Q: It's a 1998 Audi A6 Quattro 2.8L___87/91 Unleaded Premium I've been running it on Regular unleaded for some time now with no problems, Would it be better to put 89 in it because I sure don't want to be putting 93 in it. I bought it at 54,000 and have been driving it on Regular Unleaded up to 75,200 miles, no problem....
A: Difference It makes performance difference because of not the octane but the smoothness or richness of the gas it is very little difference but you should use 93. Consequences If you put a 89 gas it WILL have a LOWER resale value and if it is not going to be resold your engine is going to have problems in about 2 years. 87,89,91,93 Gas The higher the number the more smoothness of the gas but the octane is all the same as you can see on therefiller button or the cashier can tell you more about it Turbo or Supercharger Less torque or power will equal to lower needs of smoothness in gas but a europian car are more plastic made or high quality gel so need more smoother gas. Catalyes Converters They have a certain grade and if u use 89 on a car with a perineum catholic converter it will damage the converter and pollution will have more and it will might not pass smog test. Sensors the sensor prevents any problems the will break or be damaged. Price Sensor is 200 dollors it is 02 sensors and the joint is 20 dollars.....catalyte is 600 dollars. Me tinoisonit@yahoo.com