Audi A4 Forum : “What type of gas?”

It will work but it might cause damage to your engine. The engine has a low compression ratio because of the turbo and 87 octane will not burn as well. I have an '01 S4.

I HIGHLY SUGGEST 91 octane or higher. (look at the inside of your fuel door). Even the tiny smart takes premium.  
Not using premium can cause turbo damage which is very expensive.

Premium is necessary. Plain and simple. It's not a suggestion nor is it some kind of "maybe." You risk seriously damaging several engine internals by using just one tank of plus or regular gasoline.

Plus, what've you got to worry about? You just got an A4 and the premium gas gets you better mileage than the others.

Whenever you have a turbocharger its a good idea to use premium gas.  Especially if you bought it used and the previous owner used premium, its not a good idea to witch to regular.

chevron premium. worth the price

Definitly premium.....why fork out for a great car and bugger the engine with crap fuel.

MY OPINION... ALWAYS THE BEST ... but maybe for that year i assume that they will told you , premium.. so i guess by now could be de middle one.. but even that i will go witth premium

Premium for sure. I have a 98. The engine will knock if you use less octane... It won't get you hardly any better mileage but you still need it.

Use what ever it says on your book or gas cap. Your car is programed to burn a certain octane. If its meant to burn 87 then put 87. Since it is a turbo vehicle you will probably be using 91-93 octane for the slower burning fuel which reduces your chance of knocking.

A4's are made to run on premiums only, any other type of fuel hinders their performance.

definately go with the higher octane. the higher octane fuel burns much better than the others.  the higher octane will keep your engine much happier and increase performance of your ride even though its more, ALOT more expensive

Premium only, any thing else will cause damage to both the engine and turbo.

Hi-test, 93 octane is all I used when I owned mine.  Used 89 once and i noticed a lag, idk if you will with 91, but the 93 for me worked great, and do not use fuel additives, they are a waste and actually corrode your gas tank

Premium is the only way to go. Without the high octane rating, you risk knocking and damaging your sparkplugs, especially since it's the turbo'd version.

I recently purchased an '03 Audi A4.  The dealer (not Audi dealer) never told us to use Premium gas! I filled the tank with regular and now the car is running crappy...knocking and the engine light flashing!  I was advised to put an Octane booster in which I did.  Still have 3/4 tank to use up.  Still knocking...any suggestions?  

by knocking do you mean "pinging".  i assume you do.  just go beat on it for a bit and run all of that regular out and then full up with 93 asap.  all you can do is just run the gas out.  the engine wont see any damage from this one time fill up.  also, if the car runs fine on 91 then run 91.  the lower octane a car is able to run correctly on will provide the best performance.  the lower octane fuel provides more hp (even though you will never feel it) and better fuel efficiency.  its a common misconception among people that by running a higher octane fuel it increases performance.  i was once in that boat but after studying motorcycle engines and doing my research on hp competitions, i discovered they always use the lowest octane possible because it provides more power.  use 91 in that car.  just fill up with a 93 initially to try and balance it back out.  

Thank you for the reply....... I do not think it is "pinging" I don't hear any loud noises...just running really rough and engine light flashing.  It was running wonderful until after I filled the tank with reg gas the next day it started running bad and trying to get passed 45mph is very shaky.  Also idling at a light the car vibrates terribly!  I don't know anything about cars so I am concerned putting the regular gas may have damaged something.... Hopefully running the gas out and filling with 93 octane will help significantly.  Is driving it until then  hurting the engine?  I did put one bottle of octane booster in the tank....Thank you for your help!

ML

Welcome to the world of Audi's...

one tank of lower octane fuel will not damage your car dont worry.  i did it once on accident in my 300C.  didnt realize the hemi needed 89 octane and i put in 87.  went back to 89 and its ran perfect ever since.  if you are really concerned go to o'reilys car center or autozone.  they have free diagnostic checks.  this will tell you what the problem is specifically.  you potentially have jsut had dumb luck and had something else go out along with your car at the same time you put in that gas.  also, it sounds as if you have potentially fouled your plugs.  if thats the case sometimes taking the car for a really fast ride will clean them off.  maybe try running it at high rpms (redline) for a couple minutes.  that might help clean out any carbon build up.  did it once on my crotch rocket after i fouled the plugs up and the bike went back to normal

redline your car for a FEW MINUTES!??! do that if you want to buy a new engine, that would be a great way to blow it up. crotch rockets are
completely different.

Don't run the tank out, drain it put the right stuff in.

I believe the 1.8l runs a static compression of 9.3:1 and is boosted to ~7psi so roughly it behaves like a ~13:1 compression engine....  At that compression predetonation will happen regardless of retarding timing so damage will begin to occur, it's not like the 300c where it can sacrifice it's efficiency to prevent damage. (SRT8 only runs 10.3:1 to put things in perspective)

Now drain it before you damage the valve seats.

Sorry was meant for the guy who said ' Hopefully running the gas out and filling with 93 octane will help significantly'...

I'm a woman, not a guy, and now I am REALLY confuzed!!!  Too many conflicting answers!
I guess I will see about emptying the tank somehow... thanks for all the reply's though!

lol yeah taking your car to redline for a few minutes isnt going to blow it up.  taking over redline for a few minutes will.  theres a difference.  

running one tank wont damage the engine.  and i figured trying to drain the tank wasnt really in this person capabilites.  hence the reason i suggested just running it out

Good lord there is some serious misinformation in this thread.
1) Don't use less than 91 octane -- there is no savings. You will get worse MPG and worse performance, nullifying any $/gal savings at the pump.
2) One tank of lower octane should not hurt the engine unless you drive aggressively. Run it out, don't use regular/plus again. Motronic uses the engine's knock sensors to retard timing, but it can only do so up to a certain point -- about 15 degrees.  Stay out of boost if you can, drive it at part-throttle and shift early. Keep the load low and you'll have enough overhead that you won't blow anything up.

To the user whose car is already running poorly -- you have a bad coilpack and one of the cylinders is misfiring. That's why the check engine light is flashing. This is unfortunately incredibly common. Stop driving the car. Get a diagnostic tool and scan your car so you can figure out which one it is.  Go get a new coilpack from the dealer or an independent parts place and swap it in. You don't need any tools, it takes 2 minutes. Old one pops off, new one pops on. Part's $30. If you need more help, go over to forums.quattroworld.com/a4 and ask. Worse-case scenario, have it towed to the dealer.

Why would you not put premium in it? the difference per fill up is at most 10 cents a gallon.  With a 15 gallon tank your saving a whoping $1.50 a fill up.  I only use premium.