Speaking of oil changes; has anyone gone to a system like the truckers use which only replaces the element of the bypass filter and adds oil as needed but does not require regular oil change?
The engine oil gets contaminated and breaks down with use, it needs to be changed regularly. Of course filter out the dirt it collects is a big part of preventing engine damage, but I can't imagine filtering doing anything to extend the life of your oil.
Only two ways I'm aware of extending your oil changes, without hurting your motor. Keep in mind, the design of the motor will dictate the viscosity of the oil and the oil change interval, i.e. older, cheaper motor designs used thicker oil and required it changed more often compared to newer, more sophisticated and cleaner motor designs.
1.) Use a higher quality oil (like Grp III Synthetic or even more life with Grp IV Synthetic).
2.) Use some type of monitoring system, either software in PCM monitoring usage of the motor OR oil analysis, etc. To warn when the oil needs to be changed. (without a monitoring system, people often change their oil too early, to avoid the risk of running on contaminated/broken down oil.
So, what I suspect (I could be wrong) you're talking about is big fleets of large expensive trucks that it is worth the investment of a more sophisticated multi-filter oil system that is supported by the Fleet's Maintenance and Monitoring. And likely they use a superior oil that out lasts the filter and thus they monitor the oil and change the different filter elements periodically. In the long run with a big "well managed" fleet, it saves them money.
If you visit AMSOIL website, you see they offer oils they claim will last a whole year or 36k miles or more in your engine. They recommend changing the filter several times during that 36k miles and topping off for the oil lost during the filter change. They also offer oil analysis services to periodically mail in a sample of the oil and they will email you back if they find anything bad in it or anything indicating its contaminated/breaking down and will need to be changed soon. (This sounds close to what you're talking about
The most practical oil system for typical car owners, is the one installed on your Jeep's motor. I'd use it and follow the manufacturer's recommendation to the letter. If you're NOT a typical car owner and would like to do something else, by all means do so, look into the different systems that could be adapted to your vehicle, but follow the manufacturer's recommendation to the letter. AMSOIL is the only that comes to my mind.
Don't get the impression that because some big rig truck that has some sophisticated oil system, would work for your Commander. Putting a different oil handling system on your motor doesn't change the oil change interval, the motor and usage is still the same, and its the motor its wear and its usage that determines how quickly the oil gets contaminated and breaks down. Changing filters does very little to change the oil condition, I think what your getting backwards, if you use ultra-quality oil that resists contamination and breaking down much longer than conventional oil, you may have the filters collect enough dirt to start clogging, and you'll have to change filters before the oil.