Originally Posted by Turbo Dog

A bypass filter using a 5 or smaller micron oil filter can do a lot for your oil...that is only if you are willing to run the oil until it NEEDS to be changed. Almost everyone is changing their oil long before it HAS to be changed. I deal with large industrial engines that run 24/7 and with good filtration and analysis the oil lasts for several years. It can cost us $10K to change the oil so this filtration is worth the money. I recently ran a bypass filter system on a Cat 3608 that had a particle count of 22/21/15, after only about 20 hours of filtration the particle count was down to 16/15/11. Don't worry about the color of your oil, in a gas engine it darkens from oxidation, but if the oxidation isn't affecting the viscosity is doesn't make any difference. In a diesel engine the new oil will again turn black very quickly unless you flush the engine. Only a small amount of soot will change the color...you have to do a particle count analysis to understand the amount of grit in the system.

Since I doubt any of you are willing to run your oil long enough to "wear it out" a bypass system won't give you a good return on your investment.

You are really looking for the size of particle that matches the oil film thickness in your bearings...those are the ones that can scratch the bearing. Bigger can't fit through and smaller will pass through. It is starting the engine that causes most of the wear. Use a pre lube system if you want to reduce wear. I time how long it takes the oil to reach and cover the top of the engine, then I run the oil pump for that period plus some time before starting these engines. I can routinely get the equivalent of 1,000,000 miles out of them and also hit 2,000,000 miles by pre lubricating them. That is calculated by the run hours times 45 mph which is the average speed a vehicle moves at over it's lifetime.

All in all...oil is a slippery subject.