Hi! I bought an 03 Cavalier from my dad a few months ago. He didn’t drive it often as it only had 42,000 on it (yes just 42k). Recently it has started to get poor gas mileage – I’m talking at least 80 less miles per tank in the same repeated driving routine. Would putting this Sea Foam Motor Treatment product in the tank be the way to start working on what’s going on? Thanks for any positive feedback!