Hello I was wondering if i need to fill my 98 audi a4 2.8 quattro with the high octane/ premium fuel. I know if you have the 1.8t or 2.0t etc you have to but is that because of the turbo? So do I need the high octane gas?

 

what does audi recommend for your car? info should be in the manual or on the gas door itself. you should follow what the mfg tells you. i do believe it is 93 octane for your car, but i also believe in santa too

 

It's built to burn premium most efficiently for power and mpg, but you can run 87 at the cost of a little performance and mpg. Your knock sensors should prevent damage from pinging, but they arent perfect. If you're trying to save a buck by running lower octane, it's a pretty small difference. Running premium for the long run makes a cleaner burning and efficient engine in the long run-if the manufacturer recommends premium.

 

i dont know about your gas lid but mine says min. 91 octane. yes i could run run 89 or even 87 but it ISNT worth the small amount of savings at the pump. sure, you wanna add it up over the life of your car, it might be 1000$ in a 100,000 miles (didnt actually do the math, just guessing) but thats only $100 a year which is less than 10$ a month. i would spend 1000$ over 100,000 miles to give my car what it needs. where i live, 91 is always 20 cents more a gallon than 87. given i fill up every time its at half, thats a three dollar savings. is your engine worth more than 3$ every week? i hope so... if your gonna run 87 oct, you might as well put in havoline conventional oil thats 89 cents a quart.

 

Does anyone have a reliable source that explains the change in hp or mpg that would result from using 87 or 89 octane rather than 91 octane in a 2009 3.0T. I am sure Audi engineers know the answer.

 

idk what the question is... i run 91... or when i used to live in tennessee 93 octane in all my cars.. they run better, seem more peppy and responsive and have a lil better mpg.. if ur gonna run 87 at least do 87 shell.. dont do ampm or those local convenient stations, those are the worst... but best of luck to ur motor

 

https://www.audiforums.com/forum/sho...remium+regular
...

 

Well, I usually put 91 (I hate Kansas) and the one time I put regular in to save a couple bucks, a coil pack went bad. Might be completely unrelated, but I still learned my lesson...

 

Read the manual. It says that 91 is recommended but you can still use 89 or 87 but the mpg and performance will be slightly decreased.