5.3 or 6.2 I have your answer. Read below

Joey Silverado Sierra Man · May 14, 2024

Are you trying to decide what to buy? 5.3, 6.2, HD? If you’re like me, you are reading everything the internet has to offer before you buy your next truck.

To give you my background, I have owned 3 Duramax 2500HD, 2 5.3 half tons, and now I own a 6.2 GMC AT4 2024. To describe my truck needs, I was comparing towing and fuel milage since ½ of my truck’s use is towing. I am an average guy who does a lot of off roading and fishing – hence towing my atv, jeep, or boat. I used to tow a skid steer with my past 2500 HD Durmax(s) but if you’re not hauling a huge camper, enclosed trailer, or something 9000LB or greater, you don’t need a ¾ or 1 ton.

When fuel prices went through the roof and diesels began to have emissions troubles, I decided to go back to the ½ tons. In 2022 I got back into a 5.3. The 5.3 is, in my opinion, the best motor an average truck driver would ever want. Both of my 5.3 (2008) and (2022) were the best engines I have ever owned. No problems, reliable, tow like there is no tomorrow, and with the DFM, the 2022 averaged 15MPG in the city and upper 22MPG on the highway (under 80MPH). Towing, my 5.3 got about 9MPG hauling a jeep on an 18’ flatbed (8K#) and about 11 hauling my 22’ boat (3K#). I live in Florida, so the land is flat, my biggest gas milage killer was traffic. The 5.3 was a 5 star motor and I would highly recommend it. I have 0 bad things to say about a 5.3. The 5.3 was also fast for a pickup truck.

I recently wanted a new truck with more bells and whistles. As I get older, the creature comforts are more important to me. Such as AC seats, power fold mirrors, 360 degree cameras, and all the new trailer options. I went to the dealer with the intent of buying another 5.3. However, the dealership had a 2024 GMC AT4 with the 6.2 marked down enough that I had to reconsider my engine option. I immediately went on the internet and began to read and watch YouTube videos. I liked what I saw with the 6.2 and decided to pull the trigger and buy the 6.2.

After having the 6.2 I must say that I love it. It is like a super sport or feels like a sport car of trucks. This thing is FAST. I could go on forever about how cool it is to drive such a peppy truck, but trust me, you will not be disappointed in the performance. Without a trailer, the truck gets about 15 city and 22 highway, just like my 5.3 did. I did not lose any fuel milage! If you drive like a grandpa, you can get a little better, but I have a heavy foot. If I really romp it around town, the fuel milage can drop down to 12ish MPG. Yesterday I towed my SxS 50 miles on my 18’ flat bed Big Tex trailer (about 4900#). Driving city and some backroad cruising, I got an average of 13.8MPG which I would have got about 11 in my 5.3. Having only had this 6.2 for a couple weeks, I cannot compare much more towing than that. However, my prediction was accurate that when towing, I can get a tiny bit better fuel milage with the 6.2 as it is not working as much and has more low end torque. But here’s the catch – the 6.2 must run on 91 octane or higher gas per the owner manual. So, mile per dollar, the 5.3 is probably a better choice. I am totally fine paying a little more for fuel to have a 6.2 that will “put you in the seat” when you punch the throttle. But, if you drive like you have sense, the 5.3 is “more fuel efficient.”

My overall conclusion: if you are totally focused on good fuel milage and a truck that will do the job, get the 5.3. You will not be disappointed. But, if you want to add a bit more power and fun, get that 6.2. Either way, you will be very happy. If you go to the dealer and test drive both, you will buy the 6.2 just like I did. Who in the world doesn’t want more power?

On a side note, I feel like this 6.2 gas ½ ton accelerates as well as my last Durmax (2015) even when towing. Obviously the ¾ ton holds weight better and has all the advantages of heavier duty running gear. Having owned both, for my needs, I’d choose the 6.2 and save $10-14K, unless I was constantly hauling over 9K#. Also, I hate towing a camper with a ½ ton and would only buy a HD if I was primarily towing a camper. For you camper towing guys, you’ll want airbags on any ½ ton you use to tow. Will my 6.2 tow that camper? heck ya; and so would have my 5.3. But you cannot beat an HD for those 25+’ campers and equipment hauling.

This is my experience and I hope it helps you decide.

Joey Silverado Sierra Man · May 27, 2024

Just towed the same sxs and trailer about 150 miles. 3/4 of the time was highway. At 70mph I got about 11mpg. 75 I got 9.6. At 80-85 I got about 7-8 mpg. I ran each of these on cruise control and flat ground. Honestly, I feel like the 6.2 should have got better mpg on the highway. But who really tows at above 75 on a highway? Not me, usually. The sxs does catch air and have wind drag. But… plenty of power and preformed like a diesel when passing and hitting the throttle. Over all- impressed with performance. Wish fuel mileage was just a bit better, but that’s the trade off.

Edited May 27, 2024 by Joey Silverado Sierra Man

KARNUT · May 27, 2024

1 hour ago, Joey Silverado Sierra Man said:

Just towed the same sxs and trailer about 150 miles. 3/4 of the time was highway. At 70mph I got about 11mpg. 75 I got 9.6. At 80-85 I got about 7-8 mpg. I ran each of these on cruise control and flat ground. Honestly, I feel like the 6.2 should have got better mpg on the highway. But who really tows at above 75 on a highway? Not me, usually. The sxs does catch air and have wind drag. But… plenty of power and preformed like a diesel when passing and hitting the throttle. Over all- impressed with performance. Wish fuel mileage was just a bit better, but that’s the trade off.

Considering my last new GM was in 2014. The only wrench I would throw in the mix is the E-85 option if it’s still an available option on the 5.3. You would have the best option for power on E-85 for trips you have the reg fuel option. If it’s not available anymore shame on GM. With the towing package I had on my Texas Edition GMC and when using E-85 it would rip. I would still be driving it if not for cylinder deactivation.

repairman54 · May 28, 2024

My last 5.3 was in my '11 Tahoe. Traded it in for my '23 6.2 Silverado. 6.2 blows away the 5.3, both power and fuel economy wise. I had zero drivetrain issues with the Tahoe in 150k also. I ran the Range DFM eliminator in it.

Towing the same boats and cargo trailers mileage was the same, 11 mpg in both of them on the same routes.

6.2's power is worth the premium fuel price. I alternate half tank fills between 93 and 89 octane gas to cut costs a little. No 91 in my area.

KARNUT · May 28, 2024

4 minutes ago, repairman54 said:

My last 5.3 was in my '11 Tahoe. Traded it in for my '23 6.2 Silverado. 6.2 blows away the 5.3, both power and fuel economy wise. I had zero drivetrain issues with the Tahoe in 150k also. I ran the Range DFM eliminator in it.

Towing the same boats and cargo trailers mileage was the same, 11 mpg in both of them on the same routes.

6.2's power is worth the premium fuel price. I alternate half tank fills between 93 and 89 octane gas to cut costs a little. No 91 in my area.

That true especially with the 11 5.3. In 2014 there was an improvement in the HP with the 5.3. It’s also tuned for regular gas. Where the 6.2 is tuned for premium gas. GM mostly over came the difference for awhile with the E-85 option on the 5.3. Then there’s the order sheet with options such as a towing package. Gearing can close the gap and help with towing fuel mileage.