Does using premium gas as opposed to regular 87 octane increase your fuel mileage?

Question

Maybe it is just the way I drive but I feel like my car is getting better gas mileage when I use the higher octane fuel versus the cheaper less octane fuel. I do not know if there are any sciencifitic tests on this or if there are engineers or mechanics that know a thing about this. If so, I would like to hear your thoughts on the advantages of using premium and if it improves gas mileage.

Answer 1

idk

Answer 2

High-octane fuel is not any more potent that regular gas. It's main advantage over regular fuel is that it is a little harder to ignite (this is what the octane rating measures). It is generally required in cars whose engines use high compression (these are typically found in high performance cars). Using regular gas in these cars can result in predetonation (called 'ping' or 'knock'), which can result in engine damage.

This means that using high-test will not help your mileage any, although some cars, like the Chrysler 300M, can take advantage of the higher octane to adjust the engine's ECM to make slightly more power, but this generally decreases mileage as opposed to helping it. Even if there were a mileage advantage to using premium fuel, it would be very slight and the gain would be offset by the higher purchase cost. If your car can use regular, do so.

Answer 3

No.  There is no mileage increase by using higher octane gas.  Higher octane means it takes higher compression to make the gas explode in your engine.;  Premium gas is for cars with high-compression engines.  Using regular gas in  a car with a high-compression engine will cause the gas to explode in the cylinders before the peak moment, which can cause engine knock and ping.

There is absolutely no mileage benefit.

Answer 4

Octane rating determines the rate at which the fuel will burn.  A slow burn across the entire power stroke of the combustion cylinder is much more efficient than a quick burn which dies out before the stroke is complete.  Higher octane burns slower and therefore more efficiently.  Unfortunately, with today's gas prices, the added efficiency does not offset the increased price of purchasing higher octane fuel.  You DO get better gas mileage, but it ends up costing more in the long run.  FYI: Changing your air filter more often is the cheapest, most effective way to increase your car's fuel efficiency.  Follow the link under "Source(s)" to find out more about air filters and fuel efficiency.

Answer 5

I notice a difference in my car, not only in efficiency but power.  My car is designed to run on 91 octane, when i put 87 in the tank i lose 1.5 mpg and the car feels sluggish.

Answer 6

If your car is designed for premium and you use regular then you'll get worse fuel economy with regular and have less HP.

Answer 7

NO,,,no,, nada,,,nighn,,,uh uh...not happin...NO...

Answer 8

According to Wikipedia higher octane is not worth the price.  I had a mechanic tell me once that it actually hurts an engine designed to run on 87 octane to run it on highter octane.  Here is the blurb from Wikipedia.

It is commonly believed that efficiency of a gasoline engine is related to the fuel's octane level; however, this is not true in most situations. Octane rating is only a measure of the fuel's propensity to cause an engine to "ping", this ping is due to "pre-combustion", which occurs when the fuel burns too rapidly (before the piston reaches top dead center). Higher octane fuels burn more slowly at high pressures. For the vast majority of vehicles (i.e. vehicles with "standard" compression ratios), standard octane fuel will work fine and not cause pinging. Using high octane fuel in a vehicle that does not need it is generally considered an unnecessary expense[13], although Toyota has measured slight differences in efficiency due to octane number even when knock is not an issue [14]. Most vehicles equipped with emissions systems have sensors that will automatically adjust the timing, if and when ping is detected, so low octane fuel can be used even if the engine is designed for high octane, at some reduction in efficiency. If the engine is designed for high octane then higher octane fuel will result in higher performance (with full-open throttle), but not necessarily fuel cost savings, since the high-octane is only needed with the throttle fully open. For other vehicles that have problems with ping, it may be due to a maintenance problem, such as carbon buildup inside the cylinder, using spark plugs with the improper heat range or ignition timing problems. In such cases, higher octane fuel may help, but this is an expensive fix, proper repair might make more long term sense. There is slightly less energy in a gallon of high octane fuel, than low octane[15]. Ping is detrimental to an engine; it will decrease fuel economy and will damage the engine over time.

Answer 9

I did an informal test of this once. Using premium gasoline actually did increase my mileage by 1 - 2 mpg, but considering the cost, it was a wash.

If your car is rated for 87, that's all you need.

Answer 10

no