5.3 GM performance package question

mistaare · January 26, 2020

I have a stock 2020 5.3/10 spd. I have been reading about CAI/cat back exhausts and it seems like people have been getting a little bump in mpg with them but most of what I read are people with 6.2’s and not 5.3’s. I don’t quite get the restrictions with the stock exhaust, resonantors? Flaps? I under the concept of a freer flowing exhaust.

So the questions I have:

1. Anyone install the GM performance package after several thousand miles? If so, what are your thoughts?

2. what are the benefits of the CAI coupled with the exhaust? Is it worth the additional $600+?

3. do people get a little jump in mpg with cat back? Or with CAI and cat back?

4. does the GM performance exhaust drone on the highway? I wouldn’t mind a deeper exhaust around town, but I definitely don’t want to hear it much on the highway.

Any inputs would be greatly appreciated. Like I said, this is mainly for the 5.3 crowd, it seems like there are a ton of you 6.2 owners that have shared your experiences.

I am only interested in GM parts because I don’t what to mess with warranty.

Texasdeere · January 26, 2020

You may like the GM Performance exhaust. Fit, Finish and Quality are top notch. It definitely has a deep tone. At steady throttle with no load it is pretty quiet. Highway cruise very quiet. Any time you accelerate even a small amount you are going to hear it. Any movement of the pedal is going to make a change in the sound. You can hear the DFM working at slow speeds but it's not that annoying. When you decel you will hear an occasional deep pop or burble in the sound. I sounds very good on the outside of the truck but the problem for me was inside the cab the deep tone and sound was just too much. The deep tone just permeates through the cab. If you were to pull a trailer frequently I would stay away from this one.

5.3 with 6500 miles, single side exit, removed after 2 days

mrcribbs · January 27, 2020

22 hours ago, Texasdeere said:

You may like the GM Performance exhaust. Fit, Finish and Quality are top notch. It definitely has a deep tone. At steady throttle with no load it is pretty quiet. Highway cruise very quiet. Any time you accelerate even a small amount you are going to hear it. Any movement of the pedal is going to make a change in the sound. You can hear the DFM working at slow speeds but it's not that annoying. When you decel you will hear an occasional deep pop or burble in the sound. I sounds very good on the outside of the truck but the problem for me was inside the cab the deep tone and sound was just too much. The deep tone just permeates through the cab. If you were to pull a trailer frequently I would stay away from this one.

5.3 with 6500 miles, single side exit, removed after 2 days

Did you go back to stock or another aftermarket system?

Texasdeere · January 27, 2020

I just put the stock system back on for now. Probably going to leave it that way.

mistaare · January 28, 2020

That's great feedback. in that two days did your DIC indicate any better mpg.

On 1/26/2020 at 9:57 AM, Texasdeere said:

You may like the GM Performance exhaust. Fit, Finish and Quality are top notch. It definitely has a deep tone. At steady throttle with no load it is pretty quiet. Highway cruise very quiet. Any time you accelerate even a small amount you are going to hear it. Any movement of the pedal is going to make a change in the sound. You can hear the DFM working at slow speeds but it's not that annoying. When you decel you will hear an occasional deep pop or burble in the sound. I sounds very good on the outside of the truck but the problem for me was inside the cab the deep tone and sound was just too much. The deep tone just permeates through the cab. If you were to pull a trailer frequently I would stay away from this one.

5.3 with 6500 miles, single side exit, removed after 2 days

Vasa1 · January 28, 2020

Any pictures of this gm exhaust?

It's Tim · January 28, 2020

1 hour ago, mistaare said:

That's great feedback. in that two days did your DIC indicate any better mpg.

That is no where near enough data.

Texasdeere · January 28, 2020

Sorry I didn't pay close attention to the mileage. I couldn't imaging that it could lower the mileage in any way.

I will post some pictures of the exhaust when I get a break from work. It's going to be over a week from now.

I thought about trying a different muffler with the GM performance system but if it didn't work out it would be harder to re-sell, lose value and I would waste even more money.

I love to tinker with stuff and customize things but at 53 years old the noise just wasn't going to work for me. I really expected a factory offered set up to me more tame than this. I would imagine the younger crowd might like the sound just fine.

mistaare · January 28, 2020

59 minutes ago, It's Tim said:

That is no where near enough data.

Depends on how many miles he drove. I might have been a little OVERLY optimistic on that question.

mistaare · January 28, 2020

I read some people are getting a bump in mpg with cat back.

I would the bump in mpg with quiet-no highway drone exhaust. Don’t mind it louder ‘round town

just trying to confirm mpg claim

Amaze Productions · January 29, 2020

I purchased the GM Performance Exhaust upgrade for my 2019 GMC AT4 5.3. Its the Cat Back exhaust. I believe its similar to the Borla Touring Exhaust. However, I love it but wish it was a tad louder. Not going to complain though, because I did want more sound but nothing too annoying. Its been about 4 weeks and it has gotten louder. The tone is deep and sounds great. Overall Im happy with it. Hope this helps!

Also I get no drone on the highway.

mistaare · January 30, 2020

14 hours ago, Amaze Productions said:

I purchased the GM Performance Exhaust upgrade for my 2019 GMC AT4 5.3. Its the Cat Back exhaust. I believe its similar to the Borla Touring Exhaust. However, I love it but wish it was a tad louder. Not going to complain though, because I did want more sound but nothing too annoying. Its been about 4 weeks and it has gotten louder. The tone is deep and sounds great. Overall Im happy with it. Hope this helps!

Also I get no drone on the highway.

Any change in mpg

Amaze Productions · January 30, 2020

4 hours ago, mistaare said:

Any change in mpg

To be honest, if there has been a change in mpg, I haven't noticed.

mistaare · January 30, 2020

I know it's been said that with the CAI there is increased noise coming from the engine, but can anyone tell me how much louder the cabin noise is on the highway?