Q: I have a 1998 Audi A6 Quattro 2.8L The Gas cap says unleaded fuel only Premium 91/87 I've been driving the car on regular for about 26,000 miles already and haven't had any problems with the car, besides it's only a 200hp car and is fast enough when I drive it No Knocking and it has 75,200 Miles I live in Chicago so the last thing I'm going to do is Pay 4.35 for Premium It's a rip-off
A: I would check the owner's manual (if you have it), or online. If it says you can use the 87 octane (regular unleaded), then don't worry about the higher grade stuff.