Cold Air Intakes

[HSKR R/T]

I can only tell you what the average reading says with my same driving route/mode. It's as close to accurate as I could get. I also agree the exhaust pipe is very well done as verified by my buddy who designs and builds performance exhausts for racers. It was he who noticed the stock muffler is a giant barrel that is not very efficient in air flow and swapping that out with a performance muffler eases the flow restriction. It's basic physics isn't it? Reduce the flow restrictions means more gets out faster/easier. Also means more air can get in. The stock muffler is huge...like 4-6x the size of the super 44. I also agree removing the resonators would help more by further reducing the air resistance, but based on my buddies expertise, he said the stock muffler would have a greater resistance to the flow than the resonators and yes removing them would help but also substantially increase the noise, which I did not want.

In the end, the CAI increases the ability for more air and the optimization of the muffler increases the flow out. Making the engine breath better and burn better. The stock intakes and mufflers are all designed primarily for noise and certain state requirements, not for performance. I would say doing one without the other doesn't usually help, but with both it did on my average mpg reading on the gage.

Hopefully your friend also told you that Flowmaster is one of the worst performing aftermarket "performance" mufflers you could choose.

 

[theblet]

You already have a CAI from the factory. Possibly upgrade to an AEM. You don’t need to change the whole intake system unless you’re heavily modded. IE. cam, tune, super charger, etc

 

[securityguy]

Hopefully your friend also told you that Flowmaster is one of the worst performing aftermarket "performance" mufflers you could choose.

Flowmaster ranks right up there with Gibson...GARBAGE!

 

[Whoa_Ram]

I really don't thing this is the case. Many factors will influence mileage. The OEM exhaust is already a very good exhaust and just swapping a muffler, as a ton of us have done, will not net any real gains in mpg.

Reducing exhaust backpressure can improve fuel economy and performance.

Reducing restrictions in the exhaust system and the air intake allows the exhaust to flow more easily so the engine can breathe more efficiently.

The most common modification is to replace the stock muffler with a low restriction aftermarket performance muffler, or to replace the entire stock exhaust system from the catalytic converter back with a free-flowing aftermarket performance exhaust system.

Yeah I changed over to the Borla 40353 muffler and I've noticed a decrease in MPG's haha. I still keep my light foot and coast like usual, but I've noticed that the truck will downshift now in any little inclines and will go into 6th gear as before it would hold up 8th pretty much the whole way. I've also noticed that now when I coast around 65-70 my instant MPG's would always show 22-27 and now I'm lucky if I see 21 to be displayed. Not complaining and not sure why it's doing this, but just thought I would share. My last 10 fill-ups I averaged 19.4 per fuelly. This last talk I averaged 17.2mpg and this current tank is readying out 18.1.

I have to blame the idling I did on the first tank so this second and third tank will give me the true results. So far I think I've lost about 1-2mpg's which is odd.

 

[Atrophaeus]

Whoa_RAM, sorry to hear about the MPG decrease. That is odd.

HSKR R/T he told me flowmasters were not the best and out of the flowmasters, the outlaw would give least resistance. In the end I wanted to balance the increased flow with the sound I wanted (I have always really liked the sound of flowmasters on a V8). So i choose the Super 44's for the sound while still increasing the flow. It's not the "best" muffler out there, but I also do not want something super loud and the right sound for me. Based on OEM mufflers, the super 44 tends to improve flow by ~100-125cfm. So I was improving the flow while achieving the sound I wanted and all was to complement the intake. I'm not racing my truck so I do not want just the numbers. It's my daily driver so I want it sounding how I want and if I can improve performance while doing that, why not?

 

[securityguy]

Whoa_RAM, sorry to hear about the MPG decrease. That is odd.

HSKR R/T he told me flowmasters were not the best and out of the flowmasters, the outlaw would give least resistance. In the end I wanted to balance the increased flow with the sound I wanted (I have always really liked the sound of flowmasters on a V8). So i choose the Super 44's for the sound while still increasing the flow. It's not the "best" muffler out there, but I also do not want something super loud and the right sound for me. Based on OEM mufflers, the super 44 tends to improve flow by ~100-125cfm. So I was improving the flow while achieving the sound I wanted and all was to complement the intake. I'm not racing my truck so I do not want just the numbers. It's my daily driver so I want it sounding how I want and if I can improve performance while doing that, why not?

There are several high-quality mufflers on the market that will perform as good or far better than a Flowmaster. If you are happy with your choice, then that's all that really matters.