I'm running an Amsoil dual by-pass filter now on my Ford truck. This is the second vehicle I have run one on the the first perfromed as promised.
The biggest benefit is easy oil changes. You need only to change the oil in the filters, and not the oil in the pan. In my case the filters are easy to get to, but that may not be the case on an Escort or Protege.
The second benefit is the reduced wear. The claim is significant reduced wear, tests have shown it and my results were spectacular. You can drive an engine 150K or more with out a by-pass, but your engine will run more like it did when it was new with it.
The third benefit is that it won't cost any more in the long run because you only have to replace 4 quarts of oil and 4 filters a year. Also, it's easier to run an expensive oil like Amsoil when you only have to replace 4 quarts every year.
Besides that, your oil is clean all the time. You never drive that last 500 miles on dirty oil before the oil change.
On the down side? First, Were are you going to mount this big dual filter rig? Second, the up front costs require you to keep the vehicle for a while to get to the break even point. Third, it is one more area to watch for oil leaks.
By-pass filters are best suited for large vehicles with large oil capacities. It's tough to run Amsoil in a truck that takes 6.5 quarts of oil, or a semi that requires 20 quarts.
If you can't find a place to mount a dual by-pass a better choice would be a Trasko filter which has the dual filtering media in one filter that mounts where your standard oil filter mounts. I haven't tried it, but it is the same technology. The filter is about $70 and $10 each change after that. Thanks for asking.
