swsherif

Any of you guy know what are the symptoms for using the wrong gas grad , I accidentally put 87 instead of 91 and I feel that the car is not running smooth and the acceleration is not what should be . Do I need to do any thing to fix that, any help will be appreciated

Black_RS4

go to sunoco and fill up with 94, or go to Canadian Tire and buy some octane booster and dump it in your tank.

your car will have symptoms of 87 versus 91, as the ecu adjusts the ignition based on the signals it gets from the oxygen sensors.

A6Cerys

The best thing you can do is dilute it with what you should have in there. That's all I did because I really couldn't afford to syphon off and dump out the wrong stuff I put in. Keep it topped up, and that will minimise your problems.

swsherif

Thanks guys , how long it will take for the car to go back to the original performance , it's a new car,

986Jim

I run 87 in my car solid. I never run 91 ever and it's just as fast and smooth as when I do.

If you run 87 which the car is designed for, check your manual, vs. 91 you will be saving money on gas to start plus the HP difference will be negligible. If you chip the car then you must run 91 as the boost is higher and will detonate with 87. Otherwise save your money and run 87.

swsherif

according to information's I have from Audi dealer they said that the 87 will leave carbon on the cylinder head , they recomend to add some thing to remove the carbon i forgot the name of the product

1move

iTrader: (1)

READ THE MANUAL!! It strictly says 91 Octane! Unless you have an older audi! Even when you pop the gas cap open there is a sticker stating 91 octane! If you are too cheap to put in the proper gas than dont get an audi, a whole bunch of stuff can go wrong with your car if you run it on a regular basis in the long term. When you burn lower-octane fuel, the antiknock sensors will retard the spark, possibly increasing your fuel consumption. In an engine expressly designed for 87 octane gasoline, high-octane fuel is a waste. However, in an engine optimized for higher-octane fuel, such as most Audi engines, premium fuel is often cost-effective. Why dont you just stop using synthetic oil and just switch to regular while at it! Using lower octane gas results in lower fuel economy! So do us all a favor and sell your car, if you arent going to treat it properly! Especially if you have a turbo in your audi it was way far more harmful down the road, and then you are going to come back on here in a year or two and say audi's suck! My suggestion is take the car out and drive it for a while in the city not on highway because city wastes more gas! And then when you have wasted enough gas dilute it with the 91 or higer octane and also go to a local car store and buy octane booster and add it to the fuel that you have in right now!

dsq

i wouldn't worry too much if you only do it once, just don't drive hard until you your tank is replaced with 91.

986Jim

Lol.. Well thanks for that super piece of advice, I really appreciate it. I would just like to correct a few pieces of mis-information since the internet is full of it, and guys like who spouting off at the mouth who don't know what they are talking about.

First off, the grade of gasoline is set so that the car can produce a particular amount of HP. Anybody who has seriously upgraded a car knows all about this. My talon has 424whp and goes 11.8@119mph in the 1/4 mile on pump gas. I built the motor and installed it myself, Marco at Magnus did the trans. In your Audi 91 is so that car can run a particular amount of ignition advance. If you run a lower grade your knock sensor will detect knock and retard timing. By retarding timing 5-8 degrees from using 87 octane gas, you will lose say 5hp. They manufacturers dont want to claim a lower HP rating on the car for competitive reasons so they recommend a particular gas.

If you never go WOT on your car then you could run 60 octane if they made such a thing because the car in closed loop is running near 40 deg of advance anyway even with really low octane. When you floor it, timing is dropped to around zero degrees then bulids back up to around 20deg upto redline. As you reach redline if any type of knock is induced it will just not advance timing so far. So you don't reach maximum horsepower as a result.

If you don't care about max HP as I don't, (since I have a Boxster for fun and my Talon for racing) and this is just my daily driver / winter beater then you can run 87 octane in is just fine with no problems. I never go WOT on my car and just enjoy it for comfort and luxury then there is absolutly no need for 91 octance.

If you want to go fast buy another platform other than an audi to go fast in and put 91 or 94 into that. Even a GTI 1.8T would be more beneficial because the chassis is so much lighter. WHo cares about an extra 5hp in a 3500lbs car really?

On a side note, running lower octane during closed loop driving WILL NOT give you lower gas mileage. I have no idea where you got that, that is just the stupidest thing I have ever heard. Do you know what octane represents? Obviously not with that comment. It is the fuels ability to resist knock and pre-ignite. During partial throttle there is so little cylinder pressure (no boost) the stock ecu will run so much timing advance that there is so little chance of pre-ignition period. You will get the same gas mileage with 87 as you will with 91.

986Jim

Just for fun here is an older video clip from youtube I posted up of my Talon vs. my Dads Maxima on a 200hp shot of nitrous. I did custom ECU programming on both cars. My car had a built engine and my dad's car has a VQ35 totally stock with some cams and a torque converter (its automatic yes) we installed with the nitrous. Otherwise stock. Enjoy.

Just for fun here is an older video clip from youtube I posted up of my Talon vs. my Dads Maxima on a 200hp shot of nitrous. I did custom ECU programming on both cars. My car had a built engine and my dad's car has a VQ35 totally stock with some cams and a torque converter (its automatic yes) we installed with the nitrous. Otherwise stock. Enjoy.

YouTube - DSM 12.1 vs. Maxima 12.2

If that doesn't work which it doesn't for me for some reason click here YouTube - DSMJim's Channel
then click on DSM 12.1 vs Maxima 12.2 at the bottom. You can also check out my Mighty VR6 gone but not forgotten video. Thats my old VR6 GTI with a 150hp direct port shot on it. That eventually did 12.4 @ 109mph as the best on the nitrous. I did that video a long time ago so there are no real fast runs on there really...