Interesting observation and gas mileage I've never heard of achieving with our cars, unless its a six banger (care to share your secrets?). The real question you should ask yourself is was the car more fun to drive in trip 1 or 2? Another point to consider is you only have 1 data point to compare. Its never a good idea to base your judgement on one date point only. Would recommend at least 3 ea (leave cam in place and just do 3 trips/same route and look for repeatability). Use shorter trips, but all the same route, get the same fuel, etc.