Having trouble deciding on whether to get a 5.3 or 6.2. Looking in the 2014 to 2018 version of the GM / Chevy - mainly because of the adjustable pedals. I tow a 21' bass boat. I know they will both tow it but I like to set the cruise on 80 or so and just go - most of my trips average 5 - 7 hours towing the boat, and 75% of the miles I drive my truck are with the boat. The 6.2 recommends the premium fuel. I have had two older (2011) 6.2 and they were great but I did not get good fuel mileage with them. Never owned a 5.3 but a couple of buddies have and they seem to struggle up a hill with a head wind. I would like a diesel but I don't feel its practical for the increased cost towing no more weight than I do.

Thoughts?

I wouldn't touch anything that requires premium fuel.

They have never “required” diesel fuel. They just won’t make quite their rated peak power without it.

I’d look at a Toyota turbo 6 cylinder or a Ford ecoboost.

I used to get 18-19 mpg towing my bass boat when I had my Ram ecodiesel. It was amazing towing small loads. Might be worth consideration.

The 5.3 is mostly gutless. And the 6.2 requires a higher trim package than I was interested in back when I was looking at them.

The ecoboost isn't a bad option. But they're not fuel efficient if you're running 80 mph with a boat.

I have had 2 with the 5.3. I had a 2016 GMC Sierra All Terrain that was a very nice truck and pulled my 20' Skeeter well.....as long as you werent going uphill or trying to pass. Then after a drunk driver decided I didnt need that truck anymore I bought a 2017 model of the same truck. Of course the performance was the same. Got tired of the lagging nature while towing and started looking around. Buddy of mine had a 2500 with the 6.2 and was not happy with it. Said he still felt like he had to put his foot into it more than should be necessary. I was very patient in the process and finally found a 2018 GMC 2500HD 4x4 with the Duramax and Allison at a price I was happy with. Bought it with 41k miles on it. Took about 8 months of shopping around before I found the right deal but man was it worth it! This thing pulls like a dream! The Duramax has nearly double the torque of the 6.2 gasser. I have almost 75K on it now and have no plans of getting rid of it anytime soon. If you can hold off and find the right deal, you wont be disappointed.

Thanks for the input - now I have people telling me to consider the little duramax.

I have a 2021 Silverado Z71/RST with the 6.2 and 10 speed. Loving this truck so far. Running empty on the interstate, I regularly get 20+ mpg at 75. It has gotten as good as 25 with a slight tail wind. I usually run 89 octane in it but will use 91 if I know I'm going to be towing bigger loads. I frequently pull 24' or 26' box trailers for my daughter's high school band and it pulls those great as well and that's when I'll use 91 fuel.

Split the difference and go with a 6L.

+1

I had 09 5.3 Z71 and yes it was a turd pulling my ZX20. My V6 4Runner isn't much worse at highway speeds at towing. Taking off the 4Runner is actually better but it is harder to maintain speed but not as much as you would think. Won't be getting a 5.3 ever again if I can help it.

Same for me 89 unless I'm towing, great mileage for that size engine.

Tend to agree. I had an F-150 with the 4.6 that towed better than my Chevy with the 5.3

It's a gutless turd.

I’ve heard the 5.3 in those year models is pretty weak. A ford ecoboost is a good option in that year range. 3.55 or 3.73 rear end will cruise in 6th gear in most cases, might downshift to 5th on a fairly steep hill with that load. They make max torque in the 2500 rpm range so you cruise at max torque.