The “parts and labor” part of a car servicing bill is the standard part of the invoice. It’s also the part that can contain some interesting reading, particularly if you know your car parts. The mysterious ability of car parts to reincarnate themselves is legendary, and sometimes it’s dangerous. When you’re getting a car repair done, it’s advisable to be at least a bit skeptical on principle.

Car parts are often recycled, and that’s not a problem provided the parts are the right parts for their new jobs. Sometimes they’re not. Some parts vary slightly between models, and that can cause problems. The condition of the recycled parts is another issue. Recycled parts can vary from mint condition to absolutely atrocious.

The real problem comes from bad fits in repair jobs. The very minor differences can become critical, if they affect power or steering systems. From a purely mechanical perspective, a difference of a millimeter in parts can make the difference between working properly or working very badly. Those problems can literally be killers. If the parts are also in dubious or so-so condition, it means more problems.

Some types of recycling leave a lot to be desired, too, like old batteries. Batteries really do have a shelf life, and after that, they’re useless. They don’t charge properly and they act up. They’re also likely to conk out on you on a routine basis. You can jury rig jumper leads, do whatever, but the batteries can be real duds. Other electricals aren’t even that good. Strictly speaking, the best approach to electrical repair is to stick in new components, not fiddle about with something that already wasn’t working properly.

For electronic systems, the short answer to “parts” is Forget it. These systems literally operate the car, and mistakes aren’t likely to be pretty. Electronic parts have very short generational shelf lives, and they’re usually not up to speed with newer systems after a while. The electronics in this year’s car may be OK for some parts in next year’s model, but after that, they’re not an option and would have to be fully replaced anyway. Just get the current stuff.

Being cheap about car service just isn’t a good idea. Any problem can be lethal with a car, and as all drivers know only too well, near misses are usually a result of both cars being able to perform. It doesn’t take a lot to turn a shopping trip into a trip to the hospital, and that’s definitely not cheap.

Cheap and nasty car repairs could generally be categorized as “How to commit suicide without really trying”, as a rule. No half way good mechanic would recommend economizing on performance. No good mechanic would let you on the road with inferior quality repairs. Cheap work is likely to be dangerous work, and even if the whole auto industry would sympathize with the cost of the good parts, they’re well worth the money.

The short answer to any car service issue is to get a good professional job with the right parts. Stay safe, stay on the road, and these things will pay for themselves.