And The Winner is... 2500HD 6.0L

Jon A · June 7, 2015

Well, I would say collapsing lifters via control solenoids that shut off oil to the lifters selected as the AFM does is a tad more complex that the stock hydraulic lifters of the 6.0L. ...

And as I said, for HD's they would likely delete this system--in which case the 6.2 would have the same old lifters as the 6.0...

And there is the DI of the 6.2L, while neat, can also increase the probability of fuel dilution in the oil.

It seems to be a bigger worry with turbo DI gas engines--that can't run as lean under load. Until oil analysis reports start coming back from these engines showing an issue exists, I wouldn't loose any sleep over it.

Good dig, and even I got a chuckle, but just a little arrogant and not a clear perception of terrain in Iowa isn't it? Next time you are out my way,...

It was a bit tongue and cheek, but clearly there's a lot of truth in it. I can't drive two hours down the freeway from our ranch without hitting a pass where the "Truck Speed Limit" is 35mph it's so steep--even in good weather! That's on the freeway--on back roads things can be much worse. Here's a pic coming down from one of our elk hunting spots in the Big Horns:

We usually were towing a goosneck with 5 horses, two wall tents, food, water and gear for 10 days of winter camping..... That's not a road you want to try and fly up at 70 MPH, but you also don't want to be in first gear at 15 MPH encouraging cars and other tow rigs to pass you when it's not safe.

Cowpie · June 7, 2015

Interesting, but I am not unaware of such things. I lived in central Alaska and drove commercially there for 10 years. But as to whether I would trust GM to do things right with a 6.2 in the 2500, I am not as confident as you. I doubt anyone can sway me away from the setup I have now. I hate being a guinea pig for an OEM. I like to stick with things that have long, proven track records. The L96 6.0 tied to the 6L90 offers that.

No interest in playing with the new emission diesels. I would only consider a diesel pickup if I could do it like my 2013 semi truck.... New truck with a factory rebuilt pre-emission motor. Since that is not an option, I pass.

Jon A · June 8, 2015

Nobody is trying to say you aren't aware such things exist. I was trying to illustrate to you why virtually nobody in certain parts of the country who actually need an HD have bothered buying a gas one over the last 20 years. I highly doubt the average corn farmer in Iowa has to deal with similar elevation changes on a daily basis.

And don't get me wrong, as much as I like the 6.2 and think it could get the job done for a lot of people, for a lot of others it wouldn't. It's a strong engine, but it's not a Duramax. The heavy daily towers still need the big diesel.

Cowpie · June 11, 2015

Granted. But the 6.2L is not a 6.0L either. We are purely speculating anyway, as there is no testing showing the 6.2L doing 20,500 GCWR up the Ike Gauntlet as the 6.0L has done. We only have the Ram 6.4L, which is virtually equivalent in power to the GM 6.2L Ecotec, and that got blown away on the Ike Gauntlet by the 6.0L in the 2500HD, which by the way, was loaded 300 lb heavier than the Ram 2500 it was up against. The 6.2L Ecotec does not have a long enough track record to confirm that it is a durable, long life, low repair motor either, as the 6.0L has a stellar track record for longevity and reliability. Numbers on a sheet can be impressive, but how it plays out in the real world is quite something else.

And I am on the record as saying that those who tow heavy frequently, can fully justify the Dmax. I am also quite aware that many will get it purely as a social statement as opposed to actually needing it. Like it is some sort of testosterone boosting thing by owning a diesel. You can see that when people put diesel logos on the back windows and such. People can spend their money on whatever they like, but I have been around long enough and have racked up over 5 million documented miles operating commercial diesels, that I am not fooled by rhetoric. The 6.0L is more than up to the challenge of a majority of pickup owners. And that is well proven by the numbers of 6.0L equipped pickups that are used commercially compared to the number of Dmax equipped ones. I have only anecdotal numbers, and GM is not very forthcoming with sales numbers, and from a commercial pickup standpoint, the numbers of gas equipped 2500 and 3500 pickups dwarfs the number of Dmax equipped ones. So it must be adequate for most other people's needs as well, as most folks are not crawling mountains day in and day out.

This whole argument is similar to what goes on in commercial trucking. That motor size makes the difference. I, daily, waltz past 15L Cummins ISX equipped semi truck on hills towing gross with my little 12.7L Detroit. And I regularly average close to 8 mpg doing it, which would be equivalent to a 6.6L Dmax getting 25 mpg all day long towing. How things are set up speaks more to how it plays out on the ground than size and numbers.

Jon A · June 11, 2015

Granted. But the 6.2L is not a 6.0L either.

You’re right, it’s not. It’s much more powerful and much more efficient.

We are purely speculating anyway, as there is no testing showing the 6.2L doing 20,500 GCWR up the Ike Gauntlet as the 6.0L has done. We only have the Ram 6.4L, which is virtually equivalent in power to the GM 6.2L Ecotec, and that got blown away on the Ike Gauntlet by the 6.0L in the 2500HD, which by the way, was loaded 300 lb heavier than the Ram 2500 it was up against.

Wow, now you’re trying to plaster the 6.2 with the sad, pathetic performance of Ram’s 6.4? Based on what? The 6.2 does not have a reduced power mode it will go into during a long tow as we saw with the 6.4. I’ve looked deep into the 6.2’s programming—it’s just not there. It’s like saying you think Tom Brady will have a bad year next year because he and Jay Cutler are similar players and Jay Cutler sucks. There is no technical relation. Saying the same thing might happen is nothing but pure fanboyism. We have seen multiple tests where the 6.2 is held at WOT for extended periods of time—it just keeps pulling strongly as long as you want.

Numbers on a sheet can be impressive, but how it plays out in the real world is quite something else.

This is getting ridiculous. There is simply zero technical reasoning for you to make these statements. There is no rational reason to expect the 6.0 could even come close to keeping up with the 6.2 when towing the same weight.

If one was turbo and the other wasn’t, you might make a case that the sea-level dynos don’t reflect how they’ll perform at altitude…. But that’s not the case. The engines are tested to the same SAE standards and environmental factors will affect them both equally on a percentage basis.

The 6.0 is 60 HP and 80 lb-ft behind. Not just at high RPM where it might not be all that useful, but even at just 2000 RPM the 6.2 has a 50 lb-ft of torque advantage. It’s not even close. There is no technical reasoning, no rational reason to believe the 6.0 could come close to keeping up—much less beating the 6.2 towing the same weight up a hill. Saying so can be based upon nothing but pure fanboyism.

Cowpie · June 12, 2015

We will just agree to disagree for various reasons. You obviously like the 6.2L Ecotec, and I am not convinced it is worth spending money on. All is moot anyway, as the 6.2L is not offered in the 2500HD, and that is the pickup I want as opposed to a 1/2 ton. Not for some serious towing so much as for hauling and other reasons. Towing was not my first or even second consideration for getting the 2500. I will admit, that having a non AFM motor with a strong track record was one of those considerations. So the 6.2L was not an option for me on 3 levels.

When we really get down to it, I am not a fan of any small block that GM puts out. I have always liked the 454 as a pickup motor. And I have no real need or desire to go diesel in a pickup, even more so with the emissions stuff on diesels nowadays. I already deal with the use of over 20,000 gallons of diesel a year for my other stuff. But since the big blocks are not offered anymore (and no, I never was fond of the 8.1L either), I have to settle for a small block, as I also have to "settle" for some other factors of pickup design nowadays. Even buying a pickup today is not a pleasure but a chore for me. Matter of fact, that is true about any vehicle, car or pickup. Nothing being made today really turns my head and motives me to buy one, so everything is purely on a practical level. To that end, I don't succumb to the "wow" factor. So longevity, reliability, etc play a more important role. For what is available, the 6.0L has the track record to meet that.

I have also studied the dyno charts on both the 6.0L and the 6.2L. The 6.0L reaches 90% of available torque at 2000 RPM and the 6.2L only reaches 75%, maybe 80% at best, of available torque at 2000 RPM. The 6.0L torque curve is a little flatter thru the RPM band. No, the 6.2L at 2000 RPM is not 50 lb torque ahead of the 6.0L at 2000 RPM, but more like about 25-30 lb, to be optimistic. Your contention that the 6.2L has 50 lb more torque at 2000 RPM is fallacious. The curves are not comparable across the RPM band. But it still remains, how a motor uses the available torque efficiently is still a factor. Overall design comes into play from the intake to the tip of the exhaust. If I have learned anything from putting together commercial semi truck specs, I have learned that. Heavy truck diesels that have only 1650 lb torque can walk all over other trucks that have 1850 lb torque motors all day long if they are spec'd properly throughout. There is a lot more that goes into making a motor effective than what it does on the dyno.

Jon A · June 12, 2015

I have also studied the dyno charts on both the 6.0L and the 6.2L. The 6.0L reaches 90% of available torque....

90% of much less, is much less.

No, the 6.2L at 2000 RPM is not 50 lb torque ahead of the 6.0L at 2000 RPM, but more like about 25-30 lb, to be optimistic. Your contention that the 6.2L has 50 lb more torque at 2000 RPM is fallacious.

You can have your own opinions, but not your own facts. More closely studying the official sheets ( http://gmpowertrain.com/2014_images/charts_lg/2015_60L_L96_SierraHD_10M.jpg http://gmpowertrain.com/2014_images/charts_lg/2015_L86_6_2_V8silSie.jpg ) and using a caliper to interpolate, I come up with 381 lb-ft for the 6.2 at 2000 RPM and 337 for the 6.0.

That's a difference of 44 lb-ft. No, not quite the 50 it looked like at first glance, but if you're only seeing 25-30 you need to have your eyes examined.

But it still remains, how a motor uses the available torque efficiently is still a factor. Overall design comes into play from the intake to the tip of the exhaust.

This is just meaningless mumbo-jumbo. We aren't comparing drastically different engines where different dyno techniques are required to get an idea how they'll do on the road under load.... They're both N/A gas engines virtually the same size. When one shows a 44-80 lb-ft advantage throughout the entire RPM range, pretending there may be some way the other engine wins any sort of contest is akin to saying 2 + 2 = 5 because that's the answer you like better. Irrational fanboyism in the face of contradicting facts.

Cowpie · June 13, 2015

Couldn't get your link to work. Here is what I used. Granted my eyes aren't calibrated, but from what I see, the 6.2 is, at best, roughly 375 lb torque at 2000 RPM. The 6.0 is roughly 350. Calculating it at 90% for max, would put it around 342. Still the 25-30 lb difference I mentioned.

Cowpie · July 1, 2015

One thing that got overlooked in the discussion... fuel. Followng GM advise, one is stuck only using premium in the 6.2L Ecotec3. While in my 6.0L, I get to use E10, E15, E20, E30, E85, regular or premium. Did a little number crunching on mpg's and cost for fuels. I get around 18 for highway mileage on E15 regular 88 octane at around $2.40 in my area. Premium in my area is around $3.20. For it to be just a break even on cost per mile, I would have to get a minimum of 23 mpg highway all the time with the 6.2L. That is just to break even on a cost per mile basis. And by having a motor that can fill with just about anything but diesel and kerosene, I have a broad selection of fuel choices that meet my needs and can shop of what gives me the best value on a cost per mile basis. I would be willing to bet that was part of the reasoning why GM decided to leave out the 6.2L from the 2500/3500 series pickups. Since commercial users are the primary buyers of the HD pickups, they are not interested in being tied to premium as their only option.

becker87 · July 1, 2015

I would be willing to bet that if they did decide to put the 6.2 in the HD trucks they would tune it to run on more than just premium. But then it wouldn't be the same HP but I would bet it would still best the 6.0 in power output.

Cowpie · July 2, 2015

I had read somewhere, and for the life of me I can't remember where or I would link to it, that there is a 6.2L version of the Ecotec3 that is dropped from 11.5 to 1 on compression to 11 to 1 to allow lower octane fuels to be used along with possibility of flex fuel. Maybe that is just in R&D and not ready for prime time yet. I have no clue. Darn, I wish I could find where I read that. I don't recall seeing what, if any, changes there were to power output, but I would guess that it would be a little lower than the output of the 11.5 to 1 L86.

BlackZ71Silverado · July 5, 2015

Interesting. Should make people stop complaining about the 6.0 being underpowered compared to Ford and Ram.

I agree......For some reason people seem to talk negatively when it comes to the 6.0L GM uses in the 2500HD gasser and I never understood why. It is a proven powerplant and has stood the test of time. It's a very strong engine and the tests done by TFLTruck prove that.

There will still be those people talking about the 6.0L and how it's outdated and isn't powerful enough to be in an HD. Funny thing about that is it is usually people who have never owned one themselves or even driven one for that matter. Nice to finally see all of the HD gassers lined up and tested against each other.

becker87 · July 6, 2015

I had read somewhere, and for the life of me I can't remember where or I would link to it, that there is a 6.2L version of the Ecotec3 that is dropped from 11.5 to 1 on compression to 11 to 1 to allow lower octane fuels to be used along with possibility of flex fuel. Maybe that is just in R&D and not ready for prime time yet. I have no clue. Darn, I wish I could find where I read that. I don't recall seeing what, if any, changes there were to power output, but I would guess that it would be a little lower than the output of the 11.5 to 1 L86.

The old 6.2s, like the one in my truck can use E-85 unlike the new ones, also doesn't have AFM. Wonder if it was a version of the old one.

Jon A · July 14, 2015

Couldn't get your link to work. Here is what I used. Granted my eyes aren't calibrated, but from what I see, the 6.2 is, at best, roughly 375 lb torque at 2000 RPM. The 6.0 is roughly 350. Calculating it at 90% for max, would put it around 342. Still the 25-30 lb difference I mentioned.

OK, maybe you need some help reading a chart. 1/2 way between 350 and 400 is 375, right? With your bare eyeball you can clearly see the 6.2 is well above 1/2 way between the two values at 2000 RPM. Actually measure it like I did and you'll get very close to the 381 I did. 1/2 way between 300 and 400 is 350. The 6.0 is significantly below 1/2 way between those values, only a little better than 1/3 of the way up (which would be 333)--thus my estimate of 337. That's a difference of 44 lb-ft. One may be able to quibble over 2-3 lb-ft on each measurement, but the only way you could come up with 25 is if you're looking at the charts crosseyed.

As neither engine is going to pull the heaviest trailer up the steepest hill at 2000 RPM, it is a bit moot though. I know you want to pretend the differences at higher RPM don't matter, but they do. When you're towing with a gas engine, it's going to run a gear or two lower when the load is high, that's just the way it is. That's what they do best.

The other day I was pulling a trailer up a pass and it did downshift into 3rd, pulling it up at about 3500 RPM. The difference there is about 55 lb-ft. The 6.0 with the same gearing may have needed to downshift another gear. With 4.10's and stock tires, the engines would have been at 4500 RPM in 3rd...where the advantage is 75 lb-ft....or 3400 in 4th where the advantage is 50+ lb-ft.

While the torque at 2000 RPM is of some interest for drivability and how the engine can pull moderate loads up slight grades without downshifting, it isn't that meaningful for heavy towing up big hills. While, as stated, the 6.2 does have a significant advantage at 2000 RPM, in the RPM ranges used by these engines when doing heavier towing, the advantage of the 6.2 just gets bigger and bigger.

Jon A · July 14, 2015

One thing that got overlooked in the discussion... fuel.

Actually, I mentioned it two months ago in this very thread (post #22), but thanks for noticing.

E15 regular 88 octane at around $2.40 in my area. Premium in my area is around $3.20.

As usual, the numbers you're using are a bit suspect. Could you please post a pic of the gas station sign? Or one of the pump that shows Premium being $0.80 more expensive per gallon? Typically premium is $0.20-$0.30 more than regular. Doubling or tripling or quadrupling the difference sure makes your math look better though.

I get around 18 for highway mileage

And yet in threads like this: http://www.gm-trucks.com/forums/topic/170166-fuel-mpg-in-the-60-engine/ Where dozens and dozens of people are reporting their mileage, nobody (not even you) seem to be getting a solid 18 on the highway. In fact, many seem to be questioning the 16 mpg number you gave as a bit above the norm.