[nonightowl]

Has anyone found any real difference between the different grades of gas, other than the price? Do you get the cheapest grade or most expensive? Does your car get better gas mileage or run better with the expensive stuff?

I've had a slight reduction in gas mileage recently. There is no obvious reason for it, when I got the car checked out. I always get the regular grade of gas, not premium or anything since gas is costly enough. I might try a higher grade if anyone has had the same problem.

I'm talking about a traditional gasoline-powered car, and I do a lot of "stop and go" driving, though not a lot of driving...

[arcangel]

Stay with the vehicle recommendation unless your vehicle engine has been modified. Unless your vehicle requires premium it is a waste of money and is actually detrimental. Check your air filter and o2 sensor and...tires If your car is obdII any auto parts store will run codes for free.

[racee]

your tires would be your number one cause for lower gas mileage.
lol whenever i go up one grade i can feel a smoother ride...that's when i know it's all in my head. i personally believe there is not that noticeable difference if any at all and your car was designed for a certain grade so stick with it.

[lynn P.]

I'm by no means knowledgeable on this subject lol and I'm sure there's a few members who can answer this better than me. Look at your owners manual, to see what gas grade they recommend. Good point racee made about air in your tires - not enough air can burn more gas. For example, a high speed performance car like a Porsche, BMW or sport Mercedes might recommend a high grade gas because it enables fast take off. Some also think it runs cleaner in the engine but you'll get opposing viewpoints. Have you had a car check lately?

If your owners manual doesn't specify using a high grade gas then don't use it. I can't afford the high grade. Since you do a lot of stop and goes - I recommend coasting and not taking off fast or stopping fast. Learn to look ahead - meaning if you see a red light ahead, don't continue to push the gas, just coast - this saves gas. Taking off like a race car burns more gas and so does racing up to a red light. Here's a link that's explains different gas grades:

http://www.usatoday.com/money/autos/...emiumgas_x.htm

[Timgt5]

To further points others have made here, using premium gas in a car not specifically enginered to run on it can actually harm your engine over time.

There is really no actual difference in the quality of the different grades of gas, the rating number is just a measure of how much compression a fuel can go through before it detonates ( in a car gas and air detonate inside the combustion chamber, the series of those controlled explosions are what power your car). There are a small group of cars, mostly high performance luxury or sports cars that require higher octane fuel to get to their maxium performance. For an ordinary lower compression car however this is not needed, the cars engine mangement system will not alter the preset ignition timing when using the higher octane, this is very different from the old more reactive caburaters from the 70's and early 80s. Bottom line use what your owner's manual recomends.

Tire pressure is very important as well and should be checked on a regular basis. If all American drivers got into this habit millions of gallons could be saved a year. The manufactor's recomended pressure can be found either in the manual, or on a small sticker on the inside of the driver's door.

Also weight is important as well. Make sure you are not carrying anything around in your trunk that you do not need to have in there.

Finally you may want to have your ignition timing checked out by a reputable mechanic, a car with bad sparkplugs can see a significant decrease in fuel mileage. I also recomend periodically putting fuel injector cleaner in your gas tank every two or three thousand miles. This will keep deposts off your engine, and help the car to run better for a lifetime.

[nonightowl]

The "coasting" idea seems to have gotten my mileage up to where it usually is! Now, I coast whenever I can, like when approaching a red light, even if someone is tailgating me. They want to speed up so I can stop anyway??????? Idiots!!!! That wastes gas too.