I've mostly owned trucks over the course of my life, more than a dozen so far, and always did all mods myself at my dad's shop. (He owned a garage/ car rental/ used car lot for 35 yrs) Cold air intakes were always one of the mods added to all my vehicles, and I NEVER got anywhere the increase in HP or MPG that the manufactures would claim. Tried Volant, Banks, Air raid, K+N all of them, and never did any of them do anything they are promised to. Only very, very slight increases in HP with any of them, and sometimes an increase in lower end torque, but again, very slight. Well, put the K+N Typhoon intake on the ES350, and have to say I am extremely surprised. Went from about 23 MPG up to 26 MPG! The engine is a lot louder on acceleration, but at cruise can not hear any difference. Spoke with a mechanic I know who used to work on Porsche team for the Rolex 24 hr at Daytona, and he told me it makes sense. If you look at the stock intake, it is full of baffles and very constrictive in order to be VERY quite. People paying for a Lexus don't want to hear noises. You put any type of free flowing intake on, and you are going to increase the MPG. I am very pleased, the thing will easily pay for itself in gas in no time at all. This certainly is not an ad for K+N, cause I hate the way they exaggerate their claims about most vehicles, but just some friendly advice; if you want to increase your MPG's, then get rid of the stock intake.