"Stewart Pinkerton" wrote in message
...
On 11 Sep 2005 22:29:13 GMT, "Gary Vander Schel"
wrote:

"Stewart Pinkerton" wrote in message
...
On 10 Sep 2005 03:36:46 GMT, wrote:

snip

Probably people who don't believe that high octane petrol improves
performance. BTW, you can't buy petrol that bad in the UK..........

Really?

Yes. Your 'regular' 87 octane fuel is the equivalent of about 92 RON
in Europe. UK 'regular' fuel is 95 RON, with 98 RON (the equivalent of
your 93) being available for high-performance engines. Note that most
European engines have their power ratings quoted for 98 RON fuel - it
*does* make a difference.

If I want to fill up my tank with 94 octane gas, who are you to tell
me
that I'm wasting my money?

I use 98. I get about 2 mpg better mileage, which just about covers
the extra cost, and more power, which is why I buy it. That you seem
unaware of this scientific fact is unsurprising.

I'm unaware and skeptical of your 'scientific facts' about high octane
petrol.
http://www.answers.com/topic/petrol
http://www.fact-sheets.com/cars/high_octane_gas/

Perhaps you should try reading some modern literature on the subject.
Most European cars have their power outputs quoted for 98RON fuel, the
equivalent of your 93, and certainly do produce less power with lower
octane fuel. Basically, the modern engine management system sets up
the engine to give best results with whatever fuel is in the tank. My
own car (Audi A3 3.2) has a compression ratio of 11.3:1, and
definitely does benefit from the best fuel I can find. Similarly,
turbocharged engines like that In my wife's TT will adjust boost
levels to suit the available fuel and atmospheric conditions.
--
Thanks for the clarification. I agree that using fuel with the octane
rating that meets (not exceeds) the manufacturer's recommendation is
appropriate. The variable timing capabilities of modern engine management
systems will allow it to run on lower octane w/ no knock (which apparently
you've done). Have you tried using fuel w/ an octane rating exceeding 98
RON?

OTOH, my wife's '97 MX-5 had a 15-20% drop in kpl/mpg when using higher
octane fuel than recommended by the manufacturer (probably due to the lower
volatility of high octane fuels).


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