We drove our Smogmobile to the Gloucester Nissan garage on Friday afternoon for some routine maintenance, and saw some interesting results along the way. Predictably the NO2 levels were notably higher than in Stroud, peaking with a 1-minute average of 137 ppb (262 µg/m³) on Barnwood road. We also noticed an unusual methane spike on Eastern avenue, peaking at 3.5 ppm, 75% higher than the background concentration. It’s unclear whether this methane was coming from nearby businesses, vehicle exhausts, or something else entirely, but it was certainly an intriguing observation!