cwcironman

I have a 1998 A6 2.8 Q and my question is the effects one may experience using 89 octane instead of the recommended 91 premium. I have read so many reports about premium being unnecessary. The car has been running beautifully performance wise but recently one of my catalytic converters had to be replaced at 58k miles. Could the fuel be the reason for the faulty catalytic converter?

Jim

The only way the fuel itself can ruin a catalytic converter is if you run leaded, which is unlikely to have happened to you. You CAN run 89, or even less, the ECU will reduce the available performance as it deems necessary. No idea if you'd notice it. Otherwise, many premium fuels supposedly have extra detergents and other ingredients that supposedly help to keep the engine interior cleaner.
The real question is, what's the point of running 89 octane vs 91? So you save 10 cents a gallon. Big deal, you spent around $40k on a car. If you were to drive 20,000 miles a year and average 20mpg, you'd save a total of $100 over the course of that year. If you drive less or get better mileage, you save even less. Just stick with what's recommended and you won't lose any sleep.
Just my $0.02
Jim

cwcironman

Do you know of any good private shops that work on audi's that does not charge and arm and a leg? I live in the Pleasanton area and I am not happy with the service at the local dealer.

MoBrazen

Don't really know of any independent shops in the Tri-Valley who work on Audi, but see if any of these places are within your acceptable reach...<ul><li><a href="http://www.norcalaudiclub.org/misc/audishops.html">NorCal Audi Club Repair shops</a></li></ul>

P. Bauer

Bay Muffler in Mountain View. They are awesome!