My son’s car is getting 15.7MPG AVG and wondering why. For context he is a high school senior and only drives from home to high school on local roads. Also, he also just recently in the last few months started using regular unleaded because of the gas prices and said he doesn’t need the performance.
Could it just be that it is only local driving and the 87 octane that is bringing the mileage from the 20’s to 15 or could there be another underlying issue.