What does a higher grade of gas do?

Answer 1

it can be use in higher compression motors, if you have a high compression engine you should use higher grade, if not it is useless

Answer 2

Lots of nonsense answers anytime someone asks about octane.

A higher grade of fuel has a higher octane rating. The octane rating is a measurement of how willingly the fuel ignites. The higher the octane, the harder it is for the fuel to ignite. In engines, this means that you can run higher compression (the fuel/air mixture can be squeezed more by the piston without it spontaneously igniting - remember, because the higher octane fuel is less willing to burn), and/or the timing can be advanced. Both of these will allow the motor to make more power.

Here is what octane does not do:

- It does not burn 'hotter'. Gasoline is gasoline is gasoline, and all octane does is affect the point at which it ignites.

- It does not burn faster.

- It does not make more power, unless you take advantage of the higher octane fuel to advance timing or make some other change. Otherwise it will make the same power as the lower-octane fuel. Some cars can actually automatically advance timing if the car is using high-test, but the gain in power would be very small and hard to notice.

- It does not improve milage, at least not by an amount that can be detected in anything other than a laboratory, and the higher cost of high-test would completely negate any fuel mileage gain.

Some cars require premium fuel (usually 91 or 93 octane). These are usually high-performance vehicles with higher than average compression ratios. Running regular fuel could cause damage to the motor. Conversely, if your car requires regular and you run premium, you will cause no damage whatsoever, other than to your wallet.

Answer 3

out of all these answers noone has ever seen the inside of a motor using both grades of fuel and harry i dont know where you got your information but it is wrong also a higher octane fuel will burn hotter and increase the power of the car it burns cleaner which will make the engine run better and last longer it is not just for high compression engines some say only use it if the motor is pinging why do you think the motor is pinging with that fuel then stops with the higher octane it is pinging because the fuel is not burning fast or hot enough it stops with the high octane because it burns hotter and faster keeping the motor clean from carbon build up it is worth the extra money if you like to keep your car running and performing well and cut down on your repair costs

Answer 4

It permits the engine to have a higher cylinder pressure without pre-ignition.

All right, so that explanation may be clear as mud. But the thing to remember is that premium gasoline itself does not create more power. Rather, it allows the engine's designer to make changes that create more power, such as higher compression ratios or turbocharging. Many engines nowadays that are designed for premium gas can detect if you have filled them with low octane and make adjustments so they can burn that fuel, but this comes at a cost of reduced power.

But if the engine doesn't originally have any features that would create enough cylinder pressure for it to ping on regular gasoline, premium gas does absolutely nothing.

Answer 5

most cars will run just fine on lower grade gas. but long term it will cause carbon build up on valves. you can use lower grade gas and get the carbon clean every year or just used higher grade gas! there are more problem (mostly durability) that might come up but its all long term. short term it make no different unless you hear ping. so if you like to keep your car for a long time use the higher grade gas.

Answer 6

If by grade you mean "octane number" then you need to use a higher number if and only if your engine is pinging (will sound like a metallic 'ping' or a knocking sound).

If you are not hearing this noise when accelerating or going uphill then you DO NOT need a higher grade of gasoline and the extra money you are spending for it is simply wasted.

Technical stuff: octane number refers to the tendency of your gasoline/air mixture to predetonate in the cylinders due to compression. Internal combustion gasoline engines are designed to ignite your gasoline with a spark. A too-low octane number combined with high compression will allow the gasoline/air mixture to predetonate, wasting most of the power and perhaps damaging your engine. Higher octane number ONLY means less tendency to predetonate. It certainly does not mean "more power" or "cleaner burning".

Answer 7

The general opinion is they don't make much of a difference, in fact, they actually are not even good for some engines. your best bet is to ask an auto parts dealer about gas additives instead.These can help alot especially with gas milage and other benefits for your engine.

Answer 8

Cost more. Using a higher grade than your engine needs does nothing. A lower grade than your car needs on the other hand is trouble.

Answer 9

If you run a turbo or supercharger its recomened. Plus if you run High compression ratio its recomened. Makes the detenation more complete and stops pinging. If you just have a plan jane car it wont make a differance. Well you might notice a quicker responce in the throttle on some cars but thats it.

Answer 10

When he car dealers show you MPG when they sell it to you, they are using perimium gas. Regular/Unleaded gets one to tree miles less per gallon depending on your engine. If your car starts to run funky, try using a higher grade of gas.

Answer 11

My source indicates that grade of gasoline does not improve performance, however, in every Nissan vehicle I have owned, the engine runs smoother with mid-grade fuel. In other cars I have not noticed a difference.