As a recent owner of my first audi (06 a6) I realize that this may be a stupid question, but does premium gas really make a difference our can I stick with good old regular that I used to pump into my honda accord?

 

Yes it makes a difference in reducing carbon deposits in your engine, not just performance wise. I only use shell 93 octane it seems to run the best as did their low octane in our other cars. In the long run you can spend on the gas now, I avg $8 more a month or the mechanic to clean your exhaust ports and I am sure it is better on your cat because you will get a more efficient burn.

 

I only use premium too. You can pay a little now or pay a lot later when you have to replace cats, fuel injectors, coils, or fuel pumps due to using a lower quality gas. Not to mention the reduction in gas milage and performance. You aren't driving a honda anymore my friend. The A6 cost a whole lot more to maintain and drive. Good Luck

 

I only use Shell 93, it is the only Audi approved gas in my area of the country.

 

You will live using 91/89 Octane and even 87 Octane! No one here in their right mind would tell you that it's a good thing to always use it, though (use the general rule of thumb: if you treat your car nice, it will treat you nice).

It REALLY doesn't make as big of difference as anyone will point out here, but to actually address the issue at hand: because most of our Audi engines are high compression they are affected by lesser octane gas more than a normal, lower compression engine would be, hence why it is highly recommended to use a higher octane fuel while driving an audi. But again, running 89/87 will not magically ruin your engine; I doubt that it would even make a difference in the long run besides degrading performance (which normal people don't care about). As with all cars that aren't stupid (no smart ECU, etc.), they can adjust for different octanes using their knock sensors - that's sort of the point of putting them in.

 

Modern cars have knock sensors which automatically change timing to address octane rating. Given that using lower gas results in lower performance, wth is the reason that you are driving a so call premier performance sedan?

Also 20 cents difference between the supreme and regular, you end up paying $3 more on a 15 gallon fill up. I rather have one less cup of coffee a week than put lower octane stuff in a car that requires a high octane gas. Just a peace of mind...

 

Sure all modern engines have knock sensors, when the knock sensors detect knocking, it pulls back timing. Once the knocking is gone, in a high compression engine like the A6, it will slowly advance the timing until it knocks again. This cycle repeats itself over and over again if you are using low octane gas. All that slight knocking may or may not cause damage over time. It is a risk I am not willing to take for 25 cents a gallon.

 

Thanks for the responses and advise! This is the first "high performance luxury" vehicle I have owned so I wasn't sure if premium gas really made a difference (it sure didn't in my beater Honda). At the end of the day it sounds like I shouldn't risk using lower octane for the incremental short term savings.

Plus, higher octane gas will probably provide more power to operate the fantastic Denison 500 system that I am thinking about installing (kidding -- please don't report me). --Cab.

 

This debate has been done before... The FACT of the matter is there is no significant "risk". Deposits, etc. come from bad gas. period. Nothing to do with octane. I just want to reiterate this, as was posted previously. Higher octane gas is required to allow compression to build in the cylinder without igniting the fuel prematurely so that when the spark flies you get more explosion which equals power. Simple as that. Newer cars have computers and sensors. If you are running lower octane gas, the computer will adjust valve timing, etc. to compensate for the gas combusting sooner than expected. If all the systems are working correctly (remember I said significant risk) you will notice no difference under normal driving conditions. If you drive the car hard you will notice the difference.
When I drive around the city, I drive hard. I run 93. If I am doing a long casual road trip I will run 87/89, since I am not looking for power.

"Knocking" is valves being forced open/closed when they are not supposed to be and will cause serious damage if it goes on. This won't happen if all your sensors and computers are functioning.

 

Ask the guy who just put a hole in his piston is cheap gas was worth it..

That is so wrong, I dont even know where to begin....