Automania/Repair & Maintenance

AUTO QUESTIONS AND ANSWERS FOR WEEK 28 YEAR 2001

by Bob Hagin

Q. I have a 2000 Buick Regal GL with a supercharged engine. On the gas cap it states that you must use premium gas only. However, when I bought vehicle last year, I was told that premium was not necessary and that the writing on the cap was in error. The same salesman informed me by phone several weeks later that premium gas was required after all. Because of the high gas prices I am real reluctant to use premium and frankly I do not see any difference between the two. My Regal does not ping at all when I use regular unleaded regardless of where I buy my gas and my performance seems very strong. Am I doing my vehicle any harm by not using premium? My Regal currently has 14,000 miles on the engine.

A. If the Buick factory states that 97-octane gasoline is the recommended fuel for your supercharged Regal, take its word for it. The higher the octane rating on gasoline the slower the "burn" rate and the more slowly its flame-front moves across your pistons - a plus for high compression engines like yours. The higher-than-normal compression pressures come from the additional fuel/air mixture that's crammed into your Buick's combustion chambers. The extra cramming pressures produce extra heat in the mixture and as the engine develops carbon build-up in the chambers, the compression goes even higher. Your engine compartment is so quiet you probably wouldn't hear pinging unless it was pronounced but the real danger is in detonation, the uncontrolled explosion of the fuel in your cylinders rather than a time-controlled burn. Detonation can blow holes in the center of pistons or blow down the "lands" that separate the rings. Your Buick is, in reality, a hot-rod and you should treat it as such with high-octane fuel and shorter oil change periods.

Q. I have a Lincoln Mark III. I can get into it easily and it rides very well. The trouble is that sometimes it won't start and just makes a "clicking" sound. I have taken it to an auto shop several times but they can't find anything wrong with it because it always starts for them.

A. Usually when a vehicle refuses to start when the key is twisted to the Start position and the action is accompanied by a clicking noise, the problem is that the battery terminals are corroded. When they're corroded between the battery terminal and the ends of the battery cable, the cure is to disconnect the cables from the battery, and clean them and the battery terminal ends. Most mechanics use water and baking soda or a prepackaged chemical preparation that will neutralize the build up. This is a simple job that should be done periodically. If this doesn't work, the next thing to check would be the solenoid that operates the starter motor itself and its connections. The last link in the chain is the starter itself which may have a "flat" spot on the armature and will have to be replaced.

Q. I saw an advertisement on the internet promoting a device that snaps around the fuel line on a gas or diesel engine that rearranges the hydrocarbon molecules in the fuel and makes it burn cleaner and increase engine power. Does this device really work?

A. The first time I came across this device was in the early '70s. Back then, it was called "cow magnets" and alluded to the small magnets that were stuffed into bovines where they would attract and hold bits of metal to keep them from tearing up the animal's stomach. At the time, no impartial lab proved it to be of value in a vehicle. I recently came across an ad like the one you saw and it said that it was tested by a subsidiary of Ford but the P.R folks at Ford had never heard of it. Randy Satterfield of the Federal Trade Commission just issued a warning on alleged fuel saving devices and gives his contact phone number as 202-326-3407.