2005 Audi A4 Quattro Q&A
2005 Audi A4 Quattro Question: Engine sluggish in morning - need octane upgrade?
The dealership checked and said everything is firing ok in the engine. But, the first 10 minutes are sluggish in the morning. Someone suggested that the Quattro needs the highest octane level of gas, could this be the problem? (I'm using the cheapest grade) - Ladybug Driver
Audi certainly recommends using at least 91 octane gasoline in their engines, as they are high performance. You car, however, will operate perfectly on 87 octane and what you would most likely experience is some horsepower loss. RepairPal has some additional information on the trade-offs: http://repairpal.com/regular-gas-is-it-ok-to-use-in-your-car The best thing to do is to switch to 91 octane and test whether you experience a difference. - matte
cheap gas usually does not contain much detergent and may have too much ethanol. both can cause power loss due to mixture and deposit problems. do not use dry gas (more ethanol) but do use some type of fuel system cleaner (techron or the stuff audi sells). - some guy