Any real world experience? Looking at a `12, CC, SB, 4X4, with the 4.8 and 4 spd auto. I've had 5.3 in the past and was satisfied. Any real world noticeable difference? I had. `00 Tahoe with the 4L60E and had to have it rebuilt. Are the newer ones any more reliable?

Truck would be a DD and tow up to 3500# monthly and possibly 9500# twice a year. That would be it.

Any reason to pass on the 4.8 and hold out for a 5.3 in a similar truck based on this type of use?

Hillbilly this isn’t probably pertinent to your situation but my father in law had that motor and tranny and absolutely hated it....sluggish ......but it was an early 2000 model
5.3 is my vote

Have an 05 with 4.8 and it struggled badly to tow our 20’ camp trailer.

5.3 hands down.

Brother in law had a 2008 4.8 extended cab. I went on a trip with him and best mpg was 14.8. Constantly going from 4 cyl to 8 cyl. He did not keep that truck long. I now for a fact seen a 2019 5.3 with 3.42 gearing get 29.4 mpg on the highway and it is still recorded as his best mpg. Stay away fro the 4.8 at least the 2008 ones.

I have a 15 with the 5.3. It tows a 3800# camper but I'd hate to do it with a 4.8 L. Def not 9500#!

4.8 seems to look ok on paper but is a big let down if you dive one and then drive a 5.3. The 5.3 isn't exactly a suck you into your seat motor either. The 4.8 and 5.3 get roughly the same gas mileage soo...

You can buy a device called Range AFM disable that plugs into the ODB port and keeps the truck on 8 cylinders all the time. To me it's a must to have that.

I had a '05 4.8. It didn't really like to tow anything but I thought it was alright. Then I got a new Custom Trail Boss with the 5.3. I felt like I was driving a racecar. Never got the gas mileage I was lead to believe I would have gotten with the 4.8. I'd pass.

I figured these were the answers I'd get. Thanks for the confirmation. ☺

I've owned both in the same Chevy 1500, one was an 09 the other an 11. The 4.8 BLOWS. We have some decent hills here and if you put the pedal through the floor you were lucky to be doing 25MPH by the top. Logging trucks would pass me. MPG sucked too. I ditched it and got the 2011 with a 5.3, significantly better.

5.3 for sure.
I've got a 5.3 in my 2016 sierra crew cab slt and beat a kid in his Pontiac off the line at three separate stop lights. He had a girl in his car and we pulled up beside him at a stoplight. Had my two boys in car plus one of their friends.
I looked over at the kid in his Pontiac and gave him the thumbs up. He laughed and gave it back to me. I timed the light change and got on it and smoked him badly off the line to the next light. He pulled up beside me again and his girl next to him was laughing her (This word is unacceptable on Trapperman) off. I gave him the thumbs up again and beat him again at that light change.
At next intersection I could tell he was having fun but his girl was laughing so hard she was in tears. He rolled down the window and yelled at me 3rd time buddy? I saw light change in corner of my eye when I was looking at him and punched it again and beat him the third time. My boys and their friend by now are all into it too.
At fourth light it was an uphill and I looked over at him and he was all serious this time and his girl was still laughing so hard. I could tell this meant a bit to him not to lose to his girl. He got me on that one, my truck was too light in rear to grab pavement going up the hill and he had front wheel drive in that pontiac. I let him go ahead and save my tires for trapping.
5.3 will serve you much better my friend.
Jim

The 4.8L was there for the groups fuel consumption to satisfy the EPA. That's how GM does that.

How about they offer a 2.8L diesel in a 1/2 ton pickup! Are you kidding. The same engine for the Canyon/Colorado.

All to satisfy the EPA.

So order the 5.3. The 6.0 is strong, but doesn't pass a gas station.