How about the sludge monsters?

Some modern vehicles may be sludge monsters-apparently the vehicles are designed to run so hot to increase fuel mileage that conventional, and even synthetic oil, breaks down and sludge forms in the engines. There has been a considerable amount of discussion about sludge forming vehicles on the internet-some cars, vans, and perhaps trucks and SUVs seem to be prone to this sludge formation. Is it possible to extend oil changes on vehicles like these, perhaps using a motor oil like Schaeffer's Oil and a product like Auto-RX? Or, if a person is driving a sludge monster, are 3000 mile oil changes better?
Auto-Rx, Lube Control and Nuetra seem to have very good oxidation controlling capabilites. We tested Exxon Superflo 5w-30 and Auto-RX with fantastic results. 5 qts with 3 oz Auto-RX out to 7741 miles in a 2001 Toyota 3.0L V6 with 17% oxidation. The cheaper oils do exceptionally well with RX. The higher end syns "seem" to do well with LC. I haven't yet tested Nuetra in crankcase applications except to flush minutes before a oil change. Tested Schaeffers 5w-30 with Lube Control past 15,000 miles , one filter change during test, AC PF 1127. [ April 27, 2003, 11:23 PM: Message edited by: Terry ]