Aftermarket exhaust and k&n intake?

Question

can you get better fuel mileage with these aftermarket upgrades what are the benefits of doing this it is going to be done on a 05 Tahoe are there any other benefits other than a deep rumble?

Answer 1

As you have seen from these answers you will get a very mixed review.some may come from a person that had good performance with a product or possibly very poor, some that have never even used or tried any of what you are asking but answer from books . My personal view is that anytime you make a engine breath easier it will run stronger and more efficiently but you need to make sure all the other things are up to spec's also like oil changes, tire pressure, wheel alignment, and driving habits all add to better mileage. Company's like K&N Filters and Magnaflow Exhaust do a lot of research into their products to insure that they work as close to the claim they make of them ( for the customer satisfaction and their companys good name ). my advice to you is ask the people that make the products.(Read the About Us sections of their companys at the web sites and testing and research sections also ) talk to the people that use items you are looking into buying, I'm sure you have someone in your area that runs some of what you are looking for. remember this is just online advice not the golden rule Opinions will vary like night and day.

Here are two links that you may find useful. hope they help

Answer 2

Robertis is exactly right. If you want better gas mileage, you need to change your final drive ratio, fiddle with cams and injectors. In other words, it's really, really hard.

Anyone who tells you that a K&N filter is good for the car in any way is either a huckster or a fool. Paper filters aren't especially restrictive, but anything that gives you better flow does so at the expense of less effective filtration.

As for less restrictive exhausts, don't walk away, run. A well tuned exhaust (which most after market products aren't) can indeed improve the breathing of your engine. But if you manage to move more air through the motor you also need to move more gas. So why anyone would tell you that you'd get better mileage is beyond me. It never, ever happens.

If you were going to work on exhaust, then you would get the best bang for the buck by installing headers, not a cat-back system. What you need to understand is that headers can be tuned by optimizing performance in a very narrow RPM range. Stock exhausts are usually tuned to give you best performance between 2000-4000 RPM, where you really need it. Performace exhausts can make more horsepower, but it's going to come at 5000-6000 RPM. Great if you plan on cruising at 120mph. Worthless otherwise.

Behind the cat, almost nothing that you do will matter. Unless the system is totally restrictive, there is no point in increasing the diameter of the pipes. Big pipes actually result in slower flow.

You need to be very concerned about your O2 sensor, as Rick M suggests. The O2 sensor regulates fueling. If your exhausts relocates the sensor, it may not operate correctly. And if it really produces a lot more flow, the injectors may not be able to maintain mixture strength. Bear in mind that all of this affects your emissions, and you still want to be street legal when this is done.

Answer 3

The duo of exhaust and intake claim to increase mileage by 25%. I work for a chevy/Hummer dealer and have never seen an increase that steep. If it were true we'd be putting exhuasts and k&n filters on Cobalts! You can expect--maybe--a 10% increase in economy. Maybe. You have to watch it, though--some GM vehicles' O2 sensors will no longer allow an aftermarket intake kit--it triggers a malfunction in the computer system. If you do the math, installing these makes at best borderline sense--unless you just like the sound!

Answer 4

It allows your engine to breathe easier. This increases power and fuel efficiency. You could expect a significant increase in mileage.

Answer 5

any time you see anything that says better fuel economy, don't expect it: you have to tear apart or replace the motor with a smaller cam, intake, etc or get a transmission that has more highway friendly gears or a higher ratio(lower number) rear end.