The braided design offers several key advantages for automotive applications:
Danger: Geek out ahead...
One's gotta be careful with the Interwebs. The gist of this point is completely correct, it's just that the details are woefully lacking in correctivity. A big pet peeve for me is incorrect language when explaining electricity, since so many people have such a minimal actual understanding of its physics or its application. Every time something is read that is worded badly, true understanding is diminished.
The EMI mentioned in that quote is everywhere in our rides. Spark plugs, points, generator/alternator and motor brushes, switches, relays... All of those devices produce sparks. The sparks themselves, and the phenomena that produce sparks also induce EMI.
EMI = Electro-Magnetic Interference
RFI = Radio Frequency Interference
RFI is a subset of EMI. Think - all thumbs are fingers, but not all fingers are thumbs.
One needs to have a basic understanding of electrical circuits for the following to mean anything.
Braided straps do not "absorb" or "suppress" high frequency EMI. The result of their behavior in the face of EMI might be "suppression", but to say that they perform suppression is overstating the reality. Instead, they present a good low impedance path back to the voltage source - the battery. Skin effect is the big reason. Skin effect has zero to do with the cross sectional shape of the flat strap vs a round conventional cable. It is the tiny strands of the braided strap vs the comparatively large strands of the cable that matter here. Skin effect acts relative to the individual strands rather than the complete bulk to the cable assy. For a given total cross sectional area of a stranded wire, the more smaller individual strands used to make up that total wire size, the greater the total individual conductor surface area. Skin effect causes the current to flow more toward the outer surface and less to the center of an individual strand of conductor with increasing frequency. The more current you push through a given cross section of conductor, the more impedance you encounter. The more strands you give the cable, the more conductor surface area you get for that current. The more surface area, the lower the impedance, the lower the impedance the less impact the high frequency noise has on the rest of the system.
The example of the benefits of low impedance in the face of EMI are capacitors. Capacitors are used to quiet noise in your stereo because a capacitor presents low impedance to high frequency signals. If you place a cap right at a noise generator - e.g., right at your alternator - you present an easy path to ground for that noise - before it goes throughout the rest of the electrical system. If you place it at the stereo, you give a low impedance shunt to ground for that noise just before it enters the stereo. Quieting it at the source is better than waiting to get it at the point of use, but both are valuable.
All of this goes to the reason that properly located appropriate grounds are REQUIRED in today's modern computer controlled autos, and this is why (in a computer controlled ride, or one with a stereo, or one where the factory decided it was needed) straps can't simply be replaced by wires.
End of pet peeve rant.
