Hi guys!

I used a wrong type of gas for my 1999 a4 Quattro. I didn't know I was supposed to use premium, so I just used the normal one. I have been driving with the normal gas for a couple of weeks. Now I'm worried if it would have affected the engine. Should I check anything to make sure everything is ok? Advice please. Thank You!

 

You didn't make a problem. The electronics just retarded your spark a bit to avoid a knock. You get slightly less performance with the spark retarded more, but it does not damage. The advantage of premium is that it knocks less, so the ECU can advance the spark a little more.

 

if he drives easy, im sure the ecu hasnt even noticed. my girlfriend only runs 87 in her 1.8 jetta cause shes cheap like that. her car runs fine. 91 really should be used, but 87 wont hurt anything. if OP is really worried, just fill the tank up with 91 or 93 and youll be fine

 

I would only worry about putting 87 in a 1.8T is if its chipped. If your stock it wont hurt anything, although you will notice a slight decrease in performance.

Only other instance where running 87 on a stock engine might be dangerous is if its really hot outside.

Jason