I had one....along with snorkel,Exhaust, chip and LPG injection. With stock filter vs K&N i got 50km extra per tank of Vortex with the K&N in. Power wise couldn't notice much but with the chip exhaust and LPG on the extra power if any would be very hard to notice- never got around to stock vs k&n on the dyno, wish I had before the beast went to Hilux heaven....or hell depending on how u view the things. Other driver should go straight to hell though [POUTING FACE]
Next customer I install one for though ill be sure to do a dyno comparison....I'm interested to see now