Hmmm...premium or super or regular...

[greall]

Without sounding too technical for the little girl when she asked me,what's the difference...

Can a old car from model year 1993 which uses 'super' start to use 'premium'?

This apparently is some of the stuff that they're learning in Environmental Science...

Greg

[Randall]

The difference is octane.

Super has less octane than Premium.

Some cars with high compression & turbo engines require higher octane gasoline in order to operate safely.

If lower octane gas is used in these engines, they could ping/detonate causing permanent cylinder/head damage.

Yes older cars can use Premium and may benefit in horsepower due to the increase in octane.

[Poser]

The difference is octane.

Super has less octane than Premium.

Some cars with high compression & turbo engines require higher octane gasoline in order to operate safely.

If lower octane gas is used in these engines, they could ping/detonate causing permanent cylinder/head damage.

Yes older cars can use Premium and may benefit in horsepower due to the increase in octane.

well said Randall ..

life is the same .. think about it

[Randall]

well said Randall ..

life is the same .. think about it

[Poser]

Yes older cars can use Premium and may benefit in horsepower due to the increase in octane.

this part is so true

[Mailman]

The difference is octane. Check

Super has less octane than Premium. Check

Some cars with high compression & turbo engines require higher octane gasoline in order to operate safely. Check

If lower octane gas is used in these engines, they could ping/detonate causing permanent cylinder/head damage. Check

Yes older cars can use Premium and may benefit in horsepower due to the increase in octane. Not quite.

Higher octane gasoline can be compressed more before self-detonating. Hence, its use in high compression performance engines. Self-detonation is what causes pinging/knocking.

Using premium gas in an older car that does not require premium would be a waste of money.

Using premium does not produce more horsepower. Increasing compression ratio increases horsepower. Essentially, use the octane that is recommended for your car's engine.

[shield_2006]

I have a 3litre fuel injected engine and I use premium and yet the car pings--does anybody have any idea--could it be heat--maybe the radiator is too small or something?

[greall]

I have a 3litre fuel injected engine and I use premium and yet the car pings--does anybody have any idea--could it be heat--maybe the radiator is too small or something?

Spark plugs check?

Greg

[lexbarker]

Mail man is right to select the gas that is recommended by the manafacture as the car is tuned to fire at the most efficient point. The octane (or octane equivalent additive) controls the burning at a slower rate so in a high compression engine you would not get the pinging as when regular gas (faster burning) is used. The pinging is an early pre-ignition wanting to push the piston down when it has not reached top-dead-centre. With the high octane the combustion is slower so you don't have the early pushing down effect and full burn almost at the top dead centre. In older low compression cars with distributors you can adjust the timing (advance) to use high octane but if it is computerise forget it unless you know how to modify the software.

[lexbarker]

I have a 3litre fuel injected engine and I use premium and yet the car pings--does anybody have any idea--could it be heat--maybe the radiator is too small or something?

Pinging is pre-ignition which may be a result by carbon buildup. When you have excessive carbon in the engine which is caused by too many short runs and the engine is not hot to burn it out. It accumulates after a time and begins to form hot spots which would ignite the gas before time causing the ping. The spark plug should be doing the igniting and not the carbon.

There may be a quick cure for that. Get a tin of carburetor cleaner (I don't know if they still sell that), The last one I used was from Ford more than 15 years ago. Remove the air intake big hose and start the engine. Spray the whole tin down the intake manifold keeping the engine RPM a little high as it may stall. And just as it is finsihed switch off the engine and let it stand for 2-3 hours. Then restart it and you will see how buch black stuff comes out of the exhaust. Your car should be healthy again.

[shield_2006]

I have a 3litre fuel injected engine and I use premium and yet the car pings--does anybody have any idea--could it be heat--maybe the radiator is too small or something?

Spark plugs check?

Greg

Yeah Greg--it was the bloody plugs--they was dead as a nit--Iridium Long Life at US$40 a pop---it is a direct injection engine and the plug has three electrodes to ensure a proper spark.