matthew wrote:

El Protoolio wrote:I say this as someone with exstensive experience rebuilding and performance tuning car and 2 stroke bike engines, and not just because I think Matthew is a dick, which I do think, but thats another thread altogether.

I don't question your understanding of engines, but I've owned three cars thusfar in my life and have always put premium in them and have never had a problem with pinging. Why even risk it....when you put 87 in you are increasing the risk of pinging quite a bit because. I also am convinced that 93 octane gas allows for better mileage as well because the higher octane content allows for higher compression, and most automotive engines these days have a pretty high compression ratio anyway and thus can handle high octane gas just fine.

Any engine can ping. It depends on what enviorment it's working in. If you think a pinging engine is an emergency, I can tell you 100% it isn't. If I put 93 in my tank here in Chicago, and then drive the Rockie Mountains-guess what, it's gonna ping. You are correct about gas mileage potentially being higher, but there are more important things to consider. And no, most engines are not high compression engines these days. They may be higher compression engines-higher than yer mom/dad's car, but not truly high compression. Yes, maybe they can handle the higher octane, but tell what yer spark plugs look like when you change them out. I'll bet the ends are white.

I will give you a dollar (US) if you stop dispensing automobile advice.

You only use premium if you have to. In most engines it's a waste.

In a modern production car engine there's a knock sensor, if the motor starts to ping/knock the ignition timing is retarded until it stops. In the real world this would translate to less performance from the enigne.

So, if you notice a difference with premium, then use it. If you switch to a tank of regular and there's no difference, then use regular.

In motorbike world there are no knock sensors - still, we are told that using high octane fuels when not required can lead to less HP and greater depsits in the combustion chamber over the long term.

Keep in mind the octane rating of a fuel determines how much pressure the fuel mixture can be put under before it self-ignites. Self ignition (from not enough octane in the fuel) is bad - pinging. However, too much octane in the fuel will lead to a "slower burn" in the chamber, some unburnt fuel being left over, less power, and deposits (from the unburnt fuel) being left in the chamber.

If the motor does not requre high octane fuel, it will make more power on lower octane fuel. This has been proven time and time again.

Hey, if you're really bent on using spendy gas, go get a drum of some VP... it'll run ya about $13/gal.

best,
t

matthew wrote:Initally I was only speaking practically in regards to taking care of one's car. I say that what with the high performance, high compression engines that are in most newer cars these days it seems a prudent choice to use higher octane gas in order to lessen the chance of pinging. Lower octane gas is simply more volatile and hence the chance of pinging is higher. So in practical terms: Why run the risk of fucking up what is for most people a sizeable investment when the cost of avoiding the risk is really not that much, and may in fact save money long-term?

Your advice is not 'practical' or 'prudent.' You don't know what you are talking about.

You could fill your toilet tank with Evian and it would still work. So what? That makes it a good idea?

mastermind wrote:Keep in mind the octane rating of a fuel determines how much pressure the fuel mixture can be put under before it self-ignites. Self ignition (from not enough octane in the fuel) is bad - pinging. However, too much octane in the fuel will lead to a "slower burn" in the chamber, some unburnt fuel being left over, less power, and deposits (from the unburnt fuel) being left in the chamber.

The man speaks the truth. That left over fuel also has the potential to cause the engine to back fire.

tmidgett wrote:

matthew wrote:Initally I was only speaking practically in regards to taking care of one's car. I say that what with the high performance, high compression engines that are in most newer cars these days it seems a prudent choice to use higher octane gas in order to lessen the chance of pinging. Lower octane gas is simply more volatile and hence the chance of pinging is higher. So in practical terms: Why run the risk of fucking up what is for most people a sizeable investment when the cost of avoiding the risk is really not that much, and may in fact save money long-term?

Your advice is not 'practical' or 'prudent.' You don't know what you are talking about.

You could fill your toilet tank with Evian and it would still work. So what? That makes it a good idea?

I'm thinking this has already been addressed in his earlier posts.