final more on gasoline use

[David Farber <dave () farber net>]

Begin forwarded message:

From: Suzanne Johnson <sjohnson () pobox com>
Date: August 10, 2005 5:24:23 PM EDT
To: dave () farber net
Subject: more on gasoline use



....more on use of low-octane gas instead of high...

from the car-talk folks:
http://www.cartalk.com/content/columns/Archive/1995/May/17.html




from WSJ:

Low-Octane Liability?

By JONATHAN WELSH
Staff Reporter of THE WALL STREET JOURNAL
January 4, 2005; Page D6

Editor's Note: The first installment of a weekly column answering  
readers' questions about automobiles. Questions can be e-mailed to  
mecar () wsj com.

Gasoline prices have been high – over $2 a gallon in some parts of  
the U.S. – for over a year but most drivers still haven't been moved  
to trade in their big, fuel-thirsty vehicles for more economical  
models. But that doesn't mean the cost of filling up hasn't gotten  
consumers' attention. A number of readers say they've been saving  
money by using regular unleaded gas instead of the higher-octane fuel  
specified in their owners' manuals. With the highest-octane premium  
fuel often costing about 30 cents more per gallon than regular, the  
savings can be significant. But motorists wonder whether there's any  
danger in using lower than the recommended octane.

Martin Arnold of Trumbull, Conn., says his BMW 330i "runs great on  
regular grade, no knocks no pings. But am I doing permanent damage to  
the engine or shortening its life?"

The short answer is no. Even manufacturers like BMW and Volvo say low- 
octane gasoline won't cause the harmful "knocking" that threatened  
engines 20 or 30 years ago. Knocking occurs when fuel is burned or  
"detonated" prematurely in the engine. On modern cars, electronic  
engine controls include devices called knock sensors that constantly  
adjust the vehicle's ignition to prevent knocking, regardless of the  
fuel grade.

There is a downside, though. When car companies publish performance  
data like acceleration and miles-per gallon, the figures are based on  
how the car performs using the recommended fuel grade. Cars that are  
designed to run on premium or "high test" may not perform as well on  
lower octane. The difference probably won't be noticeable in everyday  
driving, but a BMW spokesman recommends that drivers do a little  
math: Compare the car's fuel economy with different fuel grades to  
determine the cost per mile for each octane level. We've tried this a  
few times, though not with any BMWs so far, and have found that using  
regular fuel costs less per mile.
.....clip.......................

-------------------------------------
You are subscribed as lists-ip () insecure org
To manage your subscription, go to
 http://v2.listbox.com/member/?listname=ip

Archives at: http://www.interesting-people.org/archives/interesting-people/