Most reliable platform/engine/transmission combination

Kableguy · August 25, 2023

In the market for a new truck. My primary decision point is long term reliability and total cost of ownership. Thinking 20 years/ 300,000 miles is the goal. Ride is not a factor, mpg is not a factor. Anything I would tow could be handled by a 1500, but a 2500 would be ok and maybe give more flexibility if I have a need in the future.

Would a 2500 with the Duramax be much better than any of the 1500 offerings? I’m just not sure what’s the best way to go for long term reliability. Thanks.

newdude · August 25, 2023

1 hour ago, Kableguy said:

In the market for a new truck. My primary decision point is long term reliability and total cost of ownership. Thinking 20 years/ 300,000 miles is the goal. Ride is not a factor, mpg is not a factor. Anything I would tow could be handled by a 1500, but a 2500 would be ok and maybe give more flexibility if I have a need in the future.

Would a 2500 with the Duramax be much better than any of the 1500 offerings? I’m just not sure what’s the best way to go for long term reliability. Thanks.

If buying new, 2500HD with the 6.6 gas and 10 speed. Which is the same as me saying 6.0 gas with the 6 speed on the older trucks. Keep the oil changed, fluids changed, they will just about not stop running. No AFM/DFM either. Downside? 14mpg empty, 9-10mpg towing.

Diesel is great if you want to yank a big loaded trailer from 0-60 in like 7 seconds. But the newest diesels are quite temperamental with all of the emissions equipment and sensors attached to them. Fuel costs more, DEF is added expense, oil changes run higher. Also, fuel system is mucho $$$$ when (not if) it fails.

Edited August 25, 2023 by newdude

Gangly · August 25, 2023

Older GMs with the 6.0 LQ4's and LQ9's mated to a 6 speed transmission. With proper maintenance, they are bulletproof.

New diesels will go just as long as older diesels, but the cost of ownership until the engine is no longer useable/repairable is extreme compared to older diesels, and its almost entirely emissions related issues. If you could remove the EGR and DEF systems, the engines would go for ever. However, the soot buildup from the EGR system, combined with the moisture created from the condensing processes occurring in the intake track, creates significant soot deposits in the intake track which initiates and propagates corrosion.

If you go with a modern diesel, I would strongly suggest an oil sample analysis every oil change to look for sulfides and the presence of aluminum oxides.

64BAwagon · August 25, 2023

Aside from all the Duramax owners who had to replace head gaskets.

Kableguy · August 26, 2023

It sounds like since I don’t really have a need for the 6.6 Duramax it doesn’t get me anything special. I’m guessing the 3.0 Duramax falls in the same category, although the mpg is tempting. The 6.2 in a 1500 for the hot rod feel is tempting. Don’t want the small turbo, and the 5.3 doesn’t seem too exciting. The 6.6 gasser sounds pretty reliable. I guess I have a lot of research to do.

64BAwagon · August 26, 2023

If I were to buy a new 1/2 ton GM truck I would opt for the 3.0 diesel and pay up for an extended service plan if I planned to keep it beyond the new truck warranty. I think it offers the best mix of value, reliability and mileage of all the other choices. My biggest beef with it is the DEF.

I will never own another 6.6 Duramax or any of the other light duty diesel. Its too big of a crapshoot for emissions and reliability problems.

Edited August 26, 2023 by 64BAwagon

Dennis Hayes · August 26, 2023

I've had three 6.2 gas engines and the first one back in 08 had a rear main leak at about 80K. Other than that all three have been bullet proof. On my 2023 Silverado i'm getting 16/21 mpg and even more power than the first two. My wife didn't get that good of gas mileage on her 18 Tahoe with a 5.3. I believe this is the best overall combination in the gas class.

repairman54 · August 27, 2023

2x My 6.2 is 2-3 mpg better than my old '11 5.3 Tahoe and power wise no comparison.

No emissions diesels for me, I'm not trading trucks every 2-3 years.

4banger · August 31, 2023

since the 2.7t in half ton is one of only 2 engines gm engineers couldn't kill, that they added power after 3 years without issues, now 2 years later they are giving it the same warranty as the 3.0 diesel, and it's build like the diesel and runs lower cylinder pressures, and is much simpler without emissions systems at all, and less parts overall (less cylinders/turbos)...if a guy had to bet right now with all evidence on hand for the half ton market across the big 3 or big 5 etc.....the 2.7t is the most gen1 cummins like in choices and most likely to be a high mileage champ, sounds like the techs work on it the least in the shops etc. haven't heard of a common warranty issue for these yet, they don't have lifters, starting to see more threads and discussions about 10 Spd troubles now but none on the 8 spds, so looks like a winner, yes I'm aware the early 8 spds were jerky shifters but didn't hear much them actually failing, just annoyed people with a clunky cold 1-2 etc.

all things seem to point to the 2.7t gm as the lowest total cost of ownership and headaches in all of half ton land at the moment

Edited September 6, 2023 by 4banger

newdude · August 31, 2023

On 8/26/2023 at 9:12 AM, Kableguy said:

It sounds like since I don’t really have a need for the 6.6 Duramax it doesn’t get me anything special. I’m guessing the 3.0 Duramax falls in the same category, although the mpg is tempting. The 6.2 in a 1500 for the hot rod feel is tempting. Don’t want the small turbo, and the 5.3 doesn’t seem too exciting. The 6.6 gasser sounds pretty reliable. I guess I have a lot of research to do.

The 2.7 in HO/Turbomax form is a snooty little engine. I have one, and I love it. And so far the real world reliability of them has been quite good, good enough that GM upped the warranty to 5yr/100k like 4banger mentioned. Its built like the 3.0 Duramax (which both engines are on the CSS engine family) aka very diesel like. Forged internals, heavy duty pistons and rings to handle the boost, etc. But some long term considerations would be its got an electric water pump, and the cooling system is controlled by an electronic water control valve assembly.

I guess coming back to my first reply, I went with 6.6 because its the least complex of the engines available at the moment. Its got DI and VVT (they all do) but doesn't have AFM/DFM so should be no worry that it could lose a lifter. In theory, could GM hop up the tune in it to squeeze some more HP out of it? I suppose so, but that's not the point of the 6.6. Think of it just like the old LQ4 engines or the 4.6 SOHC modular Ford engines in the Crown Vics and Town Cars or the L5D in the 4500/5500 Chevy big trucks in where they are purposely tuned a bit lower for long life durability.

4banger · September 6, 2023

have heard good things about the 6.6 in the heavy duties also, it would be my pick if I needed the big boys, or just wasn't quite sure if the 2.7 is all that and a bag of chips yet, but it sure looks like it 5 years in and all evidence and information available so far, one should prove a lot easier on the wallet for a daily, the other might be best suited as the '2nd' vehicle that only gets used when work is required