6.2L or Baby Duramax

djones208 · May 4, 2020

Hey all, looking for some opinions and input. I know it's been discussed but now that the 3.0 has been out a little longer I wanted to ask. I have a 2017 Z71 5.3l. It's leveled on 33-12.5 M/T. I don't tow often but plan on rowing some more in the and possibly picking up a smaller travel trailer. It does fine, but the tires definitely killed mpg, my mostly highway combined is usually 13-15. What are thoughts on 3.0l vs 6.2 in terms of both towing and mpg with larger load range E tires? I'm primarily looking at the 6.2L LT TB vs the RST Z71 3.0. From a visual standpoint I could go either way, I'd probably leave the TB alone for a while but level with wheels and tires right off the bat with the RST.

Anyone have real world mpg on either engine with 33s? Or towing with either? Ive owned a 2500 in the past but want to bridge the price gap until I actually buy something large enough to justify needing the towing capability of the 2500.

Thank you!

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BigDog88 · May 4, 2020

Ive never owned the 3.0 diesel. But i bought a brand new 6.2 Max Tow HC Silverado a month or so ago and have pulled my TT with it once through the hills of southern Missouri and back to KC last week. I got 8.9 mpg running 70 on cruise control. pulling the 31 ft TT that weights between 6,800-8,200 depending on how its loaded. Not great but it had plenty of power, noticeably more than my 5.3 had pulling same trailer on the same route. Im happy with it, but also because gas is cheap (even with using Premium fuel), so not a big deal. I personally also prefer the sound of a V8 over a small diesel. I have seen good towing reviews on the 3.0 and of course would give you alot better mileage when not towing.

newdude · May 4, 2020

If you find a 3.0 diesel with 20" wheels from the factory, the stock 20" tire they use is a 33 inch tire (275/60R20), non LT rated. Might still be a good rough measure on where fuel mileage would be. LT tires you are probably 5-10lbs more per tire.

How much trailer are you towing? Curb weight or GVWR of the trailer?

Edited May 4, 2020 by newdude

sweatandsteel · May 4, 2020

I was considering the same thing as we plan on purchasing a travel trailer in the next couple of years. I stuck with the 6.2 since I was used to it and know what to expect. A part of me wanted to try the 3.0 but didn't want to be in early if there are unknown issues that haven't popped up yet.

TRKLGND · May 4, 2020

Don't level it. Whichever truck you go with please don't level it if you are going to be towing. 700lb - 800lb of tongue weight plus whatever else you put in the bed will have the nose of your truck point 2" - 3" up in the air. Not only is that not good for steering and your front tire wear, it looks retarded.

Jav_eee · May 4, 2020

Don't level it. Whichever truck you go with please don't level it if you are going to be towing. 700lb - 800lb of tongue weight plus whatever else you put in the bed will have the nose of your truck point 2" - 3" up in the air. Not only is that not good for steering and your front tire wear, it looks retarded.

Looks are subjective. And besides, even stock height trucks can sag. Level it if you want but make damn sure you adjust your headlights afterwards.

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mike5511 · May 4, 2020

Having owned a diesel, I'd get the 6.2 gasser and wouldn't even hesitate.

pewterliftedz · May 4, 2020

It's a toss up, I've had 6.2s on my 2 previous trucks, and it's a great engine with power across the powerband (more so up top). Once I threw a set of 295/60r20 tires on it though, the power was sucked away compared to stock. The factory 3.23 gearing and 8 speed trans sucked for bigger tires, maybe the new A10 would be better. It towed great, but as with all LS engines, it needed to down shift and get the RPMs up to get going.

I now have the new 3.0, and the instant torque is great, but it lacks horsepower up top where the 6.2s used to shine. I've towed very little with the new truck, and it was only 3,000 lbs or so, but it felt like nothing was back there around town. I'm only running a Nitto Ridge Grappler 275/55r20 XL on my truck, since I wanted a light weight tire to maintain great highway mileage.

It really a toss up, but I bought the 3.0 so I could get great fuel mileage for my daily 90 mile commute. If you can find a RST with the "Diesel Off Road PAckage", you would be ready for bigger tires with the 3.73 gear ratio that is included. The 6.2 definitely gives you more smiles per gallon, but you fuel mileage will suffer with bigger E load tires.

Edited May 4, 2020 by pewterliftedz

TRKLGND · May 4, 2020

37 minutes ago, Jav_eee said:

Looks are subjective. And besides, even stock height trucks can sag. Level it if you want but make damn sure you adjust your headlights afterwards.

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If a stock truck sags 2" it is now level and the suspension works as designed with a load. If a leveled truck sags 2" the front end is 4" up from spec. Less weight on the front tires, less steering control and it looks horrible. Subjective, yes. Show me one person that truly likes that look.

Likarok · May 4, 2020

It sounds like the 2.8 Duramax in the Colorado's is going to be dropped when the Colorado / Canyon redesign happens next. And even the 3.6 V6 for that matter. Looking at a Turbo 4 cylinder.

steve841 · May 4, 2020

I owned a 19 with the 6.2L and now a 20 with the the 3L Duramax.

Here's the simple of it:

6.2L beast of an engine. Fast as hell. Sucks fuel. Did I mention it SUCKS FUEL? And likes premium on top of that.

3.0L Sweet smooth diesel and only sips fuel compared to the 6.2. Not obnoxiously loud. Only downside, DEF.

So, unless you're holeshotting every light. Racing other folks up the highway, the diesel is king. Tows pretty much the same amount and less visits to the gas station.

Jav_eee · May 4, 2020

3.0L Sweet smooth diesel and only sips fuel compared to the 6.2. Not obnoxiously loud. Only downside, DEF.

DEF, a limited life DPF and an EGR that’ll clog soon enough, and frequent fuel filter changes although they’re not as pricey as the bigger diesels...

Maybe I need a 3.0 instead of a 6.2...

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pewterliftedz · May 4, 2020

21 minutes ago, Jav_eee said:

DEF, a limited life DPF and an EGR that’ll clog soon enough, and frequent fuel filter changes although they’re not as pricey as the bigger diesels...

Maybe I need a 3.0 instead of a 6.2...

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Do you consider 30,000 mile fuel filter changes frequent? DPF and EGR are under warranty for 5 year/100,000 miles, so I've got plenty of worry free miles ahead.

Edited May 4, 2020 by pewterliftedz

Jav_eee · May 4, 2020

Do you consider 30,000 mile fuel filter changes frequent? DPF and EGR are under warranty for 5year/100,000 miles, so I've got plenty of worry free miles ahead.

I consider 30,000 miles to far in between and would never go that far. Used to do them every 12k on my f250. DPF and egr usually go at about 125k so fingers crossed!

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