RE: tmaxx tuning
Use ONLY air filter oil. It is made just for air filters so that the dirt will stick to the oil and not make it through. Using other oils, like motor oil, can allow dirt and other damaging material through, and you don't want to trash your engine to save a few dollars. As far as how much, I do mine to were they are an even color, or in the case of the motor savers, I over oil it, and then squeeze the excess out with some paper towel. Also, with the motor saver filter setup, I only oil the innermost foam element. The outer element stays dry because I use it just to catch the large junk when in sand, and blow it out from inside to out between every tank.