Originally Posted by Ben.C
Actually that softens the belt so that there's 'less' resistence....
Another extreme way to reduce the resistence is to clip away alternate teeth... This tip from Japanese Magazine.
How to prolong belt life is proper belt tensioning.
Actually the WD40 trick does not necessarly offer less resistance but it does make the belts more flexable. If you notive the current trend is stiffer belts. The Tamiya "Low Friction" white bets are much stiffer than the stock bets. Schumacher is now back to the stiffer belt (at least when I ran the Mi2, people were not using the softer belt. Corally belts are pretty stiff as well.
I think the idea is that softer, more flexable belts hold onto the pulley more, they wrap around the pulley more causing more friction. A Stiffer belt has a tendancy to not want to grab onto the belt (not sure if I am saying this correctly) so you only need to make sure the belts are tight enough to not skip and you will have a car with a much more free drivetrain.
To make a belt last long is just common sense. Do not bend or crimp. Do not let the belt flip on the pulley or roll over on itself. Do not run them overly tight and make sure they do not skip. That's about it. Do put dressing on the belt or put WD40 on it. Leave it dry. WD40 and other stuff makes the belts softer because it breaks down the rubber causing the belt to fail prematurely. Some may say the if you don't put a dressing on the belt, it will dry rot. Well that is true but it will take a belt longer to dry rot than it will take WD40 to destroy the belt.