is mostly produced by steam reformation of natural gas so although the media may say that the car "runs solely on water", its basically running on natural gas. When Sandia Labs researched methods to more efficiently produce hydrogen from water (electrolysis is terribly inefficient) their conclusions was that you might as well just continue the process and synthesize hydrocarbon fuels like methanol, gasoline and diesel that could then be distributed in existing infrastructure and used in existing vehicles. The whole concept of a hydrogen economy where power from sources like solar power is stored chemically as hydrogen is pure marketing to sell more cars and promote the construction of new infrastructure because that power could easily be stored as gasoline and diesel with the same environmental benefits (the carbon would be from CO2). If you really wanted to benefit the environment, you would simply change the production of gasoline/diesel from fossil fuels to something more sustainable like biomass or directly from solar power like Sandia Labs did but the car manufacturers don't care about the environment, they just want to sell more cars and if people think they're being environmentally friendly and that sells more cars then so be it.

no, gasoline is a commodity and there are no grades. If you mean octane rating, then you need to use the octane that your engine was designed for else you can damage the engine. water will not release energy, so there can be no car run on water. If you mean the use of H2 from water, Last month, the Department of Energy (DOE) finally conceded that hydrogen won't be a part of the near-term solution to global warming, the peak oil crisis, or anything else you can think of. They're cutting back funding dramatically on hydrogen research. This is a triumph of physics over policy. In the long run, physics will always win, but we have way too many policy wonks in Washington without a clue about how the physical world works.

The quality has nothing to do with the grade, or octane rating. Instead the quality has everything to do with the quality being delivered to the gas station from the refinery and most importantly, how clean the underground storage tanks and piping are for that individual gas station.

Octane rating makes no difference. Buying a higher octane than you need is a total waste of money, it won't make any more power but it took more petroleum to manufacture. Buying a lower octane than you need will just make your engine run badly which will damage the engine and hurt your fuel economy. Most cars take the lowest octane rating. Car that runs on water, yeah, yeah... heard it all before. It doesn't exist unless you can take it to Wyotech (any automotive tech college would do) and have them pop the hood and stick it on a dyno and play with it for a few weeks.

You can get better mileage by installing the system below.

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