I find better running in the outlying areas too. And better mileage.

You're on to something. There are a LOT of newer cars on the road now, with a pretty decent economy over the last few years. And the ones that aren't, are often pretty tired anyway, so you'd hardly notice such a buildup.

But then again, it isn't so common as to cause problems all over the place. If it was, people would be screaming bloody murder about this.

One thing I have found is that short-tripping with the rotten gas is not a good idea. Two cars in two days (740T and Rodeo) locked up after extended periods of idling, and then shutdown. The Rodeo was used/driven a little bit here and there, and then shut off. Then, the 740T fell victim to part II, when it was short tripped and shut down again. And the same thing happened--#2 intake and exhaust locked up. The problem multiplies as the cylinder combustion temperature goes down as a result of poor combustion.

I think the simplest, most easily administered RX, would be only to take the thing for a highway drive every few days. Not much, maybe 20-30 miles, with some good, heavy throttle thrown in for good measure. And something to really fire up the combustion chamber, like a nice long climb at moderate RPM. I personally drive about 400-500 miles a week, with most of it being solid 40 mile trips on the highway. Often at 80-90mph. In fact, the closer I cruise to 90 (or 3000rpm) the better the car feels for a few days thereafter. If I loaf the trip, or end up in traffic at 60mph, it feels pretty much the same.
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Chris Herbst, near Chicago, IL. 93 940, 91 240, 90 240, 88 740, 87 240