Do you use engine, fuel additives to your vehicles?

i change my engine oil on a regular mileage cycle, same for transmission but I do use an engine additive when I'm going on a long road trip and the same with a fuel additive. In the winter I will fill up with a higher octane gas once or twice a season.

I've heard some mechanics say they use Lucas fuel treatment religiously. Also have read on Jeep forums about people using some Marvel Mystery oil to help clean/quiet lifters. Older Jeeps used flat tappet lifters which are notorious for being a tad noisy.

Seafoam can be used by mechanics/dealerships (as a bandaid fix) to clean injectors before selling vehicles too. You can find all kinds of videos of people doing seafoam cleans on youtube because your car smokes like crazy.

No. Get oil changed about ever 5,000-6,000 miles.

No. Regular maintenance is all you need.