Has anyone else found a significant decrease in fuel economy the past few weeks as temperatures around MD/PA/DC area have fallen? My last tank was about 19.1 and this tank is looking like 17MPG. OR could it be related to the oil-overfill mid-tank on the last tank? We've had several mornings in the low 30s the last week - wondering if anyone else is finding a drop.

Just a thought -- are you using the windshield defroster? That turns on the A/C compressor (whether you have the A/C button on or not), which has a dramatic effect on mileage.

At any rate, cold (not cool) weather does tend to make piston engines burn with a richer mix; I assume it has the same effect on rotaries.