Hey el_d_m, just purely out of curiosity, not that I am saying you are wrong, but do you have actual numbers that back up your increased fuel economy?

I would honestly like to try an experiment with normal daily driving for about 5 tanks each configuration, to see if there is any difference with the K&N vs a good paper filter, with and with out throttle body spacers, cold air intakes, etc, but I sure donÆt want to foot the bill for all those parts, especially when to me they make no logical sense for any of my rigs.

Actually to any of you out there that would be interested, this could be interesting, we as a group could play a myth busters type roll and see if we can prove or disprove a lot of the gimmick type ôbolt onö performance hop up parts out there. I donÆt know, maybe itÆs just the engineer in me, but a lot of these things like the throttle body spacer just make no rational sense to me. If you take the part back to its roots (a carb spacer) it makes perfect sense. Raise the carb an inch or 2 to straighten out the airflow into a more laminar flow, and keep the carb cooler, and ultimately the fuel cool allowing a denser mixture to enter the cylinders. With most of the EFI engines the throttle body is a decent distance away from the intake, granted on our jeeps it is not, but most of the spacers advertise they swirl the air for better mixture, which doesnÆt make sense if they were trying to straighten out the air in a carbureted engine. That mixed with the fact that the fuel rail is right above the intake valve, and there is no fuel back at the throttle body to mix with the swirling air or to keep cool. Anyway, I am definitely off on a tangent from where this thread started now, sorry about that, just some random thoughts after work I guess, but I digress. It would be an interesting experiment to have though.
Sean