Towing with 6.0 Engine? Or Do I Really Need A Diesel?

Cowpie · July 17, 2015

The Ecoboost with the 3.55 rear will out pull the Vortec with 4.10s.

Pulling power is only part of the equation, 3/4 ton will be much better planted, brake and handle better than the half ton.

If I were in your shoes I would seriously consider a DRW 1 ton. Yeah they suck for every day driving, but when your towing that extra set of wheels in the back makes a world of difference, especially in cross winds or dealing with turbulent air off of 18 wheelers.

Maybe in terms of speed down the highway, but you have to look at several variables. Like the individual gear ratios in the transmission combined with the diff ratio. There is solid reasoning why the 2015 2500HD 6.0L won the Golden Hitch Award for how it did, grossing a combination weight of 20,500 lb. Now that weight there would kill a F-150 quickly. Torque at the flywheel is one thing. Torque actually making it to the ground is another.

Folks look only at OEM charts and such and see impressive numbers and automatically assume that one engine will pull better than another. The real world is something else. This is not an apples to apples comparison, but the analogy is viable. I have a 12.7L Series 60 Detroit in my semi truck. 500 HP and 1650 lb torque. With similar loads and gross combination weights, I am pulling right with Detroit DD15's and Cummins ISX's (both 15L motors) that are putting down a similar 500 HP, but have 1850 or higher torque ratings. It is all in how the motor sweet spot for maximum efficiency is matched thru the trans and diff ratios that determine how well it will perform. And while my old factory rebuilt model year 2000 Series 60 is staying with or beating these newer motors with their higher torque, I am also getting roughly 20% better fuel economy with it than the general freight OTR trucking sector national averages. In real estate it is all about location, location, location. In towing, it is all about spec'ing, spec'ing, spec'ing. With a close to ideal combination, you can almost move mountains.

just because the L96 6.0L is not cutting edge anymore, does not mean it won't still hold it's own with many of the new kids on the block. it is a very reliable, long lasting, cost effective motor. There are thousands of these that have seen severe service with fleets and gone above 300,000 miles without a major problem. And GM did a pretty good job with it. The exhaust system is darn near perfect, except for the trash can muffler. Great intake and exhaust flow. And the 6L90 combined with 4.10 is a good match up for the motor. Even the Dmax equipped 2500 on the same Ike Gauntlet test bested the 6.0L by only 2.5 minutes. That either says the Dmax is not up to par or the 6.0L is no slouch ( I opt for that latter ). And the 6.0L beat the Ram 6.4 2500 by 1.5 minutes on the test.

Now, diesel is averaging equal to or lower than gas right now. The edge goes to the diesel. But that is not going to last forever. I go thru over 20,000 gallons of diesel a year in my business, and I clearly remember when diesel was well over $1 higher than gas and broke the $5 a gallon threshold. Don't think it can't happen again. Right now, the diesel folks have a distinct advantage. But there is the emissions game with diesels to also consider. As Scotty said one time in a Star Trek movie, "the more complicated you make the plumbing, the easier it is to stop up the drain". And boy, these new diesels are in a league of their own when it comes to complexity regarding the emission junk on them. When it works, it works great. When it falters, it can be a real nightmare. Warranty can take of most of that for a while, but once warranty is over, you might want to consider having some real cash in store if a DPF or SCR unit goes south on one of these. And even under warranty, you can automatically factor in multiple of time longer before pickup is repaired compared to a 6.0L.

Sure, you can remove the emissions junk, but you already laid out thousands more for the diesel, now you are going to shell out a sizable sum to remove the emissions junk, and you just then blew your warranty to pieces. You are totally on your own. And, depending on where you live, if some government hack wanted to make an example of you, the fines can be real harsh.

Tough call. Go with your gut. There are good arguments for both positions. Just go into any decision with eyes wide open. Don't buy into the latest fad or get something just to make a social statement. Use that gray matter between your ears and come to a comfortable decision. Only you know your situation.

BigKahuna · July 17, 2015

Your 12.7L Detroit keeps up with the newer higher rated engines because you've had the ECM tuned, as you've mentioned several times in other threads. With the point you are trying to make it's only fair to include all of the facts.

Bottom line is a 6.0 will do a fine job towing your trailer, performance will likely be close to what you're used to with the F150. If you're content with that, go with the 6.0 and don't look back.

If you want a truck that will move the load with a lot less strain, duramax.

I'd lean towards the 6.0, unless the extra performance of the diesel is more important to you than the drawbacks mentioned previously.

My main reasons for going with the gas was post warranty repair costs and simplicity, purchase price and daily driver use also helped me make the decision to a lesser extent. These were all more important to me than fuel economy or performance.

Brian Yoakum · July 17, 2015

Just recently updated from an 08 GMC 6.2L to a 15 Duramax. Wow - what an eye opening experience! I was so content with 6.2L with its high HP and Torque i never thought once I would ever need a diesel. Started looking at replacements for the 6.2L with mileage creeping up on 160,000 earlier this year and was just sure I would pickup another 6.2L - but when I finally made the move GM was on allocation for the Max tow package for the new 6.2L and 8 speed tranny. One dealership just said - why not take a look at a Duramax. I had already checked out a 15 2500 HD w 6.0L moter - but the gas mileage wasn't good enough ( 15 % towing - not heavy and 85 % daily driver). So- they said they had a truck on the lot they had been there too long and would make me a great deal if I liked it. To be honest - I had a hard time taking it back after my test drive and acting like it was "just ok". wow - the power and torque was amazing. The ride was sooo much better than I remember from my 03 2500 truck. Long story short - they made me a better deal on the Duramax than if I ordered a new 15 1500 loaded up the way I wanted. What i'm getting at is - get out there and test drive a few trucks and you will have a better idea what all of these other guys are talking about. Either way you go with a 6.0L or a Duramax that 10,000 # load you have 25% of the time will seam a whole lot less behind you and I really think you will enjoy the truck the other 75% of the time to.

Cowpie · July 18, 2015

Your 12.7L Detroit keeps up with the newer higher rated engines because you've had the ECM tuned, as you've mentioned several times in other threads. With the point you are trying to make it's only fair to include all of the facts.

Tuned, yes. But for efficiency, not for some gut wrenching power like folks generally assume is the result of a tune. That is the problem in analysis, folks come at things with preconceived ideas. This isn't some sort of Diablo or Blackbear kind of a tune.

My motor is still putting down 500 hp and 1650 torque, just as I stated. That is stock from the factory. I just fine tuned the injector timing and such to obtain better economy and efficiency. And I did streamline the exhaust somewhat which also helped with efficiency and significantly lower EGT's over stock setup when under a hard pull. So the example i used is still valid. Many of the 15L motors in commercial semi's today put down 200+ more lb of torque than my 12.7L Series 60. Now true, I am beating most of them in fuel economy, and that probably relates to the tune and the fact that the Series 60 has always been known as a fuel efficient motor. The tune just refined the stock tune to each injector. And when fuel is the primary cost of any trucking operation, and even small changes in economy can result is significant changes in profit margins, I was not interested in having some fire breathing motor that would lay down 2200 lb of torque and bust a clutch or a driveshaft every other week. I leave all of that kind of tuning to others who are trying to make up for low testosterone levels.

But it still pulls with, and sometime out pulls, many of the new motors. And that centers around the attention to detail in spec'ing the transmission and diffs to take full advantage of the motor. Most dealers and many fleets haven't a clue how to match up trans and diffs to more closely match the motor.

A Dodge Viper motor will lay down some very impressive numbers. But it can't pull squat. Partly the vehicle itself, but also because the transmission and diff ratio is not set up to pull serious loads. Just get the car out of the hole and moving down the road fast. Hook it up to a load in a truck pull that puts no tongue weight on the pulling vehicle and see how well it does, even with a beefed up hitch on the back. Warranty will not cover the busted drive train.

That is why engine power outputs are interesting, but how everything is matched up for the job is more important. Another analogy.... a 100 hp farm tractor would rip a Dmax equipped pickup apart in a tug of war. Again, the transmission and differential, etc. I would have no problem pitting a 40 year old John Deere 4020 against a 2015 Dmax equipped 3500 in a tug of war. The only question would be.... "do you want the back half of your truck back?"

Whip · July 18, 2015

Very good info that really helps me understand. I knew there must be more to the story than simply looking at the hp and torque numbers. I think the 6.0 would probably do a nice job for me. But I knew it I started looking at this stuff too much my bank account was in trouble. I found a smoking deal on a double cab truck with a Dmax engine and will be picking it up this afternoon.

Thank you for all the help and insight!

Cowpie · July 18, 2015

The Dmax is a good choice for many folks. And diesel fuel price in relation to gas makes it a real good choice. Keep us posted, and ENJOY!

redwngr · July 19, 2015

Very good info that really helps me understand. I knew there must be more to the story than simply looking at the hp and torque numbers. I think the 6.0 would probably do a nice job for me. But I knew it I started looking at this stuff too much my bank account was in trouble. I found a smoking deal on a double cab truck with a Dmax engine and will be picking it up this afternoon.

Thank you for all the help and insight!

Dmax makes it's max torque (765 ft-lb) available from 1600 rpm. When at highway speed this is about the rpm it will be running. Means the truck will rarely need to downshift.

Gas engines often need to downshift because the torque they are being askes to produce cannot occur at the current engine rpm.

Added bonus of the '11 and newer GM 3/4 or 1 ton GM is the massive service brakes.

Added bonus of the '11 and newer dmax is the exhaust brake.

Hook up the trailer, engage the tow/haul mode and exhaust brake, set the cruise and enjoy the trip.

Cowpie · July 20, 2015

That is all true! But in all fairness, the 6.0L has 90% of available torque at 2000 RPM, where it is running at highway speeds. If one has the need, the Dmax is a great choice. If one doesn't need that much, the. 6.0 is a great choice. Something for everyone! What was truly interesting, is that on the Ike Gauntlet Test done by Fast Lane Truck, the Dmax equipped 2500 only beat the 6.0L on that long pull up the mountain by 2.5 minutes. Now that either speaks that the Dmax is not all that strong, or the 6.0 is not a slouch. I opt for the latter assumption. They are both great in their own way.

Only thing that bothers me about the Dmax torque, it doesn't remain at peak over several hundred RPM. The typical heavy diesel reaches peak at 1100-1200 RPM, and remains at peak till around 1500-1600 RPM before trending down. I would have expected the Dmax to hold peak torque longer. The little 2.8L VM diesel in my '06 Jeep Liberty reached peak at 1800 and held it study thru 2200.

redwngr · July 25, 2015

You're a tough guy to please. Staying above 700ft-lb (or 90% of max) seems pretty good to me (not trying to diss the 6.0 which is also a great motor, but for a different job)

6.0 has a max of 380 ft-lb, at high rpm.

Cowpie · July 26, 2015

Yes I am. I spend hundreds of thousands of dollars on commercial trucks. I demand a lot from how they are spec'd. Max torque on a chart is one thing, max torque at the wheels is another. The two are not interchangeable. And I expect all of my diesels to hold max torque study over several hundred RPM. That allows max torque to be available to each gear on the shifts.

And while the Dmax does have considerably more torque than the 6.0L, it should have done much better than it did on the Ike Gauntlet pull test compared to the 6.0L. It only beat the 6.0L up the mountain by 2.5 minutes, or roughly 20% better time. Now, I don't suggest that the Dmax is bad. I take the opposite view, that the 6.0L equipped pickup delivers better performance in the real world than the charts would suggest. And yes, both of these were loaded up to 20,500 gross combination weights.

Take a look at the torque curve on the 2.8L VM diesel that was in my 2006 Jeep Liberty. See how it holds max torque over a 600 hundred RPM range as a diesel should.

2.8L VM.pdf

Or the torque curve on the Cummins 6.7L that Dodge offers. Again, you see it holding max torque flat over a range as well. As much as I hate Cummins, got to give this one credit, it holds max torque over a 1000 RPM range!!!

Cummins 6.7L.pdf

See the torque curve on my Detroit Series 60 12.7L diesel. Again, see how it holds max torque over several hundred RPM. It reaches peak torque at 1200 RPM and holds it to 1550 RPM. That 350 RPM range might seem small compared to the others, but you have to understand that the prime operating range of the Detroit 60 is 1200-1700 RPM. Only a 500 RPM spread.

Detroit 60.pdf

I have covered the spectrum from tiny Jeep diesel to heavy semi truck diesel. They do things similarly. Expecting the Dmax to hold max torque over several hundred RPM is not unrealistic, nor does it mean I am a "hard man to please". I just expect certain things and am critical when an OEM cannot deliver. The other folks can! You would think GM might have learned something from VM, since up till 2013, GM held 50% share in VM Motori.

Well, GM did learn a thing or two. Their new 2.8L diesel for the Colorado/Canyon pickups is a direct copy of the VM 2.8L that I had in the Jeep. Only minimal mechanical changes, and of course, more EPA stuff than the 2006 VM in the Jeep. Except for a Honeywell VG turbo instead of the Garrett VG turbo, and a slightly higher rail pressure, the 2.8L Dmax is a direct copy of the VM 2.8L.

2.8L VM.pdf

Detroit 60.pdf

Cummins 6.7L.pdf

Badass69 · July 26, 2015

Say no to the L96 rpo code.... Sure it will usually run forever as most half decent LS engines will, but the rectangular port heads and 4" bore are useless in a heavy truck. The intake valve is very heavily shrouded and you have a cylinder head with port flow well beyond what that small cam 6 liter ever could use. I used to joke my 09 2500 hd had vtec... turned on about 4500 rpm and shifted at 5600... Anything below that with weight on it especially was painful. The ecoboost will walk all over the 6 liter for pulling power... it's not even a contest.... even with 3.55's in the Ford. The transmission ratios between the 6L90E and the 6R80 are identical so even with the lower rear end ratio in the Chev it will not make up for the lack of power and heavier truck it's moving. Not to mention the broader low rpm torque curve the Eco has versus the 6 liter.

If you feel the Eco struggles at altitude wait until you get that naturally aspirated turd up in elevation.... you will want to toss a tow rope to passing traffic. Stick with what you have or buy a diesel if you feel the half ton chassis is inadequate for job.

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therink · July 27, 2015

I have owned 3 6.0 GM HD trucks with 4:10's (last was a 2012) and now my 15 3500HD Duramax. I tow a 12,000 lb fifth wheel rv.

The 6.0 with 4:10 was/is a great set up and is made to tow. The truck frame, brakes and suspension are also made to tow (a significant improvement over any 1/2 ton truck). My 6.0 never let me down, but it was thirsty.

The Duramax on the other hand is a whole different animal. It comes down to choice and $ and if you tow enough to justify the extra nine grand.

I will say that now I have gone to diesel, I never want to go back. The Allison and exhaust brake are awesome.

Cowpie · July 27, 2015

Guess you didn't see the Ike Gauntlet pull test videos and analysis, Badass69.

The Dmax does do the heavier jobs better, especially in tough terrain. The key is, with all that it requires, along with the additional cost, one has to determine if it is really needed. Many can benefit, and justify the additional cost in both purchase and maintenance, with a Dmax. Some of us, it is overkill for our needs. I have no interest in pulling trailers over the Rockies or even the Appalachian's and cannot see it in my future in this life. The most I would every tow is about 12,000 lb, and that would be no more than a couple of hundred miles at the very most, mostly under 100 miles, and done so in the midwest. But even that 12,000 is a stretch. A compact tractor / loader on a trailer doesn't touch 10,000 lb. I suppose a 6.2L 1500 could have pulled that comfortably, but I mostly haul, so I needed more than a 1500 could haul. A 1500 doesn't do too well when you slide a ton of bentonite or quikrete in the back. So the 6.0L / 6L90 / 4.10 does a great job for my needs. I just use diesel for the compact tractor and my semi trucks. I have no desire to play with the emissions junk and other stuff on a pickup diesel. Just isn't cost effective enough for my needs. I get all of that I can stand with my semi trucks, and there really isn't any practical alternative to diesel with those.

Then there are those that just like the fashion statement diesel makes. I guess that is ok. And from what I see on a daily basis, that seems to be the primary reason many buy a diesel. I cover about an average 2800 miles a week in my semi, and I sit high enough to see into pickup beds, and I see hundreds of 2500/3500 pickups every week. It is a very low percentage of diesel pickups that have a 5th wheel, gooseneck, or even evidence it has ever had one, in the bed. And the receiver hitch looks like it has hardly ever been used. The vast majority of fleet type working 2500/3500's are gassers by a 3 to 1 margin, even those with construction bodies hauling quite a bit and towing trailers. Diesel has it's place, for sure, but it is not necessary for many folks. I guess going thru an average of over 20,000 gallons of diesel a year like I do, the luster of owning diesels wore off quite some time ago, especially since the EPA decided to force the emissions stuff down our throats. To me it is all about practical, cost effectiveness, etc.

Badass69 · July 27, 2015

I have watched all that trash... I don't really much care. Those goobers that do that show are aggrivating... but at least they make fun of themselves I guess. The op is pulling a trailer well within the confines of a half ton truck. He wants a little more cushion so it wouldn't surprise me if he has 1500 lbs or less payload... which can be frustrating. However he says he is still perfectly legal. So the fact you can load 2500-2700 lbs in the bed of a gas 3/4 ton really is of no concern... nice sure... but probably of no matter. I personally would never own a diesel pickup of any kind period. ... but I am not the majority of people that buy them to do nothing with. I just don't buy stuff that struggles to do what it is intended for... my last couple 07 up 6 liter gas pots were pathetic with the same load in the bed of equipment that I run in an F150... legally by the way... so I was in no way taxing the 3/4 ton truck before nor am I taxing my half ton now. I have an 1850 lb payload on my current work rig.... that's plenty for me but I do haul a bunch of gear. I am 400 lbs below my legal rear axle weight and the truck sits level.... like I said... didn't tax a 3/4 ton even if it drove like it did. I am not an average commuter that hitches on a holiday trailer 3 times a year lol. Buy what suits your needs... but for reasonable power which the op was even commenting on regarding the ecoboost in a higher elevation. .... Well. .. if a turbo engine that loses less at altitude and had more power was feeling taxed.... . a 6 liter 3/4 ton is going to even be more frustrating for him. That's the only reason I mentioned a diesel.

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