Review on K&N Engine Air Filter: High Performance, Premium, Washable, Replacement Filter for 2000-2015 Toyota/Lexus V8 Truck and SUV (4Runner, Sequoia, Prado, Tundra, GX470) - Model 33-2144 by Gregory Abercrombie

I always buy a washable filter. If you're just driving down the street, you most likely don't need it. If you swap out paper filters every few weekends after you're away from home, a washable filter is your only option. I can't say you get more power or better MPG, but that's because I have it on a V8 trail setup with spiked tires. Maybe a little more responsive at low frequencies? If you really want noticeable gains, use a full cold air intake (rather than a short piston that draws hot air from the engine compartment). Keep it clean, lube it, they'll last as long as the motor.