I have an '06 Malibu Maxx SS. I get lousy mileage 'cause I got the warmed up LZ9 engine. Looking under this car, which I love dearly, I see a really restrictive exhaust system. Will a free flow system help significantly. Also, same question for a cold air box on intake and/or one of those aftermarket computer chips. And, finally, what is legal to modify in today’s engines.
I see a really restrictive exhaust system. How can you SEE it. Few if any modern cars come with a restricted exhaust system today. Back in the 50’s & 60’s It was easy to help out the engine with a less restrictive exhaust system. However today’s cars have well engineered systems. While looking at them might seem to say restriction, in real life it is rare. I would be very surprised if changing the exhaust is going to help you.
However if you are looking for more noise, that is possible.
Thanks, Joseph, how about performance chips and cold air boxes?
Incidentally, the reason it looks restricted is that there is only one pine running back and passing through a common muffler (?) which is mounted perpendicular to the rear bumper. Then there are two “can” sticking out the back which I guess is a cosmetic touch.
You’re right about my notion of exhaust restriction…I’m an old dude. First car I had was the oricinal Chysler 300C which I had in 1960 before I went into USAF. Did not want the be drafted into the Army.
Aftermarket exhaust systems, cold-air intakes and chips may give you a little better performance and negligible better mileage. The small increase in mileage will never pay off the cost of the “upgrades”. Want better mileage? Sell your car and buy something more fuel efficient.
Twotone
Not much you can do here. You might gain a few hp at wide open throttle with a CAI and/or a cat-back exhaust, but I’d be surprised if it makes any difference in mpgs. I’d be very suspect of any ‘chips’ you find on the internet, the only way to ‘tune’ these is with a laptop and a dyno.
most of those “chips” you see are nothing more than 5 cent resistors they are selling for $30
Define “lousy mileage”, as it’s a subjective term. My Bronco gets about 9-11 MPG, which is okay in my book for what it is. My supercharged Mustang GT gets about 18-22 MPG, which I feel is quite thrifty for a 400 HP car. Anyway. Your stock exhaust may be a bit on the restrictive side (though certainly not a restrictive as the stock exhausts of 20-30 years ago). GM had a habit of using the same exhaust system no matter what engine was under the hood on a couple models (per the bean counters). An aftermarket system will make it louder and may free up a few horsepower (think 3-8 HP) but it won’t get you any greater fuel mileage.
Since this is an OBD-II compliant car, any ECU tuning will likely be done with a laptop or a hand held tuner. “Chips” really aren’t used today. In any case your vehicle is already setup from the factory for optimum fuel economy, the auto makers have CAFE standards to meet and if they could squeeze even 1/10 MPG out of the engine they would’ve already done so at the factory.
Many people would go aftermarket exhaust with cars like the 96 Impala due to excessive weight with the cat.