RE:octane booster and price of gas

[dardal@xxxxxxxxxxxxxxx]

Quoting RandalPark@xxxxxxx:


> In my opinion, even at todays prices, gas is the cheapest thing that we put
> into our cars. For my peace of mind I prefer to put the best grade of gas in
> the car to start with and not mess around with additives. I may be imagining
> it, but other than the absence of spark knocking, I feel like I get smoother
> performance from premium fuel.
> 
> Paul
> 

Paul, this is not necessarily true.  If the engine is designed for a lower
octane fuel, you are getting absolutely no benefit using premioum.  When you
drive a 60's 10:1 compression engine, it makes sense to advance the timing all
you can to avoid knock while using premioum.  This maximizes performance and
the higher pressuses and temperatures help keep the combustion chambers
cleaner.  But the lower compression ratio engines do not need the premioum. 
The hgher octane is a quality relevant ONLY to engine knock.  All other
combustion characterisits (including for example laminar flame speed, or
enthalpy of combustion) remain the same.  If there is no engine knock, then
simply you get no extra benefits with higher octane.  In fact, you may get some
drawbacks.  For example, premioum gas is usually less volatile, so the cold
start may be a bit tougher.

D^2