[oil pan 4]

Doing some light reading on belt systems I found a few things.

After reading an ACdelco pdf on alternator efficiency I found that alternator belt power transmission efficiency is some where around 98%.

I have since found another source that back this up and explains belts a little more indepth.

This 98% efficiency only applies to cogged or notched V-belts. Note Cogged and notched V-belts are not synchronous or timing type belts.

These cogged or notched V-belts offer up to a 5% efficiency savings on standard V-belts. Your typical noncogged V-belt can be found on air compressors and riding lawn mowers. These notchless V-belts are usually labled "heavy duty" or "industrial".

This makes me want to swap the belts on my lower powered 1 and 2 horsepower air compressors. I built and rebuilt all my compressors so they all use the same size belts now. Any belts replaced would be set aside as spares on the 4hp compressor that I can smell the belt getting hot when I run it for a long time.

It does not appear that serpentine belts offer any efficieny improvements over cogged V-belts in basic pully systems.
This is because serpentine belts require around 20% more tension than V-belts to do the same job.

I believe the reason people claim serpentine belts are more efficient is due to a matter of prespective.

Say you have 5 or 6 pulleys to run under the hood on a vehicle. If you can run them with one serpentine belt that will be more efficient than running 2 or 3 V-belts. Just because the simple fact that one is less than 2 or 3.

Serpentine belt setups transmit power to pulleys that only have a small radi of belt contact. Something that is not really an option with V-belts.

So if you are only running 1 pulley under your hood you may be better off with a V-belt over a serpentine. That serpentine belt will need more tension which will cause more wear. I have seen this wear in the form of totally blown out front main seals and worn front main bearings.
Having 20% more belt tension on the crank pully from one serp belt is much better than having your belt tension 2x or 3x higher because you have to run 2 or 3 V-belts going around the crank to run all your junk.

This is why we have mechanical engineers.

I may have to try do a test where I swap out a heavy duty belt on my 1hp compressor for a cogged V-belt. Test for a difference in motor wattage draw and compressor RPM, looking for less wattage and more compressor RPMs.