One of the mechanics at the dealer I work at keeps telling me that I'm wasting my money with premium gas on my 1.8T A4. He says that the fuel sensors in any modern car sense the lower octane and compensate for it. I'm running the car totally stock, no chip or engine mods in it. Any comments on this?

 

you can run any gas in your car you want..... on that note, your "mechanic" buddy is write to an extent

what will happen is your car will pull timing and run more poorly.... and you will consume more fuel that you will or are with the 91 or 93 oct


87 @ say 2.00 at 200 miles
93 @ say 2.20 at 250-300 miles is a hell of alot better

 

The higher the octane, the better the ability of the fuel to resist pre-ignition (fuel mix igniting before spark plug fires) due to heat build up from the pressure inside the cylinders. A turbocharger increases the volume of air into the cylinders, and this also increases the pressure. Higher pressure means higher temperature, which means there is a better likelihood that the fuel mix will detonate early.

Generally speaking, the ECU should compensate for this and it does, but your performance suffers and in the long run it does damage the engine. You definitely couldn't do something like add 87 to a Porche or Ferrari, but Audi lets you get away with it from time to time because our cars live in the real world . I'd say do it if you're in a crunch, but don't make it a habit.

 

oh no you don't! not for my baby! shell gas station's v-power 93 octane all the way! I don't give my baby anything but the best,she'll be mad at me and wouldn't talk to me for a week if i put 87 reg in her belly,much less start!

 

you will save a couple of dollars on the gas but you will also get like 40 miles less from the tank. you do the math

 

You do know that most gas stations in the same area get their fuel from the same provider. Shell's gas is no better or worse than Hess, Valero, Lukoil, etc.

That aside, I would never ever put anything lower than 93 octane in my car. I hate going to full service stations for that very reason. A couple of weeks ago my car was nearing E, so I just pulled into the closest station without thinking about whether or not it was full or self service. I got to the pump and the guy came to the window. I was thinking "oh crap, it's full service and this guy probably doesn't speak English," but I couldn't pull away at that point so I handed him my card and went through the whole routine. I specifically told him to put premium fuel in the car and he pressed the regular gas button like he didn't even care. Thank God I noticed and I began to scream "NOOOOO!!!!" like this: http://www.youtube.com/watch?v=Tim5nU3DwIE
Thank God I caught him in time; fortunately he switched over and put the good stuff in my baby. But after those first few seconds of trauma he had me worrying for a week about what he put in my car. Since the station had one hose at every pump and buttons to select the gas grade, I was unsure if the computer in the pump would make a mistake or something. Thank God it all worked out in the end and I'm never going to a full service station if I can help it.

 

lmfaoo @ NOOOOO!

 

who said anything about shell being better than hess or any other gas station? not i..i simply just mentioned the gas station,where i fill up on premium 93 octane gas. Some gas stations,add additives to the gas,that make it better than other stations.

 

Well actually, recent studies show that gas is gas. By that I mean that one gas station is just as good as another. Personally, I don't give a damn I put at least 92 in my car every time.

 

I didn't spend all that coin on my car to cheapout on 3 bucks at the pump, ya know? It's an audi, had to expect something to cost more...lol