i have a 5sp standard '95 toyota 4runner. it gets decent gas mileage for a 4wd suv (15.5town-17.5hwy), however, i have noticed that if i am running it at higher rpms, like on the hwy or while towing a trailer, (3.25+) w/ the skylight&tailgate window open (which i do often on nicer/ not sweltering days if im out in the country), i can smell partially burned fuel whenever the wind is blowing from the left... theoretically that would mean that there is something i could do to make it burn fuel cleaner/more efficiently. any experience on k&n, some sort of bigger air intake, etc?