Does GM have it backwards?

[Bowti]

2019 Silverado 1500 offers a 6.2 with 420 HP and 460 lbs-ft of torque and 10 spd trans. The 2020 Silverado 2500 rumored to offer a 6.6 with 400 HP and 450 lbs-ft of torque and 6 spd trans. Shouldn't it be the other way around for these gas engines?

[APT]

It isn't a law. Durability has not been proven for the 3/4+ ton class yet.

[Bowti]

1320Fastback wrote:
The 1/2 ton won't have the equipment or design to support the duty cycle of the heavier class trucks.

It's like that cheap Hazard Fraught Mig welder for $80.00, sure it's much cheaper than a name brand welder but with a 20% duty cycle either you sit on your butt for 8 out of every 10 minuets or the thing overheats and shuts off.

OK, I get it, there is a law, that states a gas engine in a truck built for hauling and trailering more weight than a lesser truck can not have more torque or HP than the lesser truck. I get it now!

I am still looking for the law that states it can't have more speeds in the tranny than 6 speeds because it will just break.

[1320Fastback]

The 1/2 ton won't have the equipment or design to support the duty cycle of the heavier class trucks.

It's like that cheap Hazard Fraught Mig welder for $80.00, sure it's much cheaper than a name brand welder but with a 20% duty cycle either you sit on your butt for 8 out of every 10 minuets or the thing overheats and shuts off.

[ShinerBock]

N-Trouble wrote:
A tune may not degrade the life of the motor but you can bet it will degrade the transmission. Most tunes get rid of all the torque management nannies the factory program in.

Most tunes? How many tuning tables have you seen do this, because just about all of the ones I have seen retain torque management between shifts.

[N-Trouble]

A tune may not degrade the life of the motor but you can bet it will degrade the transmission. Most tunes get rid of all the torque management nannies the factory program in.

[DarthMuffin]

The 10sp trans is probably weaker than the 6sp trans and wouldn't support the towing rating people expect from a 3/4 ton.

[ShinerBock]

I believe there is a big misconception that if you tune the engine to higher than stock outputs that somehow you are shortening that engines longevity. This cannot be further from the truth in many cases today. Engines today are tuned to meet emissions and will even sacrifice the longevity of the engine to meet them.

Case in point are the diesels today. All of the emissions systems on these diesels actually decrease the longevity of the engine through fuel dilution and carbon buildup. Then there is the pilot injection which lowers NVH, but you are adding to amount of times that injector fires which increases wear over time.

Another example would be my old Ecoboost F150. The stock map knocked quit a bit and pulled timing to stay within emissions. The truck would also go into a limp mode if two misfires were detected in a single firing event. Why? Not to save the engine, but to save the catalytic converter from excess fuel. It would misfire because there was moisture buildup in early model intercoolers because the EPA no longer allowed manufacturers to add weep holes because it "could" leak contamination.

Altering the fuel maps and taking out these emissions perimeters in my Ecoboost decreased knock events allowing the engine to run more advance timing which increased power output. Now I will say that adding a lot of power to an engine will be hard on parts and decrease longevity. However, adding power by removing stock tuning that is designed to meet emissions will not necessarily equate to decreased engine life.

[spoon059]

Bowti wrote:
So the idea is to have less HP and Torque and fewer speeds in the tranny, with a engine with more cubes, in a truck designed to haul more payload and pull a heavier trailer, than a lesser truck, is a good thing? That sure isn't the reason I have a Duramax in my truck.

No, the idea is to have an engine that can create its rated HP/torque and pull it 8-10 hours a day for several days on end, for several years, and still be able to create that rated HP/torque.

The 6.2 with aluminum and high compression in the 1500 is a sporty little engine that can create lots of power for a little while, but isn't meant to create that kind of power all day every day. Meanwhile, the iron block of the 6.0 (and likely the iron block of the 6.6) will fare better in the long run.

People buying a 3/4 or 1 ton truck want and engine that will last for a long time and create consistent power for a long time. There is a trade off between power and longevity.

Your Duramax can get a tune and create much higher power numbers... but it won't last as long as the stock tune will. Again... there is a trade off between power and longevity.

[Bowti]

So the idea is to have less HP and Torque and fewer speeds in the tranny, with a engine with more cubes, in a truck designed to haul more payload and pull a heavier trailer, than a lesser truck, is a good thing? That sure isn't the reason I have a Duramax in my truck.
I guess I am still upset about how GM used to detune the old BBC and many of their other engines.
Maybe another tranny option would help, although I like the 6.6 concept.
Sorry just venting some frustration on this new design, maybe I will get used to the looks.

[ShinerBock]

Another thing, the 6.2L uses premium fuel and a high compression ratio to achieve those power numbers and I doubt the 6.6L does to attain that 400/450. That would not go to well with fleet buyers.

[mkirsch]

To what BenK says, the 6.2L is more of a "play" engine, where you mash the skinny pedal to the floor and it puts a smile on your face, while the 6.6L is a "work" engine, designed to run under heavy loads day in and day out.

If GM were confident that the 6.2L engine would hold up in a work truck, they would be putting it in the work trucks. As it is, they are depending on most customers only buying it for bragging rights, and never really using the engine that hard.

[carringb]

Another example: 3.5L Ford EcoBoost makes 365 HP in under 8500 GVW applications (F150, Taurus Explorer). Or more with the newer high-trim trucks. But the Transit, which most body configurations are over 8500, it's dialed back to 310 HP.

[Grit_dog]

6.4 Hemi in a car makes almost 100hp more than the truck engine too.

[ShinerBock]

Bowti wrote:
2019 Silverado 1500 offers a 6.2 with 420 HP and 460 lbs-ft of torque and 10 spd trans. The 2020 Silverado 2500 rumored to offer a 6.6 with 400 HP and 450 lbs-ft of torque and 6 spd trans. Shouldn't it be the other way around for these gas engines?

Class 2A(aka. half ton) trucks have different emission certifications and duty cycles of class 2B (3/4 ton) and up trucks. Same holds true for pick ups versus cab and chassis trucks. This is why the power ratings on class 2A trucks are generally higher than those of class 2b and above. Most people only think it is due to duty cycle, but that is a smaller part of it compared to emissions requirements.

Prime example is the Ford 6.2L engines. In the F150 it made 411 hp, but in the 3/4 and up trucks it was de-tuned to make 385 hp. Another example would be diesels. A 6.7L in a SD pickup makes 440 hp, but due to different emissions certifications the cab and chassis 6.7L makes only 330 hp.