Date: Wed, 04 Apr 2007 10:50:06 -0400 From: Fred W <malt_houndnospamo.com> Subject: Re: Octane ratings.....what's the truth?
gerry wrote: > I know this is old stuff, but I would like some input (hopefully informed) > on current thinking, now that gas prices have skyrocketed and there is a > real financial significance that just didn't exist "in the olden days". > Here in British Columbia, Canada we are paying $1.17/litre in $Cdn or 1.17 x > 3.785 (l. / U.S. gal) x .86/1=$3.80 U.S. / U.S. gallon.....and that's for > regular. Let's look at about $4.10+ U.S. / U.S. gallon. Sounds like about the same prices they are paying in California. > The book for my car 2001 V70xc recommends a minimum octane (RON) of 91, and > I see regulars at 87 and mid-range at 89. If your owners manual says 91 RON, you should be OK with regular. Pump octane is RON+MON/2. RON is the higher of the two numbers in the numerator and is sometimes used in other countries as the pump octane displayed, hence it being quoted in your Volvo manual. > I listen to Radio Station KGO (San > Francisco) at night and often hear their science Guru Bill Wattenberg (PhD > etc. etc. knows all, et al) who says, "If it will run on regular, use > regular. A modern sophisticated car engine may not run initially that well, > but sensors will "re-tune" to the lower octane and will be fine.....no > damage.....no power loss.....no effect on warranty. The theory, as I > understand it is that "higher octane" doesn't mean more "power" in the gas, > it means elements added to adjust combustion rate. In his opinion higher > octanes are "generally speaking" a scam on automobile users perpetrated by > the oil companies and encouraged by the auto manufacturers. You can figure this out for your own situation yourself. Run a few tanks of regular, then a few tanks of midgrade over the same conditions. Keep track of your mileage and fuel costs (forget the # of gallons, it doesn't matter). Assuming the engine does not knock or ping, make the calculation for miles/$ instead of miles/gal. If you do better with the midgrade repeat the experiment with premium vs. midgrade. > > What's the consensus? > Who cares what the consensus is? Do you only vote for the projected winner in an election? Can't you form your own informed opinion? -- -Fred W