<div class="FTQUOTE"><begin quote><i>Originally posted by: <b>Juliet</b></i>
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<br />Premium in Washington DC was $4.45 when I drove by this AM. The gas station near home in Annapolis was only $4.30 for premium.
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<br />Tara - The higher performance engines run higher compression ratios and if you put lower octane in them the knock sensors will retard the engine to keep it from detonating prematurely, but only so well. You can permanently damage the engine by using too low an octane gas, not to mention it drives like a slug. I drive a corvette and that requires premium too.</end quote>
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<br />Actually turbo engines use a lower compression ratio than naturally aspirated engines to be able to handle the boost, especially for higher boost/larger turbo applications. But the theory you are mentioning is the same: more air into a given space on the compression stroke = bigger horse power output therefore requires higher octane to help avoid detonation. The turbo engine due to the turbo is just able to cram ALOT more air into the space which creates extreme force for the piston rods and bearings and also a volnerable fuel to air mixture which is the main reason for detonation - caused by running "Lean" or too much air to amount of fuel and the higher octane helps this. Temperature of the air also is a factor as colder air is more dense, so you get the idea why a turbo engine is way more volnerable than say a high performance naturally aspirated engine. But still same consept of more air into a given space...just had to throw in my bit after messing with cars for so many years <img src="">
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<br />And by the way I filled up yesterday and it was CI$4.88 for regular @ one of the mildly expensive stations! That's like US$5.95/gal!
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