In what ways does superunleaded petrol differ from unleaded?

Question

Are they made for different engines?

I have always used superunleaded petrol. I wonder if I can change to unleaded. Is superunleaded just for high performance cars? Can I use it for ordinary family cars?

Answer 1

the octane level is higher.
In the old days it was 3star 4 star and 5 star.
Basically its for performance engines.

Answer 2

Well, there does appear to be no small amount of divergent responses!
Super unleaded (or "premium unleaded")has a higher octane rating than regular unleaded. "Octane" is a number which rates the anti-knock ability of gasoline. For many technical reasons higher performance engines need a greater amount of anti-knock capability than more ordinary ones. "Knock" is when a part of the air/fuel mixture explodes during the combustion stroke of an engine. This is bad because it can damage internal engine parts and increase emissions. Modern computer-controlled engine management systems prevent knock by retarding timing or by retarding value events should it detect any knocking. The only consequence to this automatic adjustment is reduced engine performance. As a hidden benefit, Super unleaded usually has more added engine cleaner than regular unleaded.
OK with all that said, if an engine is designed to run on regular unleaded there is no advantage to using super unleaded. It is a money waster.

Answer 3

My sheds on fire , you are wrong , there has never been 5 star petrol in this country it was 2 star , 3 star , & 4 star , then diesel . i think you maybe thinking of the group from the 80`s " five star " a bit **** if the truth be known . .... any way ... super unleaded was brought in for high performance engine`s it burn`s a lot hotter and quicker than standard unleaded fuel and yes you can use it in your car / bike whatever as long as every so often you use super unleaded to burn off the unwanted carbon build up in your engine .

Answer 4

It's higher octane which means it has more energy. In laymans terms if you explode premium unleaded in your engine you get teh energy you would get from detonating a petrol bomb, where as high-octane would be like detonating a similar amount of cemtex (obviously not that extreme of difference but the cemtex if channeled controllably to the wheels would make you go a lot faster).

Answer 5

Reducing Gas Prices

We can reduce gas prices, and in many cases reduce our expenses in other areas, by reducing the demand for petroleum products. How do we reduce demand? Easy. Reduce consumption. Here are some suggestions on how to do that:

1. Make sure your tires are properly inflated. Improperly inflated tires reduce gas mileage. Most tires should be inflated to 32-35 psi, but look on your tires for specific numbers.

2. Make sure your engine is properly tuned. An out of tune engine wastes gas and money. Have it checked.

3. When you stop at a stop light, stay stopped until the light is green. Don’t try to ease up a little at a time – this not only wastes gas, but wears out your brakes sooner than normal.

4. Accelerate slowly. Rapid acceleration (“jack rabbit starts”) wastes gas.

5. Use synthetic oil whenever you change or have your oil changed. Since it’s synthetic, you are not using a petroleum product therefore you are reducing demand. Most cars actually get better gas mileage with synthetic oil, so it’s a win win.

6. Whenever possible, use alternative fuels such as biodiesel or E85. They not only reduce petroleum consumption, but they are cheaper and better for the environment. Unfortunately, they are not widely available yet in most places, but start asking about them when you buy gas and fuel distributors will begin to get the message; if they think there is a market, they will supply that market.

7. Don’t rush out to buy a new car… but if you are in the market for one anyway, consider buying a more fuel efficient car or even a hybrid car. Hybrid cars are more expensive but you can get a federal tax credit which will offset much of the extra expense and if you do a lot of driving, the money you save on gas will offset the rest.

8. Carpool.

Answer 6

It's higher octane, and a little different blend.

My car has a tendency to overheat when sitting in traffic, so I use premium when I'm going out of town because it doesn't overheat as easily with the higher octane.

My truck is so old, it pre-ignites alot, so I use premium in it.

If your car knocks or pings, use the higher octane premium. Otherwise, if it runs well on unleaded, don't use the expensive stuff. You're just wasting your money.

Answer 7

I was told that premium fuel is the same as regular, the different brand gas stations only add their own blend of additives to increase octane I know that although premium has more octane it is a filthy burning fuel compared to regular. I would compare the average cost per mile with both fuels and take into account the extra carbon buildup that premium causes in your engine. I have heard that once you start using premium fuel and as your compression ratio increases due to the carbon taking up more space in your combustion chamber increasing your compression ratio that you'll have to use premium exclusively... I'll stay with regular unlead myself.

Answer 8

the octaine was higher
this allowed some older cars to run on it insted of the 4 star whitch is no longer with us. if you have an old car check before putting it in most garages should still have this info.
if the car wont run it then im sorry it means a head job as the valves & vale seats will need replacing

Answer 9

the octane rating will be higher on superunleaded, so you get more bang for your buck as it were. youll accellerate slightly faster on super, and itll pick up slightly faster, but youll enjy the adrenaline buzz, and knock 7-10 mpg off your average consumption.

the only real difference between the engines is the compression ratios, teh super being slightly higher. and a tad more powerful

Answer 10

Apart from having a higher octane number it also contains stuff that cleans your engine as you drive making sure you don't lose power.