How much Sea Foam should I use on my Buick Lacerne with 232,000 miles? [SOLVED]

Good question, Craig. I’d use the High Mileage version as it’s made to be strong cleaner for vehicles with higher mileage. The standard Sea Foam Motor Treatment would work as well.

Here’s what I’d do: wait until the tank is low (1/4 -1/8 tank), and add the whole 16 oz can. Then, drive until almost empty before refueling. A high concentration like that works very well for cleaning fuel residues and deposits, keeping your Buick’s fuel system clean and running strong.

You can do that every 3,000 miles or a few times a year. It’s fine to add a can more frequently if you’d like, but every 3,000 miles or so will work well to keep things clean.