[brucepick]

Well - jcfdillon's suggestion to find some workable way to help move the gas out of the system might have some merit, if the effort to move that gas is causing a reduction in the system's fuel economy.

I think the whole reason that this topic gets (some) attention is that in the performance world, getting rid of lots of exhaust is an issue. In my not-so-humble opinion, here in the fuel economy universe, it's not much of an issue. We're running our engines at about 1/4 to 1/3 of red line max rpms, and at maybe 1/4 to 1/3 throttle, when we actually are running our engines (see "Engine Off Coasting" = EOC).

When you also consider that the energy to run a fan or whatever would have to come from the same engine, I don't think there's much to be gained in worrying about what to do with a tiny bit of exhaust.

Unless you find a way to harness its energy efficiently. That's another discussion.