Use a K&N drop in whenever its available you can easily gain 1-2+ mpg just from a drop in filter

Impressive! Okay, there's hope! I assume this is with the ect/pwr button disengaged?

You are correct, I rarely flip the "***** out switch." This is not to say I dont step on it, oh I do. I love all the windy backroads and when the roads are wide open Im all game. I just dont see the need to hurry up and wait or race to the next guys bumper waiting at the light ahead in city traffic. This is a move which the misses practices religiously and her mpg is garbage. Just one of the many reasons, I dont let her drive my car.

THANK YOU! Glad to know I'm not alone here..

Wow I wish I would get the mileage you guys are having..

216 miles today with last tank....onboard computer says my avg. mileage is 18.5 mpg with IS350 with 90% local driving mostly short hops (10 miles or less). Guess I need to find a place further away from work so I have a commute

700 mile roadtrip, car brand new, Nebraska to Texas, mostly driving over 85 mph, IS350 averaged 27.7 mpg per computer, and when manually calculated it turned out exactly the same. Very surprised by both mileage and apparent accuracy of computer.

That's great I need to go on a road trip. Only getting in the 18's with City driving.

How often are you flooring it?

uhh I don't know about those K&N claims.....I heard you can take the filter completely out and it wouldn't increase your mileage (or horsepower)...if it was that easy the manufacturers would use them {I saw tests indicating this but I can't remember the site).

BTW - I'm up to 27.6 mpg (IS250) 60% city / 40% hiway.....anticipating & coasting up to red lights and stop signs -- also helps with brake dust

Really? How much are the filters?

hardy ever, I usually let it shift before 4k with the PWR button off. I really think it's all the stop and go traffic and short trips I make. Drive to work is about 15 mins in stop and go traffic (traffic lights than heavy highway traffic sub 40 mph). Lunch breaks are usually 10 mins drive tops, than drive home. That is what is killing my gas mileage I think.

Is the terrain you drive on relatively flat?
Do you ever go pass 3500 rpm? How often?

IS350, and I'm getting about 22 mpg/tank...50/50 highway/city driving.

were city driving, and I averaged 21-22 mpg with 91 octane Shell. Drove to Wichita & back this week, and set the cruise on 70, and voila! the average was 29 mpg for the roughly 400 mile roundtrip! My 250 was silky smooth and quiet as church set at 70. I know that's not enough speed for the younger guys, but no worries with the KHP, and was very curious to see about optimizing mileage on the highway.

My idle is lower than a stock OEM filter on my prelude I gained mileage over OEM junk. My bros 2004 TSX has a drop in filter, on OEM filter he was getting 340-360 miles a tank historically, I put in the K&N drop in and its risen to 380-390 one time hitting 400 miles a tank, my bro doesnt drive aggressive at all so it wasnt a change in driving style. A filter always restricts intake flow and therefore lowers power, but its there to keep the engine clean and make it longer lasting. Racecars dont use filters of course for more power and they dont need the engine to last a long time

~35-40 dollars. Seeing how every 15k if you want to use OEM filters they are 25-30 dollars (maybe more for lexus OEM), however you can keep the K&N the lifetime of the car, clean it off every 15k miles with $10 cleaning kit thats reusable probably 10x.