I agree that (1) you’r eprobably fine and (2) an occasional bottle of gas stilizer wouldn’t hurt.
As to whether you got better mileage on your trip, you probably did. However it can be almost impossible to differentiate between actual improvement and perceived improvement. My feeling is that it doesn;t matter. If you had a good trip, and everything’s running great, than be happy. If you believe you got better mileage, or get better mileage for having gone on the trip, than enjoy the moment. Take more trips.
Life’s short. There are two rules:
- don’t sweat the small stuff
- it’s ALL small stuff.
Happy motoring.