They aren't all the same.What's the engine and what fuel are you running?
Turbo plugs are tapered at the tip and the head/head button is also tapered, it's how they seal. They are made that way to mate perfectly flush to the inside of the combustion chamber. It minimizes turbulence as the air/fuel mixture enters the engine. With a normal plug, they usually sit about flush, but the edges of the threaded hole and end of the plug cause a hair bit of turbulence in there. Turbo plugs are only really for cream of the crop racing needs. A typical basher probably wouldn't even notice a difference. The plugs are also more expensive.
Outside of "turbo" plugs, there are long, medium, short and a range of temps from hot-cold. So knowing what it is you need to put a plug in and the fuel you run is kind of necessary to get an idea as to what will work for you. Fuel nitro percentage usually dictates what temp you want to go with, or at least a range to work in. 20% on down, usually a hotter plug. 25% on up, a cooler plug. High compression/rpm racing engine, probably a cooler plug.
