I bought a '01 Allroad in May of '06 (2.7T) w/ 84K, put on another 30k in 20 months.I always fill the tank andtrack mileage, 23.5 hwy and 19.5 city... very consistant over first 15 months. Now mileage is consistantly at 18 Hwy and 15 city. No computer faults, no repairs over 30K, just plugs and filters at 90K, new highway tires at 108K. Motor idles and runs smooth and has same power. Only thing of note is the motor is noticeably louder at idle, sounds like valvetrain noise (adjustments?). Do most of own work, anybody out there with similar experience/characteristics and likely remedies? Any and all input is appreciated...Thanks, Greg

 

Any chance that the air temperature has dropped recently? This is exactly (down to the numbers) what happens to my Allroad (and my Volvo, Porsche, Toyota truck, etc) every time the temp drops below freezing. Cold gas doesn't burn well and therefore the engine is less efficient.