We've all heard them-the stories and myths that abound in the automotive world. Some of them have a factual basis that now no longer exists, so let's explore some of them.
1. If you set a battery on a concrete floor, it will discharge. You must set it on an insulator such as a rubber mat or a piece of wood.
Actually, this was once somewhat true. Battery cases used to be made of a bakelite case and rubber/tarlike material top that was just a little bit porous. When set on the relatively cool cement floor (as compared to air and battery temperature), condensation would form both on the top and sides of the battery. This would allow a path for electrical current to flow from the battery post to the "ground," or in this instance, the concrete floor.
2. By "blipping" the throttle before you shut off the engine, it would start quicker the next time.
I'm not sure where this myth came from-maybe from the days of updraf carburetors that didn't have accelerator pumps. Blipping the gas pedal would pull a bit more fuel up towards the cylinders, which in turn didn't get burned and then would flow back into the carburetor, where it would stay in a vaporized form at least for a short time, thus making starting easier.
All it does in a motor with a downdraft carburetor is put unburned fuel into the cylinders, where it runs by the rings, washing oil off the cylinder walls and diluting the crankcase oil.
Just a side note: On a fuel-injected engine, pumping the gas pedal when starting has little to no effect on fuel delivery. The computer and its sensors are what determine the fuel flow.
3. Mothballs added to gasoline is like adding nitromethane.
Wow, this was a great one. Depending on how much performance you wanted, you just added more mothballs!
Well, mothballs are flammable, and they do smell like they should do something to the gasoline. Actually, they're made up of naptha, which is a petroleum product that vaporizes somewhere between gasoline and kerosene. In reality, I think that mothballs are processed from coal tar-yep, a nasty, sticky substance. In reality, mothballs actually lowered the fuel octane rating and gummed up the fuel system.
4. Sugar in the gas tank = grenaded engine!
So you had a real grudge against the guy who stole your girlfriend away from you? Pour a cup of sugar into his gas tank and the magic of chemistry would seize the engine solid. Or was it that you had to use a couple of pounds?
Nope, didn't work when I was in high school, and it doesn't work now. OK, it will make a sticky mess in the fuel system and plug up the fuel filter, but all you really get out of it is the sweetest smelling exhaust in town.
5. Finally, my favorite of all: It's important that you periodically change the air in your tires.
OK, most of us really do that with our trail vehicles on a pretty regular basis. In fact, when you think about it, we do move a lot of air from one location to another. One would think that a permit would almost be necessary. I fill my tires in Montana and head to Moab, where I lower the tires to trail pressure, releasing the Montana air. When I head home, I fill the tires with Utah air, which I eventually release on a Montana trail.
Back to the myth that air has to be changed periodically. It used to be that there were "service stations," not just credit card pumps. Some of these stations treated their air systems with about as much care as they did their restrooms. Moisture in the air would be drawn into the compressor and eventually collected in the storage tank. Yes, we all know that you have to drain the tank every once in a while. But this didn't always happen as often as it should. After a while, so much water would accumulate in the tank, it would get transferred into the tires.
When tubeless tires first came out, they weren't all that great about holding air, so they had to be refilled often. When the air leaked out, the moisture stayed in. It wasn't uncommon to have half a cup of water in a tire. I've seen as much as a full cup! Small amounts of moisture don't cause much of a problem, as it would distribute itself around the tire under rotation. But a half cup or more presented a balance problem. Then if it should freeze ... well you can figure out that problem.
Yep, there are a lot of automotive myths floating around out there. Got one you would like to share? If so, I sure would like to hear it.