Bike and Giant Hogweed.
I bought my bike more than ten years ago, and in that time have ridden more than 10,000 miles. I have had a single flat (rear wheel) and today, for the second time, took it to the bike place to have the rear derailleur cable replaced. They're also going to replace the adjustable stem (the vertical part below the handlebars) and tighten up this and that. Cost: $73.40 plus tax.
Ten years ago we bought a car, a European brand known for quality. Over the past year we paid more than $5,000 to deal with what seemed an endless list of issues. The final straw was engine de-sludging. After we relieved ourselves of all that money, we relieved ourselves of that sucker.
Now we have a Japanese car, a nice one that speaks English. It says, "Pardon?" when we ask it to phone someone. It always screws up the phoning part, or perhaps it's our fault; we are the weak link in the human/droid interface. Point is, the car is very polite. And no sludge so far.
I'm happy to live in a flat place with moderate weather. Most years I can ride my bike year-round. My bike is also useful as a metre-stick for ferocious plants (above) and various trees.
Sludge is never an issue.