cant say i dont agree with the "search" folks in the thread. because even googling will take you to about 100+ post about this very subject. but in the spirit of answering, i also agree with bob again

in the grand scope of power mods, the 5hp you will gain from a JoeZ or F Sport intake you wont be able to feel anyway. but it will give you a sound increase. the only way i realistically see you losing MPG is from being foot to gas everywhere because of that "new mod must hear it" thing you get with cars

 

With Joe Z
* I saw that they dyno proved about a 6 HP increase on a RWD Manual. Close to the same on a AWD automatic?
RWD on average has 15% power loss to the wheels, AWD average 20%. you do the math
**Do you know what's BHP vs. WHP? You already stated you found dyno with proven 6 HP (which is WHP) gain on a 6MT. 6 / 0.85 equals to about 7 BHP gain. 7 * 0.8 equals about 5.5 WHP gain on AWD. These are just theories based on generalization. The 250 did indeed get 6WHP gain while the 350 about 4WHP. Averages out to be ~5WHP gain from both intakes. 4, 5, 6, or even 10.........you're not going to feel anything. Since this car is N/A, the climate has a much bigger affect on engine performance than an intake.

With F-Sport
* Are the HP increase the same as the Joe Z?
Yes. Same thing (a pipe) with a redesigned stock airbox that has a hole behind the headlight area. Also uses a dry filter

I have a 250 AWD. It's not fast; I don't race; I don't mod for performance. But I mod for sound, some cosmetics, and digging into suspension/handling. I still have fun with the car when I gun it and the exhaust/intake go vroom vroom (placebo effect FTW), as well as cornering and entering highway ramps.

 

IMHO you're not bothering anyone and I would like to add that I am new to this forum as well AND not familiar with mods OR Lexus'....half the fun is the discovery!

I have a 2011 IS250 RWD that I'm getting ready to mod and have done some research on the intakes and power gains. Please forgive me if someone else has addressed this earlier in the post...I stopped reading when the air was getting a little tense.

SO from what I understand power gains are measured on a dyno from which both intakes have been tested involving horsepower and torque. If you are unfamiliar with how this process works, here are a couple of links that may help:
http://auto.howstuffworks.com/horsepower1.htm
http://www.proimporttuners.com/pages...ing/index.html

I am in the planning stages of the mods on my IS250.
What is important to me is cost versus HP gains.
Both the intakes you are asking about give relatively the same HP gains but the JoeZ costs significantly less. Sound is less important to me at this stage.

There is an argument to be made that the F-Sport series of parts give pedigree and therefore retain the value of you IS250 which I would tend to agree with. For example, if you tried to sell your car with F-Sport series parts versus other non-Lexus brand aftermarket parts, chances are you will get less for your car using the latter. I think most people keep the OEM parts to swap back to when selling.

Are you trying to get a louder more aggressive sound?
I prefer a stealthier approach where I get the HP gains with little to no difference from the way a stock IS sounds.

I just purchased a JoeZ intake and should be receiving it shortly (after the snow storm passes).I will let you know how it goes and what differences, if any, I notice. In terms of HP, technically speaking, a dyno is the best way to measure gains...or maybe doing several passes at a track and extrapolating from there but that leaves room for many variables.

Even though it comes with an air box, I decided against the F-Sport intake because I am mainly focusing on performance and not sound. The IS250 OEM airbox is designed as forced "cold-air" coming from the front and thus, the F-Sport air box adds only a different sound with no other performance gains.

Hope this helps!

 

From what I have read it sounds like that the Fsport will give you a throaty roar, which is what I am going for when considering mods