And The Winner is... 2500HD 6.0L

[Cowpie]

All in all, it really doesn't matter. Whatever differences there are are negated by the differential ratios offered for each motor. With 4.10 rear ratio, the 6.0L is going to actually have at least as much power at the wheels as the 6.2L with the taller ratios. Both the 8 speed and the 6 speed have virtually the same top gear ratio in the trans. .65 for the 8 speed and .667 for the 6 speed. True, the steps are smaller in the 8 because of the two extra gears, and the bottom is a little lower. But factor in the 4.10, and differences start to disappear.

 

I have contended all along, that it is not just the motor specs that make a great puller, it is everything tied to it that makes it all come together. My little 12.7L Series 60 Detroit motor in my semi truck can walk the hills right along with 15L Detroits and Cummins motors all day long, and even walk away from them on occasion, when gross vehicle weights are the same. Doesn't make sense. Both of the bigger motors are putting out 200 or more extra pounds of torque than my 12.7. But it is the transmission and the rear ratios that make the difference.

 

And your comment about neither pulling the heaviest trailer at 2000 RPM is not quite a study in similarities. The pickups these different motors are in differentiate in weight quite a bit. And the capacity of the trailers they can pull varies as well. I would have no problem putting the 6.0L in my 2500 up against the 6.2L in the 1500, if both gross combination vehicle weights were the same. So feel free to load up a 6.2L 3.42 1500 to 17,700 lb gross (pickup and trailer), and I will hook up a trailer that sets me at 17,700 lb (pickup and trailer) with my 6.0L 4.10 2500 and we can see how they each do the job. I have seen no one in the truck rags or anywhere else even try to do this comparison. But I am pretty sure that the 1500 would not leave me in the dust. The 4.10 diffs make the difference, and more than offset the differences in engine torque. Torque output at the flywheel is one thing. Torque that actually is on the ground is another.

On another issue. I am out of town on business, so no, I will not post signs from gas stations. Some of us actually have productive things to do with our lives than running around taking pics of gas station fuel cost signs. Download the Gas Buddy app and check for yourself for Newton Iowa and towns around there, where I was basing my fuel cost numbers from. Since that original post, prices probably fluctuated a little. But the spreads are still substantial. Now Gas Buddy will not show E15 for any area. But it is clearly being sold in my area at a 10 cent per gallon lower cost than E10. It is advertised as such at Murphy's at the Walmart in Newton. They have a big bold banner stating that E15 will always be 10 cents per gallon lower than E10 regular, which by the way, is 20 cents lower than E0 regular.

 

Just checked the Gas Buddy. Premium at Casey's and Phillips 66 in Newton is 3.18 a gallon, posted 4 hours ago. Regular is 2.58 at Love's 1/2 hour ago. Love's is a truck stop outfit on the interstate, so they are usually several cents higher than Murphy's in town. But we will stick with the 2.58 for now. 3.18 minus 2.58 is a 60 cent spread. Now factor in the guaranteed 10 cent lower cost of E15, and that is a 70 cent spread. I dearly love it when folks think I am full of it.

[Cowpie]

I realize my mpg on the 2500 is suspect. And I will agree it is outside the norm. But then, over 5 million logged commercial driving miles has helped me develop techniques to get the most out of a vehicle. I average a solid 20% better fuel economy with my semi truck than the general freight OTR sector national average. That is 6.5 mpg. I dumped the ECM recently and it had a lifetime average of 7.83 over 400,000 miles. last month, everything worked out great to where the average was a solid 8.5 mpg, Considerably higher than the OTR sector average. And when you factor in that a simple 0.1 mpg increase, taken over the typical year, is roughly a $600-$800 dollar savings in fuel over the year, imagine how much more profit i obtain by getting the mpg's I do compared to the average truck operation.

 

To satisfy your curiosity on mpg with the 2500, here is a pic of the DIC on a road trip we took the week before Memorial Day. I hand calculated as well, and the difference was only .003 mpg. This has been typical of all road trips so far. Wife took the pickup to Missouri to a friend's wedding recently, and averaged 17 for the trip also. So it was not just me. Maybe she learned a thing or two on how to drive a vehicle over the years from me. And this was on that sorry 10% ethanol fuel that everyone has a fit over (only E15 I get is at home area, couldn't find it on the road). Might even get better mpg if I filled with non ethanol.

 

If folks aren't getting somewhat similar results, the fault probably lies with the person behind the steering wheel. After all, fleet studies have shown that the driver has a 33% average effect on fuel economy. But it is so much more satisfying to blame the equipment than ourselves.

 

[Jon A]

Just checked the Gas Buddy. Premium at Casey's and Phillips 66 in Newton is 3.18 a gallon, posted 4 hours ago. Regular is 2.58 at Love's 1/2 hour ago. Love's is a truck stop outfit on the interstate, so they are usually several cents higher than Murphy's in town. But we will stick with the 2.58 for now. 3.18 minus 2.58 is a 60 cent spread. Now factor in the guaranteed 10 cent lower cost of E15, and that is a 70 cent spread. I dearly love it when folks think I am full of it.

 

Seriously? Prices at two different locations? Why not go the extra mile and compare the price of regular in Saudi Arabia vs. the price of premium in France? That would make your math look really good!

 

Obviously, the only meaningful comparison is one at the same station at the same time. So next time you fill up, take two seconds, whip out your phone and take a pic of the pump. If it's anywhere near an 80 cent difference, then you will have proven yourself to not be full of it. Until then.... And you do realize you'll get lower mileage on E15 than you do on E10 right?

 

Whatever differences there are are negated by the differential ratios offered for each motor. With 4.10 rear ratio, the 6.0L is going to actually have at least as much power at the wheels as the 6.2L with the taller ratios. Both the 8 speed and the 6 speed have virtually the same top gear ratio in the trans. .65 for the 8 speed and .667 for the 6 speed. True, the steps are smaller in the 8 because of the two extra gears, and the bottom is a little lower. But factor in the 4.10, and differences start to disappear.

 

It doesn't work that way. If that was the case, an EcoDiesel owner could simply throw some 5.88's in the rear and it would pull stuff up hills just like the Cummins! Magic! Obviously that's not the case.

 

Torque output at the flywheel is one thing. Torque that actually is on the ground is another.

 

Exactly. Do you know what torque output at the ground at a given speed is? You may have heard of it. It's a term they call "Horsepower." Yes, I can derive all the equations to prove it but a simple example might do better.

 

At 65 MPH the 6.2 3.42 8-Speed, during a tough test like the Gauntlet is in 3rd gear at 5100 RPM. At this RPM the engine has 420 lb-ft of torque. That times 2.08 tranny ratio times 3.42 axle ratio = 2988 lb-ft at the wheel. 2988*12/15.4 tire rolling radius (655 rev/mile) = 2328 lbs of force at the pavement.

 

Your truck, 6.0, 4.10, 6-speed, will be in 3rd gear (you'd be over redline in 2nd) at 4300 RPM. At this RPM the engine has 380 lb-ft of torque. That times 1.53 times 4.1 axle ratio = 2384 lb-ft at the wheel. 2384 * 12/15.83 tire rolling radius (637 rev/mile) = 1807 lbs of force at the pavement. That's nearly 30% less force at the pavement.

 

In short, that means the 6.2 truck could maintain that speed up a hill with nearly 30% higher GCW than the 6.0 truck. That's HUGE. You may say that's not fair with how nicely the gears work out for the 6.2 truck--give the 6.0 some 4.56's, or give it the 8-speed, etc, and yes, you can make it come closer. But you can pound on your calculator until your fingers bleed and you can't make up for the lack of torque in the angry range of the RPM band (HP) with gears such that it wins any comparison. Sadly, gears aren't magic.

 

I would have no problem putting the 6.0L in my 2500 up against the 6.2L in the 1500, if both gross combination vehicle weights were the same. So feel free to load up a 6.2L 3.42 1500 to 17,700 lb gross (pickup and trailer), and I will hook up a trailer that sets me at 17,700 lb (pickup and trailer) with my 6.0L 4.10 2500 and we can see how they each do the job.

 

It's too bad you're so far away as I'd take that bet in a second. I'm not sure why you think you'd win? I know you're going to say it beat the 420 HP Hemi up the hill. It didn't. Stop deluding yourself. It beat about a 200 HP Hemi. For some reason that engine was in a reduced power mode. Beating that engine in that condition really isn't impressive at all. It does not all of the sudden mean HP and torque don't really matter, maybe some magic will save you. That's simply not what happened. The 6.2 will not lay down like that.

 

My setup is far from ideal, it would be much better all around with 4.10's and/or the 8-speed, but in the end that just means I'd be in 2nd gear instead of 3rd going up the hill. I'm pretty sure I could maintain 60-65 MPH up a pretty steep hill with that weight. I don't think you could.

 

If folks aren't getting somewhat similar results, the fault probably lies with the person behind the steering wheel. After all, fleet studies have shown that the driver has a 33% average effect on fuel economy. But it is so much more satisfying to blame the equipment than ourselves.

 

That is pretty impressive. Must have been the wife's doing! My wife always gets 1-2 MPG better than me.... Moderate speeds do wonders for your mileage. But I will contend, in the conditions in which you got that result you would have had 20+ at the minimum with a stock 6.2.

 

Edit: Looked at a chart crosseyed the first time. Got it fixed and corrected the numbers.

[Cowpie]

Well like I stated, out of town of business. Had to rely on numbers that had actually been recently posted on Gas Buddy. Small town, prices not spread around in a manner you imply. Childish.

 

Hey, not sorry a bit that I drive moderately. Great for business! Just turned over 426,000 miles on original set of drive tires on my semi truck and they don't need to be replaced yet. That I am getting 17-18 out of my 2500 and you choose to ridicule speaks more to your character.

 

Pretty sad way to debate. But message received. You don't like the facts. Gotta give you a hand though, you do indeed have a flair for the dramatic in you analogies.

[Cowpie]

I have to admit, driving down the road today, my curiosity has been piqued a little. What would a real world comparison of the 6.2L in the 1500 and the 6.0L look like in terms of MPG?

 

Of course, things would have to be about as equal as we could reasonably get. My 2500, full of fuel, people, cargo, etc for the road trip I posted the DIC picture for, weighed in at just over 7300 lb according to the scale at the grain elevator in town.

 

1) A 6.2L equipped 1500 would have to be loaded with whatever to get as close to the 7300 lb gross weight as possible.

 

2) Since the 2500 with 4.10 diffs and the 6L90 is turning about 1900 RPM at 65 mph, a 1500 would have to go to a lower gear to approximate the same RPM at the same road speed. Couldn't get it exact, but could be reasonably close.

 

3) For our purposes here, the trip should be a minimum of 300 miles. And it would have to include somewhat similar road situations like about 25% two lane, rolling hill, curvy roads. And it would have to include at least one stop off in a major downtown metro area. I had to make one business stop in downtown St. Louis along the river front during the day and all the associated daytime traffic.

 

4) reset the DIC and take off. Post a pic of the DIC at the end of the trip (on the 400 mile average screen). I am not going to quibble over if the DIC is as accurate as hand calculated mpg. Not going to be that petty.

 

I am sure there are others that would love to see the results. I sure would. I have no problem if the 1500 got 25-30 mpg! My intent here is purely academic. But we have been sparring over what one motor can do compared to another, but the applications have not been similar. Anyone who feels up to trying this unscientific real world test, please do and let us all know the results. I can't be the only one who would love to know what the results are!

[KARNUT]

Funny thread, I'll leave it up to GM, there is a reason the 6.2 isn't in the truck . It would save them a ton of money if they could use one engine for both. I can remember the 350 going in all the way up to a one ton dually, same with a 390, 460, 396 and 454.

 

 

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[Jon A]

Hey, not sorry a bit that I drive moderately. Great for business! Just turned over 426,000 miles on original set of drive tires on my semi truck and they don't need to be replaced yet. That I am getting 17-18 out of my 2500 and you choose to ridicule speaks more to your character.

 

There was zero ridicule in my post regarding your mileage. It was supposed to be a compliment! Don't let hurt feelings from losing an argument cause you to read into things stuff that isn't there.

 

 

You don't like the facts.

 

To the contrary, I have been all about facts. I'm giving you facts and numbers and will be happy to explain how they were derived and what they mean. I haven't seen any fact posted by you as the reason you think the 6.0 would win the contest against a much more powerful engine. It's hard to dislike what's not there.

[sahls01gmc]

I think I know how we can settle this. Both of you are driving the perfect vehicles for this comparison. Meet up and get a fully loaded trailer (+/- 17,000lbs) and lets see some competition! Or, get 2 identical trailers and do each comparison in live time! Drag race, MPG test, stopping distance, hill climb, hill descent, and every other data rich test and lets all see which one performs better!

[Jon A]

I have to admit, driving down the road today, my curiosity has been piqued a little. What would a real world comparison of the 6.2L in the 1500 and the 6.0L look like in terms of MPG? .....

 

I can't be the only one who would love to know what the results are!

 

That would be an interesting test, though tough to pull off in a scientific manor. But I'm the wrong guy to do it. I don't think I've ever gotten even 18 for a 400 mile average. Every time I go that far I'm going over big mountain passes at high speeds, not great for mileage. My 34" tires don't help either.

 

The best you can do is look for others who have driven the 6.2 in more ideal conditions. In this thread: http://www.gm-trucks.com/forums/topic/169188-best-2550400-mile-numbers/?hl=400there's one guy with a 400 average over 22, another with 24.

[sahls01gmc]

Nah, we can compare stats typed with a keyboard all day long. I want to see the real world test head to head. Not picking on you guys either, by the way. This would be a very important test because I bet there are a lot of people on here that are right on the fence of getting a maxed out 1/2 ton or throw down for the 3/4 ton.

 

Same trucks (that are being compared) with the same trailers going through the same tests at the same time. Then people can see the difference between the 2, where which one exceeds the other.

[KARNUT]

I think GM did and you have your answer.

 

 

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[sahls01gmc]

The 6.2 1/2 ton v the 6.0 3/4 ton?

[KARNUT]

The 6.2 in a 3/4 ton, sure would save money one engine for both.

 

 

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[sahls01gmc]

Aluminum vs Iron. That's the big difference there. There are positives and negatives about each one. That's even more reason I want to see the real world comparison between the 2 to see how each one performs!

[Jon A]

I think GM did and you have your answer.

 

The 6.2 in a 3/4 ton, sure would save money one engine for both.

 

You’re making a bunch of faulty assumptions.

 

First, there’s nothing “cheap” about re-tooling assembly lines. There is nothing cheap about redesigning the powertrains of an entire line of vehicles in order to use a different engine. The fact the engine itself may be a few dollars cheaper because it is used elsewhere is really small in the big picture. Virtually always, the “cheapest” thing to do in manufacturing is to never change the design.

 

Second, even if they do plan to spend the money and do the change, these things take time. Just because you don’t know of it happening within the first year or so of the engine being widely available doesn’t mean it’s not in the works.

 

Third, there are many reasons that have been listed in this thread why they may not want to do it which have absolutely nothing to do with losing a race up a hill. Premium gas requirement, LNG compatibility—feasibility, etc.

 

 

Nah, we can compare stats typed with a keyboard all day long. I want to see the real world test head to head. Not picking on you guys either, by the way. This would be a very important test because I bet there are a lot of people on here that are right on the fence of getting a maxed out 1/2 ton or throw down for the 3/4 ton.

 

Same trucks (that are being compared) with the same trailers going through the same tests at the same time. Then people can see the difference between the 2, where which one exceeds the other.

 

I agree, it would be great info. Unfortunately we’re separated by a couple thousand miles….

 

I expect this conversation to get even more attention in the coming years as Nissan comes out with the XD specifically targeted at the “fence sitters” which I do think is a pretty decent percentage of both markets. Hopefully that will inspire some of the magazines to do some comparisons combining the two categories instead of always separating them.