Pair disprove the great battery myth

Dear ACU:
Rob: It's unbelievable how many times I hear this story. I'd like to know who started this myth.
Jeremy: I sure goes back. When I was in high school I worked in a Shell station and I remember one of the mechanics in that shop telling me not to put batteries on the concrete floor - especially when we were re-charging them for customers. They'd drain out, he'd say.
Now, of course, there was a kernel of truth in what he was saying, but only a kernel. And I didn't argue with him, or get into any big discussion, because he was bigger and meaner than me and, worse, he told me this between bites of a raw onion sandwich - two slices of white Wonder bread wrapped around sliced onions, smeared with hot mustard. I always wanted to get out of his breath's line of fire as quickly as possible. So I never argued with Mel.
Anyway, he didn't want to hear about what I was learning in high school physics. That concrete is a lousy conductor of electricity and that the plastic case of the battery is an even worse one.
Rob: Think about it! If electricity just drained out of batteries, how would anyone's battery ever stay charged while it's in place under the hood? Welcome to the world of Popular Myths That Haunt the World of Cars.
Jeremy: Now here's a thought. Why don't we dispel some of the more common myths that I'm sure many people will recognize. And we can start with the battery/concrete issue.
Myth 1: "A battery left on a concrete floor will discharge right through the concrete." The next time someone tells you this, pull up a chair and have them explain why a battery won't discharge when installed in a metal tray under the hood of a car. Certainly metal must be more conductive than concrete.
Rob: Here's the Truth to the Myth: When a battery is left on bare concrete, the cold temperature reduces the charge state efficiency. We're back to physics. Cold molecules aren't as bouncy and full of life as warm ones. So, a battery must be placed on a piece of wood - wood that acts as a thermal barrier to the chilly concrete.
Jeremy: Myth 2. Change your muffler to make your engine run smoother.
Rob: Truth to the Myth: changing the muffler will only make your engine sound as though it is running smoother. This can be filed under "smoke and mirrors". A muffler cannot in any affect way how an engine runs unless it is plugged solid.
Jeremy: Myth 3: Now here's one I'd like to believe, even though I know the truth behind the myth. Anyway, here goes: washing your car will make it run better.
Rob: Yeah, well under Truth to the myth see changing your muffler.
Jeremy: Myth 4: Clamping a magnet to the fuel line will make the engine run more efficiently.
Rob: Truth to the myth: All sorts of tests have shown no effect on the running characteristics of an engine with a magnet attached to the fuel line. There's no impact on emissions, either.
Jeremy: Myth 5: Our mechanic tells you, "Sorry, but your car needs a new computer."
Rob: Now this might be true; computers do break down and when that happens it's a very, very expensive part to replace. But the Truth to the Myth is that nine times out of 10 the on-board computer in your car is the LAST thing that needs replacement.
Jeremy: Myth 6: My car is a lemon. It must have been built on a Friday.
Rob: Truth to the Myth: Assembly plants work on shifts and the schedules of those shifts change according to market demand. The production lines of popular cars and trucks run seven days a week, as much as 22 hours a day.
Jeremy: A lot of things can have an impact on the build quality of any car, but the day of the week isn't one of them. Anyway, Myth 7: You need a transmission overhaul because the shop found a small pile of debris in the pan.
Rob: Truth to the myth: Now this is a common one - and it can be costly to believe it - as much as $2,000 or more to the unwary consumer. So let's set the record straight: A small pyramid shaped pile of brown debris is absolutely normal; you'll find it in the pan of any automatic transmission that has been in service.
And it makes sense when you think about it. Through normal usage, bits of friction material wear off and get deposited at the base of the drain-back outlet inside the pan. Over time, this builds up and should be considered as par for the course.
Jeremy: Myth 8: You need new "muffler bearings". Now I like this one. It sounds so sensible, so believable.
Rob: If you like bafflegab. The Truth to the Myth: There's no such thing as "muffler bearings".
Jeremy: Myth 9: This car is a great deal; it's only been driven on Sundays, by a kind little old lady who never went faster than, say, 50 kilometres/hour.
Rob: Truth to the Myth: In actual fact, a car that isn't driven at least 800km a month could wind up with serious dirvetrain problems due to lack of use. This goes for important things such as the brake system as well. Condensation can also build up in the fuel tank, causing very expensive repairs down the road. Cars are meant to be driven. Period.
Jeremy: And here's a great one: Myth 10: A new car owner is told, "Don't worry; it's okay. That noise you hear in the engine will go away once it's broken in."
Rob: Truth to the myth: I know of no mechanical noise, with the only exception of forged pistons, that will go away over time - especially an "objectionable noise". Remember that we're dealing with metal components trying to rub up against other metal components. If you hear a noise, it won't go away; but it will get worse. Especially with a new engine. As soon as a new engine is started for the first time, the parts inside begin wearing out.