what kind of gas do you put in your audi

[sergeA4]

hi all
just bought a 2005 a4 1.8t quattro, and the dealer and mechanic told me to put premium only.
Just wondering if thats true cause i know a lot of people who put regular gas in their vw and audi 1.8t and it hasnt been a problem. Just wanna get your opinion, thanks

[Shi-Fu JaY]

I ran 87, and 89 gas before with no problems. btw im 1.8tq too
you can run 87 gas just fine, but just dont take the car high in the rpm. drive normal.

I've been using 89 gas for couple months now. no problems for me. then again, I drive like an old lady to save more gas.

[tubbs_4mo]

i have a 2005 1.8T as well and I started out putting regular, but with the outstanding drop in gas prices as of late, I have begun only putting premium.

Okay, obviously only half of that is true, but I really did just start using premium only, and feel nothing more than a psychological difference. Although, that peace of mind is enough for me to continue.

[sergeA4]

im thinkin of putting 89 anyway, i was just worried about problems cause the audi dealer was telling me if you dont put premium gunk will build up in the engine and fuel filter, causing problems for the engine
otherwise im fine with 89

[fire27]

i always use 93 as the place i get it is 10-20cents more than regular so its worth it. if you really want to see the difference run a tank of low grade crap then run a tank of high test you will notice a huge difference (even being stock)

[AudiA4Turbo22]

Chevron with Techron 91 FTW!

[brewmastr]

i always run 92, but once jackass put 87 in my car (oregon has pump attendants, and they will not let you pump your own gas) my car ran terrible with 87, it is chipped stage 1 though but it was just unbearable to drive it was retarding the timing back too much to be enjoyable.

[mxrz]

Shell V-Power 91oct 60% of the time, Petro-Canada 94oct the rest.

[CyberPMG]

Shell V-Power 93 octane. When out playing at Mid-Ohio Sports Car Course, I'll use Sunoco 100 octane.

[dougyfresh]

When I was bone stock I would run 89, 91 or 93 depending on what gas station I was at. I tend to avoid the cheaper stations for their gas usually contains quite a bit of water.

The Audi/VW spec calls for 91 octane. You'll see this on the inside of your gas filler cap.

You can get away with 89 occasionally. 87 you're killing yourself. When you drop down in octane the car also doesn't have complete combustion. A result of this is increased knock within the engine cylinders. When knock voltages get high the ECU pulls timing advance to operate the engine safely. Reduction in timing advance equals less power. IF it is really hot out and you're running 87 octane (or some other crap fuel) the ECU could, potentially, max out on the amount of timing advance it pulls out. It can only pull a total of 12deg before top dead center (bTDC). If you're maxed out at 12deg timing pull (channel 020 in VAG-Com... aka "CF" or correction factor) then your car is pinging like a mofo and running like schit. In otherwords, you are destroying your motor.

One of the things 'chipped' cars add to the ECU programming, in addition to more turbo boost, is more timing advance....


My current file is written for 93octane and has an aggressive built-in timing advance curve. If I run anything less than 93octane I'm pushing CFs of 12. NOT GOOD.

What fuel do I use? I try to use Shell or Sunoco or BP. I have a ton of stock in Exxon but for some reason refuse to use their gas.

[Gom33]

Chevron with Techron 91 FTW!

me too...

[Tgr_Clw]

Threads like this make me laugh.

Why in the world are driving an Audi if the difference of $25 per month is relevant to you?

Your car will provide better fuel economy on 91 offsetting the cost btw.

[pondside36]

Seriously they wouldn't recommend premium if you could run something less with out adverse effect.... Premium ast stated above in Doug's explanation is the way to go...
I use Shell V-Power most of the time or another 91-93 when not available.

[akarol]

Always premium (93). I try to go to Chevron as much as possible but mostly go to a nearby Mobil. It is well worth the $3 extra dollars to use premium. It'll keep your injectors spiffy clean and due to it burning cleaner, you usually get a tid better mileage, which more than compensates the extra cost. I don't know why anyone would ever not use premium on their cars.

[b6onboost]

Always premium, 93 octane, as my mods require it. Mostly Shell V-Power since there is a station close to my house and they sell 93 at 89 prices on the weekends.

[Killerteve]

When my dad bought his porsche in the winter the guy told him to use 89 cuz it was fine and would give you a better start in the winter(someone explain that). Hearing that I filled up with 89 before my 1000 mile trip back to school and my first tank of gas barely lasted me 300 miles when I usually get like 350-380 on 91. Ever since I've been back to using 91.

[Exanimas]

Threads like this make me laugh.

Why in the world are driving an Audi if the difference of $25 per month is relevant to you?

Your car will provide better fuel economy on 91 offsetting the cost btw.

I completely agree with you on people driving cars like these shouldn't be cheap when it comes to gas (for a few measly dollars more), but then again you can get a used A4 for like $15K. There's Honda Civics that cost more than that. You can't really characterize how cheap someone is by their car.

[04QuattroTurbo]

Ever since I owned the car thanks to a post here about it, I only been using Shell V-Power 91 Octane because I am in California . Our gas suck anyway, this car is a sensitive, high maintenance, broad...you really have to treat her as such. Only the best Baluga for my baby! I have been adding an Octane booster just to keep things safe. As fore mentioned, Premium will give you better MPG, so it may offset the added cost, 20-30 cents per gallon. I try to keep my fillings cheap by not letting it get pass 1/2 a tank, I know it shouldn't make a difference, but I just like seeing smaller amounts!

[mxrz]

Seriously they wouldn't recommend premium if you could run something less with out adverse effect.... Premium ast stated above in Doug's explanation is the way to go...
I use Shell V-Power most of the time or another 91-93 when not available.

Adverse effects? Hardly. The 2002 brochure even states that 87oct can be used, and 91 is recommended for "maximum performance". The 1.8T can safely run 87 all day long...

[pondside36]

^^ Still with that being said a higher quality gas is better for your engine NA or FI... so premium would be the way to go... my 02' has the 91 octane tag on the gas cover..

[mxrz]

It is better, I won't argue that.

[04QuattroTurbo]

Before I owned this car I used to not be a great believer in premium or even branded gas. Having worked at a gas station most of my High School years and college, and seeing the same truck with only two tanks fill the underground tanks, I use to think it was all a scam. Drivers would tell me that the "additives" were added while filling up the underground tanks...uh huh...like a truck driver can get the formula correctly. Not to mention working at a BP and having Shell and Chevron and Beneto trucks (same guys who supply the bargain, second tier places) deliver gas. Again, they claim that the driver would "mix up" the branding formula as the gas enters the tanks...

With my M35, I always used 87, the manual says 87 and the cap says for maximum performance use 91. Mind you the M has over 100 more horsepower than a stock A4. So I was going to go business as usual, until I started reading these darn boards and their articles about gas. I really would hate to mess my car up simply because I decided to save $25 a month.

[dougyfresh]

/\
It is really contingent upon how the vehicle was designed. With today's computer-controlled vehicles the engines are more temperamental to grades of gasoline. They are designed right up to the edge.... trying to get the most amount of efficiency out of a very inefficient cycle (relatively speaking). As a result of the computer control logics, changing the grade of gasoline drastically affects both performance and [fuel] efficiency. The German automobiles are notorious for this. Most other manufacturers out there are catching up.

I never paid attention to gasoline octanes, let alone never used anything higher than 87 until I bought my Avant. My previous cars were 'stupid' for a lack of better words in regards to engine monitoring and air/fuel control. I never saw a difference in performance or efficiency in those vehicles when using higher grade gasolines so therefore it wasn't warrantied. Shit. I can probably put the anything (shy of diesel) in my 1972 Chevelle and it'll run perfectly fine. After all, who's counting gas mileage in a 30+ year old huge V8?

Having said that, refer back to post 10 if you want to know the affects of running a lower grade fuel in our B6 A4.

[old guy]

Doug is absolutely correct in post #10 as to to what can happen when using a lower octane. Your ECU may not be able to pull enough timing to protect the engine. However, I would like to clarify the cause a little better. The problem isn't that low octane doesn't burn completely. The problem is that lower octane burns too rapidly, even to the point of detonation rather than a controlled burn. Low octane fuels are designed to run with lower compression motors so they light off rather quickly. As the compression forces increase (especially with FI motors) you need a fuel that is harder to ignite and burn. The more resistant it is the higher you can go with the compression without causing detonation. That is the function of higher octane. The ECU is going to pull timing as soon as it "hears" a problem developing. Unfortunately it has a limited range that it can adjust for and if you push your car past that range (87 octane, full throttle, 90 degree+ weather) you could be causing damage and never know it. At full throttle and higher RPM's you can't always hear pinging or knocking. It is easy to hear at low RPM's but it is at the higher range that can quickly destroy a motor. My advice is to suck it up and use 91 or higher octane.

Cheers!

[04QuattroTurbo]

Doug is absolutely correct in post #10 as to to what can happen when using a lower octane. Your ECU may not be able to pull enough timing to protect the engine. However, I would like to clarify the cause a little better. The problem isn't that low octane doesn't burn completely. The problem is that lower octane burns too rapidly, even to the point of detonation rather than a controlled burn. Low octane fuels are designed to run with lower compression motors so they light off rather quickly. As the compression forces increase (especially with FI motors) you need a fuel that is harder to ignite and burn. The more resistant it is the higher you can go with the compression without causing detonation. The ECU is going to pull timing as soon as it "hears" a problem developing. Unfortunately it has a limited range that it can adjust for and if you push your car past that range (87 octane, full throttle, 90 degree+ weather) you could be causing damage and never know it. At full throttle and higher RPM's you can't always hear pinging or knocking. It is easy to hear at low RPM's but it is at the higher range that can quickly destroy a motor. My advice is to suck it up and use 91 or higher octane.

Cheers!

I agree, the additives in Higher Octane gas retards the flash point so that it burns slower, as you said. It is almost counter intuitive until you think about how engine dynamics and harmonics work in a 4-stroke engine. I agree bottom line, watch 1 less movie a month or cancel your Netflix membership, turn off the AC at home, use CF light bulbs, don't run the water when you brush your eat, wash your car once every two weeks instead of once a week if the $25 a month is too much to handle.

BTW, DougyFresh what is a CF as you refer to it in your post, post #10?

[old guy]

BTW, DougyFresh what is a CF as you refer to it in your post, post #10?

From Dougs post #10: (channel 020 in VAG-Com... aka "CF" or correction factor) The correction that the ECU is applying to the base timing.

[woofster]

Good explanations in this thread. There always seems to be octane questions in all automotive message boards. I guess it's one of those things!

I personally have not used anything other than premium (91 octane here in Toronto) for either of my cars. I ran a test many years ago in my 1.8T Jetta and discovered that there was a noticeable decrease in fuel economy running 87 octane. I then made the switch back to 91 octane and I've never disregarded any owner's manuals ever again!

[favianjanitra]

Chevron 94 every time

[old guy]

I ran a test many years ago in my 1.8T Jetta and discovered that there was a noticeable decrease in fuel economy running 87 octane. I then made the switch back to 91 octane and I've never disregarded any owner's manuals ever again!

That is exactly what I would expect. As the ECU pulls timing to keep the lower octane fuel from knocking your performance decreases since you are developing less power from your fuel. Your mileage decreases accordingly.

[AudiA4Turbo22]

i have proof between companies on our 2006 ML500 my dad used to fill only ARCO 91 and the car would always knock always sounded like a diesel! we then switched to Costco gas which is either shell, or mobil and well the sound lightened and the car felt stronger!

[Pr0n]

The manual says you can run a minimum of 87, but 91 (or higher) is recommended. 89 octane Winter Gas might be possible as well (my cousin does this with his M5.)

[B6Lovin]

why wouldn't you just run premium? it's only 20 cents difference per gallon.... a whopping 3 bucks.... wooooo

[A4p]

95 euro unleaded fuel, nothing under there.

[Tiesto]

why wouldn't you just run premium? it's only 20 cents difference per gallon.... a whopping 3 bucks.... wooooo

Just another shining example of people owning things they really can't afford. Putting 89 in an M5...

[Pr0n]

Just another shining example of people owning things they really can't afford. Putting 89 in an M5...

lol I highly doubt it's a monetary thing as the M5 isn't even the daily, but specifically Petro-Canada, as recommended by his friend who works as a BMW tech and did the same with his own M3 and now his 6-something.

I personally run whatever I can siphon.

[Guru_A3]

We use 95 or 98

[eg6siR]

i usually run 93 exclusively from Sunoco, and on occasion i add Asus to it and make it 107.

12 gallons of 93 + 1 oz of Asus = 12 gallons of 107

12 gallons of 93 + 1.5 oz asus = 12 gallons of 116

[Casius]

Used to run 94, there's no point really, 94 is an ethanol blend so your car burns more gas at least Sunoco is. I run Shell 91, gas milage has improved much, and you know what, there's a reason why consumer reports rates VW so low... Because people don't follow instructions and bitch when it breaks. I know it can run on 87, I understand the theory of why it can, but I still don't do it because the people that built the machine, know whats best for it. Run 91 and you won't have to worry about anything.
If you're really interested, the pinging shouldn't occur until you open you intake manifold past a certain point, ie apply high throttle, don't know where it would start, but it'll start up there. Until that point your motor is not achieving full compression ratio with respect to atmosphere.
OH and if you live at high altitude you can run 87 with no worries :P

Use 91 :)

PS unless your ECU is specifically programmed to run on anything higher than 91/94 ish, you're wasting money on 100octane fuel. You're not getting predet on 91 soooo...

[VAG_4ever]

93-

my mom has a b7 2.0t and puts 91 in hers and she had some engine noise and took it to the dealer and they said a few tanks of premium would clear the noise up..

[Papachristou]

premium duh!!! thats like asking if i use cheapo condoms or trojans