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Audi A6



  • I'd have to look again, but I could have sworn that the gas cap label on my A6 says "use premium fuel, 91 or higher"... or something to that effect. I believe the 91 is acceptable, but JMO...
  • ivan_99ivan_99 Posts: 1,681
    It all depends on your definition of “damage”.

    If you mean a head gasket blowing out…probably not. If you mean black smoke puffing out and the car dieseling after you shut it down…probably not.

    I talked to a relative who’s an engineer (non-Audi) and he said you’ll probably encounter problems “down the road” if you CONTINUALLY used a lower than recommended gasoline grade. So if you’re running out of gas in the Appalachian’s and you hear dueling banjo’s in the distance you can put in the 87 octane and not worry about it.

    If you want to put in 87 for the next couple months when gas is high you probably won’t run into problems; but that goes back to the false economy of the lower octane…which I know is not your direct question.

    My relative said you may have more carbon related issues with the injectors, fuel systems etc…though who knows.

    So…short answer NO the donuts will not blow your diet…unless you eat it all the time :)
  • At 4 payments I am on my third replacement advanced key switch. Grand total of four switches.

    Otherwise the car has been flawless or close enough.
  • What would be the purpose of using lower grade gasoline if, as at least two "reputable" (and no, I don't mean me) people have told me (and explained why) it will actually COST MORE to use the lower grade?

    It seems counter intuitive to use premium in a car that "can't benefit" from the higher octane (and therefore more expensive) AND it likewise seems counter intuitive to use regular in a car that is specifically designed for premium when the results in the pocket book for either behavior are the same: more money out of your pocket for no reward.

    I would imagine that a manufacturer (or at least its selling arm) would rather their cars be sold with the notice "runs optimally on Regular."

    I do not believe Audi markets its cars as requiring premium fuel to make the car more "upscale" in any way, shape, manner form or regard.

    Indeed, if Audi could accomplish "premium" performance on regular, wouldn't they just do it rather than force their customers to buy more expensive fuel?

  • I read the very easy to understand comments wherein the poster switched to Premium in his Audi and saved a gross $6.00 at a $1.80 cost for a net savings of $4.20.

    Add to this the slight damage ("damage") that using the low grade stuff causes (see above posts on the subject) coupled with the statement that seems almost incredible (something about chintzing out on the gas on a $50K car) and I say we shoot this topic since beating it to death has apparently not been successful.

    Just a thought. :shades:
  • shiposhipo Posts: 9,152
    Well said Mark. I cannot tell you how many posts I've read from folks who want to put Premium in their car built for Regular, hoping to improve their mileage, as well as the reverse of that from folks who just dumped 50 large on a new car and want to put Regular in their new ride to save money. I really don't understand why so many people attempt to second guess the very skilled engineers who design these modern engines.

    At the risk of repeating myself, "Folks, the combustion process is extremely well understood and has been for many many years. If an engine is designed to perform best on any given grade of fuel, then by deviating from said grade, you will reduce your performance both in terms of acceleration AND economy."

    Best Regards,
  • Sorry to be so late getting back to you. My owner's manual strongly suggests using 91 octane for performance, but that it is possible to use 87 octane gas [performance will be decreased, due to the engine management system retarding the spark.]

    The only octane grades we have in Houston are 87, 89, and 93. For awhile, I actually filled half of my tank with 89, and half with 93, just to get the right "average" octane. When I spoke to my service advisor about this, he said that going up to the 93 would not help. . . that as our temperatures here are so much hotter, the 93 octane gas tends to vaporize too soon [at leasst in my 2.7 T], and that I would be better off just using 89 octane, which I did for over three years. It was only in the last couple of months that I switched back to the 93 [Shell V-Power]. I don't know whether the benefits I've found would be true outside of our climate here, or with another refiner. Re: using only the 87 octane, my advisor never, ever cautioned me about using it. Given that I seem to be receiving better performance/mileage with the 93 [in spite of what he said], I don't know that I would take his word on this as "gospel."
  • Notwithstanding protestations about the subject having been beaten to death, I would simply want to reiterate what was, and remains, a simple question. Can using lower octane fuel DAMAGE the engine in a 2005 Audi 6 3.2 engine? Yes or no? Don't know?

    I am not interested in the debate of whether it's penny wise and pound foolish, or any of the other tangents that have been launched into recently. I use premium in the car and intend to continue to do so. Nonetheless, I would simply like to hear from other owners as to whether or not they have read anything definitive as how or if lower octane fuel could damage the Audi engine -- corroborating what my Audi service advisor told me. If you don't have an answer that responds to the question, feel free to skip it.
  • As if this is a good answer: I called my Audi service manager (a guy who has several "certs" on the wall, however these certificates do have the tell tale Audi rings on them), he seemed to not fully understand the answer, as his comments had to do with the virtual irrlelevance of the question since he seems convinced that the cost of using regular exceeds any price reductions that may accrue.

    It was almost as if he could not fathom anyone using regular even if it were deemed entirely benign, since doing so would cost MORE money.

    I do see his point.

    Yet the question of "damage" looms -- perhaps large -- for reasons that escape me since most stations seem to run out of the lower grade product first, then mid, then premium.

    I frankly continue to be bewildered by this subject.

    All US Audis require premium fuel for performance and optimum cost. Using less than simply causes a reduction of performance and mileage an increase in costs and the POTENTIAL for engine damage, albeit (apparently) light.
  • shiposhipo Posts: 9,152
    A quick rule of thumb, the hotter the environment, inside the combustion chamber or out, the greater the need for Premium in an engine designed for such. Given that most folks think that Premium fuel has more power per gallon and many think that Premium is more volatile, I guess it's not too surprising that many think that the higher grade the fuel the faster it will vaporize. I'm here to tell you that nothing could be further from the truth.

    Fact: There is virtually no difference in the BTU or Calorie count in a gallon of gasoline regardless of which grade of fuel you are talking about.

    Fact: The reason that Premium is called for in higher compression engines (regardless of whether it's mechanical compression as in a high compression ratio, or whether it's a high net compression ratio due to an external blower) is that Premium fuel is the most stable (non-volatile) of the grades and as such it takes LONGER for the flame front to fully develop.

    The ultimate goal for an engine is to smoothly burn the fuel all of the way through as in "Woosh". If your fuel goes "Woosh" for say 95% of the mixture and "bang" for the remaining 5% you have detonation (pinging). Detonation is where a small pocket (or pockets) of "End Gas" (the unburned remnants of the intake charge) spontaneously explodes due to too much heat/pressure in the combustion chamber. A little "bang" is basically harmless, too much "BANG" and things get bent, holed, or otherwise broken. If you have a situation where there is no "Woosh" at all, and only "BANG" instead, your engine will self destruct in a matter of seconds.

    Where was I? Oh yes! The goal of an engine is to ignite the intake charge somewhere before Top Dead Center (TDC) at just the precise moment that the fuel starts to burn in a rapidly accelerating fashion so that the moment of peak pressure coincides with the exact point where the piston/connecting rod/crank throw are positioned for maximum mechanical advantage (approximately 15 degrees after TDC). Kind of nice how that works out, the point of maximum pressure pushing against a piston that can make the most mechanical twist out of said pressure.

    If the fuel is of a grade that is lower that the optimum called for by the designers of the engine, the flame front will develop too fast due to the greater volatility of the lower grades of fuel, and the peak point of pressure will be too early (press all you want on a piston that is exactly at TDC, it ain't goin' nowheres -- that's an exaggeration, but you get the idea). Not only that but since that peak point of pressure occurs in the very confined space of an as yet very small combustion chamber, the pressures and temperatures rise so fast that detonation is likely.

    What modern engines do when their multitude of sensors detect the onset of detonation (indicating either an engine malfunction or more likely lower grade fuel) is that they retard the spark (and valve timing if applicable) so that the flame front starts late enough to realign the peak pressure point with the point of best mechanical advantage. The problem here is that due to the late start that the fuel got on its burn, the combustion temperatures and pressures are lower than what they would be with premium fuel, and as a result, performance and economy both suffer.

    archichris, you mentioned that once you started using 93 octane fuel your mileage went up. As evidenced by my many writings on this subject, that is as I would have predicted. As a matter of fact, I consider it almost criminal that someone from an Audi dealership would counsel you otherwise as blown engines (both Turbocharged and Supercharged) benefit from higher octane fuel far more than any other engine on the road.

    Best Regards,
  • ivan_99ivan_99 Posts: 1,681
    Can using lower octane fuel DAMAGE the engine in a 2005 Audi 6 3.2 engine? Yes or no? Don't know?

    Yes, if used consistently through the life of the vehicle; No if only one time.
  • anthonypanthonyp Posts: 1,860
    That is the most clear and understandible description of fuel I have read Thanks Tony
  • shiposhipo Posts: 9,152
    Any time folks, glad I could be of some service. I aims to please. ;-)

    Best Regards,
  • Kudos to Shipo. Many thanks for providing facts, not friction.
  • I really like my 2004 A6 2.7T Quattro except for the climate control. It is so bad that I could write a chapter on it. I may sell the car because of it. Where's the Max AC? Why can't I just run the fan/vent without the compressor? The shifter is in the way of the buttons. I want to turn the compressor off and run the fan high for a minute or so when I've got the AC on and I'm near my destination, so I don't get condensation and the moldy smell that goes with it. Can't do it without pushing the buttons 30 times! Tick both sides up from 72 to 86 and max the fan, that's 30 pushes on the buttons! This is a luxury car, climate control should be a mode along with manual control. There is no manual control, and you have to push left and right sides. No EZ way to get Max AC, Max Heat, or fan/vent only. This is my complaint and I am very unhappy with it. Can't leave it on auto set at 72 because the condensation/mold smell that results is unacceptable. Even worse will be having to pay big bucks to fix it (after I get 50K miles on the car) - I can't believe how terrible it is. Any one else agree with me???
  • cdnpinheadcdnpinhead Forest Lakes, AZPosts: 4,056
    This is very interesting. Thank you.

    Having rented an A3 & a couple of A4's in Germany a few years ago, I began following the Audi boards because I enjoyed them so much. However, in the real (non-traveling) world, I live in the Arizona desert. Air conditioning is a big deal here.

    I like simple things. Some would say elegant.

    This doesn't sound simple, much less the other.
  • I disagree. The beauty of such a complicated automobile such as the A6 is that you set the desired temp and leave it alone. The car does all the work for you, with its thermostat, sun sensor, etc... It baffles me to read people who toy with the blower ratios, etc...

    I set the temp when I bought my car and looked at the options as to vent blowing options. Since the initial setup (which I really didn't adjust from factory default), I have only adjusted the temp. Living in TX, I use AC ALL THE TIME, so I don't worry about turning it off or on econo (though that is easily done with one button)...

    I liken this discussion to people talking about their thermostats in their homes. Most people set the temp and leave it alone. A few toy with them constantly. If a person is of the latter group, then maybe a simple Neon would be better :)
  • Sound like your condensation pan isn't draining properly. I have a 2002 2.7T and I don't have that problem at all, ever, period. [On a side note, when I want to turn the compressor off, without letting the outside humid air in, I just hit the "recirculate" button and the "Econ" button. In Houston, it doesn't take long for the lack of humidity control afforded by the compressor to become apparent.]

    I really think that your's is a condensation/drainage issue.
  • Well there you go - I just read in the manual that the ECON switch turns off the compressor. Just what I needed!
  • Thanks for your thoughts on this. I bought this car from a dealer in Houston (NXCESS Motors on eBay). It will be a big help to know how to turn the compressor off. Thanks!
  • My 2005 A6 3.2 has now passed 6,000 miles. It is getting better all the time in every way I can imagine to share with you.

    It has two "issues":

    #1 I make a lease payment and I get a new Advanced Key "start engine" switch (I am on switch #4). The dealer's A6 "expert" (service, not sales expert) says he believes a "fix" is in the works (a new switch design that places durability as its top quality.)

    #2 Without rhyme or reason the DSP Bose settings for surround sound on both Sirius and CD will revert to "normal" repeatedly. The dealer has reported this to Audi and "guesses" there will be an MMI or Bose DSP "ptf" (program fix) upcoming -- but it will not rise to the level of "campaign."

    Otherwise: engine power and fuel mileage have both improved noticeably. The all-season tires are nearly silent, seem to wear well but frankly are uninspiring in terms of their contribution to the car's apparent handling capabilities (I say apparent since the tires do their best to obscure these capabilities.)

    Nothing has broken (other than a small chip in the front window where a stone hit the glass), everything works and works like a jeweled watch.

    Complaints? Well, how about suggestions for improvement? Sure:

    Voice Command works VERY WELL, but -- the memory is forever getting full (when you have Sirius Radio, plus AM & FM, the memory for "storing stations" seems to be about 25% of what it "ought to be.") Also with respect to voice command, it MUST BE MADE standard equipment for all A6's with MMI (which is all of them) since there are 82 "buttons and knobs and switches" that may be fiddled with by the driver. I had tire pressure monitoring on my last 2003 Audi -- never needed it (glad I had it, but never needed it), now it is standard on the A6, voice command is vital, tpm is good to have, but if you could have but one, the point is, get Voice.

    Voice Command -- at $350 -- should be included and if you buy one without voice command "what are you thinking?" Especially if you plan to use the telephone "hands and eyes free" while driving (which is, after all, the ONLY way to safely, even remotely safely use a telephone when you are the driver of a moving vehicle.)

    Voice Command should be expanded to "do more stuff" -- the climate control, the heated seats (at least the driver's), and make it more useful with the Navigation System for Pete's sake. Shamelessly imitate and rip-off the Inifiniti M and Acura RL's systems voice command capabilities in fact.

    Make the steering column power actuated -- this would NOT effect my purchase decisions (having had three cars with it and many more without), but it would be a factor during pre-purchase comparisons.

    Offer more wheel/tire combinations.

    Lower the final drive ratio by 2% to 3 % and raise the ratio of 6th gear to compensate for the mileage hit such a lowering would / could cause.

    Or: improve the torque by at least 5% in numbers and have it come to full boil several hundred RPM's lower.

    Offer more colors (exterior and interior).

    Keep full maintenance, like BMW.

    Advertise about 500% more.


    I don't know if I would have loved the M35X I nearly bought more, less or just the same -- I do know this A6 is better, by far, than my 1997 A8 ever was (even after I put the full S8 suspension treatment on it.)

    I'd give this car an "easy" 9 (on a 10 point scale) and a not too hard "9.25 - 9.5."

    BTW -- I have the Audi accessory that "builds in" the Sony bluetooth phone -- don't leave home without it.

  • I am not certain, but I think it is possible that the compressor is NEVER fully disengaged even when "econ" mode is selected.

    However, the A6 can be placed into Auto/Econ mode which effectively reduces by about 98%+ any cooling capabilities. The fan in such a mode remains in auto mode and there appears to be virtually no cooling going on. I had read somewhere, however, that the compressor has no "fully off" position, rather it has a "mostly off" position -- which is called "econ."

    The dealer service manager should know the skinny.
  • I don't mind tapping the fan buttons so much, rather how the fan blower motor "squeals" in cold weather on my A6 until the cabin warms up. Absolutely no problem in warm weather, only for the first 15 minutes or so of cold weather, but a VERY annoying 15 minutes!
  • carnaughtcarnaught 'zonaPosts: 2,341
    Does anyone know if it is either hard on the engine or harmful to start a car repeatedly with the compressor on? As you (may) know, many German cars do not have a simple "off" button for the auto climate control, forcing you to tap the fan button repeatedly until it's off. With this being the case it encourages you to keep it on all the time.
  • You're definitely correct about the complexity of the A6. I received my A6 about 2 weeks ago and haven't had time to lean even half the functions. The NAV system is a pain, b/c it actually has too many roads. For instance, when I used it last week, it had Chapel Rd, East Chapel Rd, and West Chapel Rd!

    Like you, I've been pleased with the mileage so far. I've been getting about 26 MPG with the V-8, which is quite good for a car that is yet to be broken-in. The growl from the engine and its responsiveness to throttle inputs is amazing.

    The only problem I have with the car is a long slashlike dent below the driver's side door received courtesy of my parking garage and some very minor rattling in the glovebox area.

    FYI, on my 2006, the DSP surround settings seem to be retained. Also, I have an electric steering wheel and my start key seems solid so far.
  • legendmanlegendman Posts: 362
    "I disagree. The beauty of such a complicated automobile such as the A6 is that you set the desired temp and leave it alone. The car does all the work for you, with its thermostat, sun sensor, etc... It baffles me to read people who toy with the blower ratios, etc." --- "Most people set the temp and leave it alone. A few toy with them constantly. If a person is of the latter group, then maybe a simple Neon would be better"

    The there seems to be on this board an attitude among some that if others don't think and do as they do then they must be dumb, lame or confused. I take issue and offense to this crude and inappropriate way of responding to alternate points of view. This is a public forum, to be enjoyed by all, not dominated by those who presume to sit in judgement of how others should operate their cars, or when or if a question is relevant or topical.

    It is certainly fine to say that you disagree, and to give the reasons why, but this steady harangue on blower speeds or octane rating, or setting one's home thermostat, is simply uncalled for. As for the Neon comment, that's just plain rude and disrespectful. Who do you think you are to be so judgemental, demeaning and condescending? Do you presume to speak for all Audi-dom? How you choose to operate your car in Texas is your business. The fact that you do things one way, doesn't mean we all should do it the same way, nor does it mean that YOUR way, is the "right way".

    For the record, some people have different needs and comfort levels than others. Some people need or enjoy a certain amount of airflow over their face in order to remain comfortable, notwithstanding temperature setting. Moreover, in some parts of the country, such as the southwest, where temperatures are routinely 90 degrees farenheit or higher, one may find themselves getting in a very hot and uncomfortable car. When the temp is set to LO (cold) the fan turns up to its highest -- and loudest -- setting. If one is trying to back up in reverse, or enter traffic, or take a call, or converse with a passenger, that very loud fan speed can be a distraction or problem, and often needs to be turned down, if only temporarily. Then there are those who suffer from asthma, who cannot tolerate cold air blowing on them with force. These people too are concerned with fan speed.

    In other cars, turning down the fan speed, just like turning the radio dial, is a simple affair. On some Audi's, it's more difficult, and can require two or more turns or pushes of dials or switches.
    This gentleman, and others, have every right to beef about Audi's habit of making simple things inordinately difficult. This FACT has been written up repeatedly in virtually every auto magazine in recent years. The MMI is one glaring example that has been roundly criticised in the American print media.

    In sum, there are many aspects of an Audi car that are outstanding. And there are some that ain't.
    Coming to this board to vent or suggest a fix by Audi seems a worthy use of this board. I for one, enjoy hearing about other people's ownership experiences -- unfettered and unvarnished -- thank you very much.
  • ivan_99ivan_99 Posts: 1,681
    I agree.

    The problem with climate control is that it controls temperature and volume. The end result is a system that decides how much air you want and what temperature it should be. I usually like some air blowing…but not directly in my face (as opposed to my wife that likes a hurricane in her face).

    An Infiniti I used to own (in winter) would start off on high heat and fan, but then would turn the fan down and keep the temp high. This annoyed me because I prefer more air volume with the temperature less than scalding…so I fiddled.

    Some times when you’re really cold or hot you want the car colder or warmer than normal (based on temp setting) till your “core” temperature settles. I supposed they need sensors to measure the persons body temp to decide this.
  • patpat Posts: 10,421
    not to turn different perspectives into personal confrontations. Different strokes for different folks and all ...
  • Although there certainly are SOME critical articles pertaining to MMI, the vast majority of articles where these "interfaces" are discussed generally criticize i-Drive and suggest that MMI is "more intuitive." Indeed, I have read articles that say MMI represents the way it should be done. I dunno about that, since I am still somewhat on the fence about the absolute efficacy of these systems (at their current state of development.)

    But, full disclosure, I remember Windows 2.0 and 3.0 being introduced when DOS was the OS du jour for the most popular PC programs (e.g., spreadsheets, word processing, etc.) -- and I thought it was crazy to use a mouse to click on an icon when it was easier (at the time) to simply key "WORD" at the command prompt to start up WordPerfect.

    To me, then, the current i-Drive and MMI type interfaces seem as primitive as Windows 2.0. When test driving an Acura last year, I thought the Acura approach was "the best" interface evolution I had seen -- and even that was not as elegant as I suspect we will see in a year or three.

    However, having said all this, MMI WITH VOICE COMMAND is (as I recall my earlier grading) about a B+.

    For $53,000+ for a car, I think we humans can do better.

    As far as fiddling with A/C and other controls go -- the only comment I can add is that these "universal control systems" (such as i-Drive and MMI) should NOT be fiddled with while driving until more advanced voice commands become the norm.

    As an example, Sirius shuffled their channel numbers and station assignments recently -- and I had previously set 25 stations via voice command. Imagine my chagrin when I commanded "Play Fox News" and the stand-up comedy channel played instead. I darn near wrecked as I violated my own rules by attempting to find the new home of Fox News while driving and without voice prompting to allow me to do so "hands and eyes free."

    I dunno about the Neon comment, I didn't think it was INTENDED to be crude and offensive. But perception (each individual's perception) is reality and I accept that some could be offended and some amused & bemused.

    I don't know enough about any other system -- since I have an A6. However, getting any of the current crop of LPS cars without voice command capabilities is IMHO a recipe for a potential "driver distraction" related accident.
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