For years, the Ford Motor Company has held the crown of having the burliest diesel in America. The high-output version of the 6.7-liter Ford Power Stroke V8 with 500 horsepower and 1,200 lb-ft of torque beat the rest of Detroit in power, and not exactly by a small margin. Today, General Motors has announced the final answer in diesel pickup truck engines. The new 8.3-liter Duramax V8 diesel engine isn’t just the biggest diesel fitted to a mass-production pickup truck, but it puts Ford into a solid second place. Yet, there’s one metric that, despite GM’s best efforts, it could not beat Ford on.
The rumor mill has been busy printing out speculation about the future of Duramax diesel engines for longer than two years now. Back in January 2024, the Fast Lane Truck (TFL) reported that “a source with knowledge of GM’s internal powertrain development alerted us to a new, bigger, and far more potent powertrain about to emerge as the new king of the hill: a massive, 8.3-liter beast.” There was a lot of skepticism following the publication of TFL‘s news, with some, including GM enthusiast blogs, concluding that chasing best-in-class power numbers was more of a Ford thing. TFL nicknamed the project “Megamax” in its coverage, which was fitting.
As it turns out, TFL was right from the jump. While GM did not confirm to TFL that it was designing a new, bigger Duramax diesel engine, it was secretly working to create the very engine that someone leaked to TFL. The real engine does not make 600 horsepower as originally speculated. Instead, it still puts out more than enough thoroughbreds and twist to unseat the Blue Oval from its long-held throne. In the process, it has also built an engine that, so far as I can tell, is the largest diesel engine ever fitted to a mass-market production diesel pickup truck in America.
The Rumor Mill’s Rumored Mill
The Fast Lane Truck got Chevrolet Silverado and GMC Sierra fans excited for what sounded like the impossible. In 2024, TFL explained the rumor they heard and why it was a big deal:
As for the headline specs, we’ve been told this new 8.3L diesel engine (which we are calling “MegaMax” — there’s no indication that’s the name GM has in mind for it) puts out up to 600 horsepower and up to 1,200 lb-ft of torque.
For reference, the current 6.6-liter L5P Duramax turbodiesel available in 2024 and newer Chevy Silverado and GMC Sierra HD models manages up to 470 horsepower and 975 lb-ft of torque, according to SAE J1349 power and torque certification measurements. If the automaker does see such an engine through to serial production, GM would leapfrog ahead of Ford, whose 6.7-liter Power Stroke diesel V8 cranks out 500 horsepower and 1,200 lb-ft of torque in its high-output form. Despite packing two fewer cylinders, the 6.7-liter H.O. Cummins in Ram’s heavy-duty trucks produces 420 horsepower and 1,075 lb-ft of torque.
Ram’s heavy-duty pickup trucks have since upgraded to 430-horsepower mills, but GM’s L5P Duramax has stayed the course with its output. This put General Motors in a weird position in the diesel pickup truck market. It couldn’t touch any version of the 6.7-liter Ford Power Stroke V8, and only bested the Cummins on horsepower.
Yet, understandably, some didn’t believe that GM would go as far as to make a mammoth diesel to rule them all. While the 6.6-liter Duramax V8 was technically third in its field, it wasn’t like the Silverado and the Sierra were suffering. They still benefited from a 36,000-pound towing capacity in a properly equipped truck pulling a fifth wheel or gooseneck trailer. Sure, this was 4,000 pounds short of the Ford F-450’s headline-grabbing 40,000-pound limit, but 36,000 pounds is still tons of weight for a pickup truck to haul. For reference, a Ram 3500HD pickup truck could tow up to 36,610 pounds with a regular cab, a 6.7-liter Cummins straight-six, and a long bed. The best towing configuration for a Ford F-450 is similar.
Apparently, General Motors did not agree with the notion that the L5P Duramax V8 was enough by itself, because its DMAX division has taken the biggest of swings by crafting a whole new 8.3-liter V8 diesel engine from a clean-sheet design.
The ‘Mongoose’ 8.3-Liter Duramax Diesel V8
General Motors says that the new engine, codenamed “Mongoose,” was designed from scratch in-house specifically for the heavy-duty pickup truck market. The 8.3-liter engine sports a compacted graphite iron cylinder block, a forged crankshaft, forged connecting rods, and steel pistons. GM says the engine’s new architecture features an integrated intake, an “advanced combustion system,” and crankshaft isolation for reduced noise and vibration. It also features a compact dual-stage air-to-water charge cooler, a high-efficiency variable-geometry turbocharger, and upgraded engine cooling.
Backing up all of these goodies is an Allison 10L1000 10-speed transmission, an exhaust braking system, and a diesel aftertreatment system that’s supposedly fit for a truck that lives a hard life of towing and hauling. It all adds up to a behemoth 8.3-liter diesel V8 that pumps out 555 horsepower and 1,230 lb-ft of torque. For those of you counting, this readily beats Ford’s best and leaves Ram in the dust.
It also has the distinction of being the largest diesel ever offered in a mass-market pickup truck in America. I’ve done some digging, and the closest that I could find was Ford’s own legendary 7.3-liter Power Stroke V8 of the 1990s and the 2000s. To be clear, the semi-tractor market has had much larger mass-produced V8 diesels, like the 12.1-liter Detroit Diesel 8V92 and Scania’s whole range of V8 diesels, which reach as high as 770 horsepower and 16.4 liters of displacement. The 18-liter Caterpillar 3408 is another seriously chunky V8 diesel.
Historically, however, the diesel pickup truck market in America has had smaller diesels than their big rig and construction machinery counterparts. So, a mega version of the Duramax is pretty wild. As for that name, well, that one is just GM picking its target. The mongoose is a predator to the scorpion, and “Scorpion” was used as Ford’s codename for its 6.7-liter Power Stroke engine.
General Motors says the new engine is a rather huge deal. The automaker invested $920 million into its Duramax diesel program to enable it to create this behemoth, which will be built in the GM DMAX complex in Brookville, Ohio. In describing the new engine, GM says that “The all-new available diesel is GM’s first clean-sheet HD V8 designed, developed and manufactured in-house for heavy-duty pickup applications.”
As I have written in the past, the Duramax diesel dates back to a partnership between General Motors and Isuzu that minted its first production engines in 2001. What’s interesting is that some sources say that the L5P Duramax engine, which went into production during the 2017 model year, is a clean-sheet design. Other sources say that it’s merely a “near clean-sheet” design. GM’s claim would seem to support the idea that previous Duramax diesels at least had some of the original GM-Isuzu DNA still left in them.
The new engine isn’t all that’s coming for 2027. GM says it has announced the heavy-duty pickup truck segment’s first electric power steering system for its new Sierra and Silverado pickups. According to GM, this new rack and pinion system provides 30 percent more steering power than previous hydraulic systems, while also offering fine-tuning through drive modes, improved on-center feel, and less kickback on rough surfaces. The electric power steering system is reportedly also built to take some hits and survive the worst that America’s saltiest roads could throw at it.
Another new feature is an electronic brake-boost system, which GM says is another first in the heavy-duty pickup truck market. The new trucks will come with four-piston calipers up front, which will chomp on 14.6-inch rotors. The big brakes are said to have a better thermal capacity, while the electric brake booster reduces pedal travel, makes pedal feel more linear, and allows for better integration into active safety systems like adaptive cruise control and automatic emergency braking. While perhaps not of the most importance in a heavy-duty pickup truck, the electric booster also shaves some weight compared to a hydraulic version.
Finally, off-road versions of GM’s heavy-duty pickups, namely the Chevrolet Silverado ZR2 and the GMC Sierra AT4X, will be getting a new Terrain driving mode that will allow for one-pedal off-road driving. While this feature is new to GM, its competition, like Ford, has had a sort of off-road cruise control in heavy-duty pickup trucks for years.
For those who don’t like diesel, General Motors says it’s also updated the 6.6-liter gasoline V8 for 2027. GM says that the updated engine “gains horsepower and torque, with improved low-end pull and updated emissions hardware supported by a new Turbo-Jet intake manifold, revised lubrication system, engine-mounted oil cooler and digital oil-level display.”
GM neglected to say just how much horsepower the updated 6.6-liter gasoline V8 will make. It also doesn’t say if the digital oil-level display means that the engine won’t have a dipstick. I have reached out to General Motors for clarification on these figures.
Ford Still Beats GM In One Metric
The big number is towing. General Motors says that properly equipped 2027 Chevrolet Silverado HD and 2027 GMC Sierra HD trucks will have 20,000 pounds of conventional trailer towing capacity, and up to 38,000 pounds of gooseneck towing. The 20,000 figure is unchanged from the current-generation GM HD pickups, while the latter number is a 2,000-pound upgrade. Notably, this means that, despite having the biggest engine in the business, GM’s trucks technically still tow less weight than the 40,000 pounds that can be hauled by a properly equipped Ford Super Duty.
Still, the gap is now only 2,000 pounds, and I’m sure there will be plenty of truck buyers who won’t care just so they can say they bought the biggest, baddest, and most powerful diesel on the market. Also, the Ford’s win is only a technicality, as it’s on the F-450 chassis. GM doesn’t sell trucks with pickup beds past its 3500 class. However, the towing upgrade does mean that the Chevrolet Silverado 3500HD and its GMC twin can now haul the same weight as an equivalent Ford F-350.
But why? In a world where diesel is seen as old news, and high diesel prices break records, why would GM introduce this colossus?
As Automotive News explained recently, it’s because General Motors sees a future in diesel and is doubling down on the technology in both light-duty and heavy-duty pickups:
“It’s not one engine for everybody,” GM President Mark Reuss said during a media event at the company’s engine plant here. “It’s the freedom to choose the engine that fits your work, lifestyle and priorities.”
For Silverado and Sierra buyers, GM sees its diesel powertrain as having some advantages over a hybrid option, including driving range. The redesigned pickups’ Duramax engine allows more than 900 miles of highway driving on a 34-gallon tank. “If you look at the performance and efficiency but also raw performance and range, hybrids really don’t do it,” Reuss said. “It’s a bit different adding a hybrid system to an existing powertrain and trying to get the efficiency out of it like that.”
“Different customers need different combinations of capability, range, affordability, towing confidence and convenience,” Reuss said. “Our aim is to meet them where they are.”
As a note, GM was still being secretive about this new engine when that Automotive News article was published. The range figure stated above is for the Duramax 3.0-liter engine.
Additionally, as General Motors says, over 60 percent of its heavy-duty truck buyers opt for diesel, and it also sells the most diesels in the heavy-duty pickup truck segment. To GM, making a herculean V8 diesel just cements its place in the diesel world even further.
So, while Ford, Toyota, and Ram commit to hybrids, General Motors is going the opposite direction. It remains the only automaker in America with half-ton diesel pickup trucks on the market. Now, this monolith of an engine is going to be a monument to oil-burning power.
As for the awkward situation of how this engine is going to launch into a market with historic diesel prices, it’s pretty clear that General Motors has been working on the Mongoose for at least a couple of years. Today’s diesel prices are an unfortunate coincidence.
If diesel prices aren’t stopping you from getting a new diesel truck, and you want the one with the largest lump of diesel under its power barn, GM says that its 2027 heavy-duty pickups will ship to dealers late this year. Should you be one of those who go all-in on diesel, you’ll be getting an engine with a displacement so huge that each cylinder has more than the volume of one of the engines out of my Smart Fortwos.
That’s just silly, and honestly, I’m here for it. Only General Motors could have concocted an idea this crazy. In a world of hybrids and electric cars, the General is making a huge bet on diesel. It’s even wilder to think about when you realize that GM could have made an extended-range electric truck, or maybe even a diesel-electric hybrid. But nope, it instead decided to make a hilariously huge lump of diesel power.
Will GM’s bet pay off? I have no idea. I know I shouldn’t like this idea, but I’d be lying if I said I didn’t want to be the first journo in line to test it.
Top graphic images: GM
Insane.
Someone explain to me why brands peacock pickup trucks with justification that we need engines outputting more than commercial transport semi-trucks rather than more reliable/lower maintenance engines?
I’d add that the transport semi-trucks that are capable of towing more, suffering far more abuse than you’ll ever throw at a pickup truck, and still be more reliable at the end of the day.
Is this the pickup truck version of having a Dodge/SRT Viper?
It’s for Real Big Boys with Real Big Wieners to drive around town.
My mum is going to be so proud.
Only in the sense that a large displacement is a virtue (this engine is less power dense than either Ford or Ram).
People can say what they want about Vipers, but they aren’t a car you buy to brag about to others. They’re (mostly) difficult to drive and live with.
One reason is that these can also slip into a gray area for hotshot style trucking setups where it slips under various regs for commercial trucking vehicles.
Anyone doing commercial driving with a vehicle 10,001 lbs and over is required to keep hours of service logs and limit their hours accordingly. GCWR 26,001 or over and you need a CDL
There are some exemptions but anyone driving as a hotshot would not qualify.
This seems like betting on the wrong horse for the long run. But GM has probably done some research and determined that for the life of this engine family (10-20 years?) there will be a market for diesel, and they want to stake their claim. Eh… I am not the target market.
I spent a few years driving company F250s with the 6.7L
PowersmokePowerstroke and it was a decent truck. Too big for my personal tastes, but plenty of power.I imagine the GM 8.3L will be even more powerful. I wonder if this engine/trans combo will be available with a PTO, as that would be useful.
What does useful have to do with anything? This is a phallus measuring contest-mobile.
The PTO would be useful if it were available. Those usually aren’t available on the gas engines.
I’d be shocked if the PTO wasn’t available.
“It also doesn’t say if the digital oil-level display means that the engine won’t have a dipstick.”
Take a look at the front view of the engine. There is a dipstick present in the image
Important question – does it have a dipstick?
Just the buyer…
I’d imagine that the average buyer is rather self conscious about their dipstick
…and they don’t seem to dip their sticks often enough to keep the rage at bay.
Why do we need these? Really. I once made regular cross-country drives for my job, and these rigs are all driven by ‘Hotshot’ drivers with 5th wheels. In my experience, Dodge and Ford were the preferred brands. Why do we need this much more than what was more than suitable 5 years ago?
The F250s used by where I used to work had PTOs and had a 240VAC 12 KVA generator attached to the PTO for onsite power generation. But once the F250s were ‘upgraded’ to the 10-speeds, the generators would no longer fit, so the company kept with the 6-speed models.
25+ years ago a steel mill I worked for was looking to replace it’s on-site fleet. These trucks never saw public roads – the in plant speed limit was 15 mph. It was a small fleet of worn out Bull and Bricknose Ford F250/350 flatbeds or service bodies with the 300 I6 and a C6 auto. I think a couple of the F350’s had 460’s or 351’s. The maintenance supervisor’s truck (the one I shared) was the only one with A/C and a radio. By the turn of the century, no domestic automaker sold such a bare bones-basic work truck. These service fleets do not need computer controlled overdrive transmissions with 10 speeds and 500 hp diesels. They need a Ford 300 and a Powerglide…
The Powerglide was GM. But I agree. Our work trucks never had more than a few hundred pounds in the bed and never towed anything.
The only reason they were F250s with the 6.7L diesels was to get the PTO for the generator.
I know I’m mixing manufacturers – my point is that there is a BIG need for just simple FARM/WORK vehicles without all the fuss. Almost any factory or farm just needs a low speed/medium payload fleet with no tall bedsides. EV are honestly perfect for this application.
I agree. And I know F*rd makes a regular-cab F150 and Chevrolet makes a regular-cab Silverado and they’re both available in basic work truck versions with 8-foot beds.
But they’re both close to $40K and that’s just not an acceptable price point for a 2WD basic work truck.
This is why the take rate is so low for regular-cab trucks. Plus the fact that stealerships rarely have any on the lots.
GM still has the 4.3 V6 in the Express van. If they put that motor/trans in the RCLB 2WD Silverado and sold it as an actual real work truck for $29K, workers and farmers would buy a lot more of them.
I’m sure F*rd and RAM could do the same with the F150 and whatever RAM calls their full-size trucks nowadays, but none of them want to offer a full-size truck for under $30K as it would cut into their healthy profit margins.
So true – maybe even hololomgate for Off-Road use only. I support clean air and better efficiciency across the board, but current regs are killing these other justifiable use cases.
Ford could still sell the OBS, Chevy the Squarebody to these (not) niche users.
If this BIG need really existed the market would supply that demand because… money. You are just spewing the typical Luddite tropes of the automotive realm. There is nothing wrong with this desire and I share some of the sentiment.
I don’t see the relevancy. I visit a lot of industrial facilities that I visit use kei trucks for their maintenance facilities. They work great when your top speed it 15 mph. Likewise, at an airport, a 100hp lump with the proper gearing will transport anything you might need short of the plane itself. A Unimog is probably a textbook example of this. That 300 I6 will not tow 35,000lbs down the highway at 65 mph no matter how strong the tailwind is. The 3 speed auto (c6) will puke it’s guts while getting 1/2 the fuel efficiency of a modern 10-speed.
I’ve spent 30 years working at facilities like what you describe. The fraction of trucks that serve in this capacity are a fraction of 1% of total truck sales. Small tractors or golf carts would work better in this application. I’m not sure what the point is.
We had experience with John Deere and Kawasaki vehicles. They always broke. Many times the old Cushmans and golf carts were too small or unsuitable for the ‘roads’ outside of the buildings. This was a several hundred acre facility with basically unimproved roads linking vast buildings. Also, we did have pumps, etc… that needed loaded from a warehouse by crane and an F550 to haul across the site. Old OBS F250’s seemed to strike the balance we needed.
What we didn’t need were overdrive transmissions, ABS, traction control…. We needed a torque heavy 300 I6 and a 2 or 3 speed auto.
I won’t argue with the specifics of your facility, but I contend that your use case is a few hundred vehicles across the continent per year. There are only so many steel mills/paper mills/etc… that need high payload and low power vehciles. Tractors and other specialist machiens work for most of those applications.
Family farms? Oil and gas wells? Railyards? Places where A/C and a roomy cab would be nice, without any regular need to run at highway speeds.
Not where I live or the places over North America where I work. But in a hypothetical world, there is a market for thousands of such low powered high payload vehicles.
If I’m doing that kind of driving work – hotshot trucking – I’d go for the most capable setup. Cost of the truck is all business expense. More power and torque means the engine is working below its design limits more of the time which means all else being equal its going to be more reliable. I get it. There will be some but probably not a whole lot of these just used as “drivers.”
Can’t wait to spend $300 to fill the tank on one of these bad boys just to use it to drive back and forth to work 95% of the time.
But you may need to tow a small house at some point. Better safe than sorry.
Well what happens if you see a house that has fallen into the ditch? If you can tow that house out of the ditch JUST ONE TIME, the GLORY you’ll get will make it all worthwhile.
Over 26mpg is a pretty big claim when you aren’t required to publish fuel economy on HD pickups.
I bet he was referring to the 3.0L Duramax in the 1500s. That 900 mile range was talked about a lot at the recent media gathering for the new 1500
“ As a note, GM was still being secretive about this new engine when that Automotive News article was published. The range figure stated above is for the Duramax 3.0-liter engine.”
“It’s the freedom to choose the engine that fits your work, lifestyle and priorities.”
Well I guess I’d be buying an EREV from RAM then.
What will I ever do with my Duramax that “only” makes 260 hp / 525 lb-ft?
Any word on whether or not the current 6.6L carries over or if this is the only option for someone that wants a diesel in a 3500HD. The 6.6L gas engine is the engine to pick for those that care about TCO.
The 18,000 pound tow rating on the gasser can be maxed out faster than you think. I agree that if you don’t need any more than that, the 6.6L gas is the better option.
That is what real commercial trucks are for. A pickup pulling 25K, 35K, 40K on the regular isn’t going to last long and you can’t tell me it is actually safe.
I have 30 1-tons registered between 26,000 and 43,000 lbs. A truck, tilt trailer, and construction equipment is easily going to exceed 26,000 lbs. The current HDs and Superduties can handle it.
Do they handle it for 500K or more miles?
Do they need to? There is a guy on youtube (PD Diesel) that has a fleet of diesel pickups in the NW that runs up 400,000 to 700,000 miles with F-350 and Ram 3500 trucks. He details repairs and breakdowns. Good info, but Turbeaux references trucks hauling construction equipment. Those trucks haul to a jobsite and then sit until the end of the day. Hard to imagine that they would rack up 500,000 miles, but the truck is a tool and its job is to haul back and forth to that jobsite. I don’t see any reason that this 8.3L wouldn’t do 1/2 million miles under reasonably heavy loads. I would expect the same out of a modern 6.6 or 7.3L gasoline engine that was properly maintained.
Yes company vehicles are tools and the name of the game is total cost of ownership. The longer a tool lasts the better.
My point is that a company vehicle need to last as long as it is fully depreciated. This could be 200,00 miles of 500,000 miles depending on how many miles it is used per year.
“What will I ever do with my Duramax that “only” makes 260 hp / 525 lb-ft?”
You will use it to drive your sorry emasculated self (if the truck can even handle it with that weenie torque figure) down to the nearest GM dealer and get your deposit in on one of these so you can stress about a $1500 monthly payment but finally feel good about your T levels, patriotism, and status among people you’ve never met.
I mean, c’mon. Obvious answer is obvious and I don’t know why we’re having this conversation.
“You will use it to drive your sorry emasculated self (if the truck can even handle it with that weenie torque figure) down to the nearest GM dealer and get your deposit in on one of these”
There is another option… he could just accept that he’s not ‘manly enough’ and become a Transvestite.
“What will I ever do with my Duramax that “only” makes 260 hp / 525 lb-ft?”
You’ll just have to become a Sweet Transvestite since you’re not manly enough with just 260HP.
To be fair, Ford kinda cheats at the “max towing for a pickup” game by putting a pickup bed on a 450/4500 class truck. Neither Chevrolet nor RAM offers a 4500 with a pickup bed.
It’s all peacocking at this point anyways. If my in-law’s old 2006 3500 Duramax could tow a 27ft 5th wheel camper without breaking a sweat then a new engine with double the torque is just there for bragging rights.
Bingo. Let’s start towing drag races – oh yes, these actually exist.
Why does that not surprise me…
You’ll need a LOT more power if you wanna go hang with the drag racing big rigs. Especially the boys that come down from Quebec.
https://www.youtube.com/watch?v=k3d1FVMTufw
Except the new trailers are all 40′ and weight significantly more. Trailers, just like cars, expanded.
a 27′ 5th wheel is 1/2 ton territory now.
It may be academic for that purpose. I work closely with a company that has a fleet of 1-ton pickups and flatbeds. They haul 48′ mobile labs, and gooseneck trailers full of pumps and pipe all over North America. Their guys tell me that the latest Duramax was a huge improvement over the previous 397hp version. They now have F-350s in their fleet that they are quite fond of. For them, it’s about turnaround time from one job to the next, and DOT only allows a certain number of hours/day whether they drive 55mph or 70 mph.
What’s hilarious, is that the F450 has a better turning radius than the F350.
Cause it’s a wider front axle, which allowed more angle before fouling on any components.
This just doesn’t add up to me… am I mathing wrong? 900/34 = 26.5 MPG. That sounds right for the 3L Duramax, but no way that’s true for either of the V8 Duramax engines…
Agreed. There is no way this monster is getting “more than” 26.5 mpg
Yeah as other’s have commented, after re-reading the quote block it looks like it was referring to the lack of hybrids on the 1500 series trucks and the 3L engine, which makes a lot more sense. These HD diesels will get 17 MPG highway on a good day.
That was in a press release about the new 2027 1500 trucks and it only applies to the 3.0 engine. Mercedes was just using that quote here.
Beat me to it by a few seconds while I was typing up the same comment.
That is my bad for not clarifying the quote there! When GM was bragging about doubling down on diesel to Automotive News, it was still being secretive about the bigger Duramax. The range figure stated in the quote is for the half-ton.
The quote about range and thus inferred mileage should just be removed, it is entirely irrelevant to the discussion of this engine and even with the explanation will be misunderstood and requoted.
I am curious as to what the reason is for the extremely large displacement. Ford and Ram both use a 6.7, for GM to be jumping up another 1.5L of displacement and only be up 55hp and 30lb-ft of torque really raises some engineering questions. Is it a matter of just having a really under-stressed engine? Does engine size come with reduced emission restrictions? Is GM just unable to make a similar sized engine that is equal in output?
To be fair I’m not in the market for one, and likely never will be, just an interesting aside that it is taking.
You can’t advertise the largest engine in class without the extra displacement.
I’m picturing like a 4ft by 5ft engine that has a only 1.2L of displacement.
Physically largest engine in class
You are basically on the right track. Better cylinder pressures, less boost, lower egt’s. All of these things improve reliability and can reduce emissions, NOx being the big one. This engine is likely expected to last without significant changes for many years. Emissions are tightening and the Ford and Cummins engines are likely at their limit in their current version. I would bet the others have new revised engines in the pipeline with similar strategies of larger displacement and only modest power bumps.
Cummin’s ISL9 (8.9L) maxes out at 450hp and 1100ft.lbs of torque. But will output that for hundreds of thousands of miles in heavy duty service (stop & go transit buses).
So yes, longevity comes with displacement.
Yet this pickup truck engine makes more HP and Torque than that old commercial L9 and Cummins new X10 that will replace it. This engine isn’t about reliability though building a large displacement low stressed engine.
It is designed to move comparatively less weight over fewer overall miles.
The GVWR of a GM truck is the curb weight of an unladen 40ft transit bus.
Also, commercial customers are different. The medium duty chassis versions of the Duramax are often detuned compared to their pickup truck counterparts.
Yes, commercial vehicle and pickup buyers are completely different customers. Which is why the diesels in pickups are tuned way up to complete on specs while the commercial diesels are built based on longevity and cost of ownership.
Crazy these diesels are pushing as much or more power then a semi diesel and almost as much torque. Really wonder what the fuel economy will be on these though.
That has been the case for years but there is a huge difference in lifespans and warranties.
The Cummins B6.7L sold for commercial applications tops out at 300 hp / 750 lb-ft and those special applications. The typical commercial medium duty tune is 250 hp / 660 lb-ft.
Isn’t the rough rule of thumb that a semi engine will get a rebuild at 1M miles and a replacement at 2M miles? If I’m going by the hotshots we use at work, they are typically doing rebuilds every 400k miles or less even and the trucks are pretty much end of life at 1M. Or are transmissions driving that more frequent rebuild cycle and the engine is a “might as well” type thing at that point?
I know for our used truck center they normally get the fleet trucks back with 400-500k miles. Doubt many big fleets even care about rebuilds rather just trade it in get a new one and move on. Then again I may work for the bargain bin company of the US semi industry so makes sense the likes of Walmart or JB hunt wouldn’t want to be dealing with rebuilds for our cheap ass trucks. I am sure smaller fleets/owner ops will be looking more into the premium brands where they are looking at keeping trucks for 1mil+
Also I am in R&D not on the business end so take all what I say with a grain of salt. Most what I hear is just from emails and talking to the business type peeps.
The B10 life on the engine in a Class 8 truck is 800K to 1 million miles (Designed so that 90% will go that mileage without touching any internals.) The smaller engines in Class 5-6 trucks are about half that.
Large fleets running on-highway will buy or lease a new Class 8 with a 400K to 500K warranty and then turn it in or sell it when the warranty expires. Extending out the warranty to 500K is pretty cheap.
Are your hotshots real commercial vehicles or pickups?
The vast majority of hotshots we use are 3500 series pickups towing goose necks for long haul delivery.
That is what I figured given that you were rebuilding engines in less than 400K miles. How long are you getting on an DPF? Highway driving certainly will help but I can’t image they last long and the ones in trucks aren’t rebuildable.
No idea. These are all 3rd party guys I just make small talk with while the trailer gets loaded. I’ll have to ask the next guy.
Oh I’ll bet these will struggle to hit double digits….just in time for record diesel prices too! What really amuses me about the truck displacement arms race is that one of the real benefits of turbo diesels is fuel economy. They can return hybrid-esque mileage if designed correctly and you drive accordingly.
I’ll bet GM could more or less put the Babymax on a high protein diet for this application and have a truck that flirts with 20 MPG. But why do that when you can have the biggest, girthiest, hnnnnnng uhhhHHHHH…engine on the block?
It has been fun to watching the driving habits changes from all the diesel brodozers around me that used to drive around like their 6in lifted truck was a race car. Now they are all being conservative as hell and trying to not give much throttle. The gaser rams on the other hand are still driving like a holes though.
Also is funny because as I have said on here before my 1st Gen cummins normally gets 20mpg when driving 55-60mph same with old 6.2 Detroit and sure these are older “underpowered” diesels but still. Even modern diesels I am sure you could achieve this but they are all 4×4 and lifted, and tuned for to much power/torque so good luck getting anything past 15mpg (when not towing that is)
I’ve gotten 21-22 MPG out of my L5P Duramax. It’s all about staying on the freeway.
Your friend is actually doing 33% better than you. However you are doing 25% worse than he is. Same numbers, just depends on the perspective. 🙂
Horsepower, sure. Not even close on torque.
X12: 1,700 ft-lb
X15: 2,050 ft-lb
True for what I work on depends on the tunes. I know our tunes for our engines are from like 370hp/1250tq on the lower end up to 515/1850.
For sure.
GM and releasing a compelling product at the absolute worst time possible-name a more iconic duo
If GM can GM then GM will GM.
GM and pulling a product as the segment gets hot?
GM and fixing a product with a whole lot of issues, making it competent and competitive, then pulling the plug after one year.
They should write an article compiling all of the vehicles GM has done this to.
GM having all of the components for a segment leader but never putting the right combination of features together.
I’m still shocked that none of the big 3 have tried electrifying the turbos
I can’t imagine why. There’s so little spool time in an engine that has no vacuum or throttle plate.
I believe they are all variable geometry/variable flow turbines these days. Cummins definitely is.
Electric turbo would be more implementable on a 48V architecture or a hybrid setup that can easily supply the higher voltages.
Imagine the amount of snow this thing can plow!
Snow Plow | Truck Tunes for Kids | Twenty Trucks Channel | Snowplow – YouTube
GM needs to bring back the Fiero so that this engine could be an option in it.
This engine probably weighs about as much as a Fiero.
That’s exactly the point.
This can work if GM is wise and pitches this (if true) as a low cost of ownership option instead of the latest penis pump. i.e. high-po numbers in a slightly destressed engine with oversized injectors, and emissions systems that are more durable for the output than other trucks. Sounds like this is not that, but we’ll have to wait and see.
Low cost of ownership would require a low purchase cost/low financing payments, high fuel economy, low insurance rates,…
Nothing about this engine is targeting low cost of ownership.
Maybe. Maybe not. I don’t know. That being said, you are probably right. Just wishful thinking that this displacement lets them oversize components for longevity.
The new Cummins X10 is rated between 320 to 380 hp and 1,000 to 1,250 lb-ft for Class 5 and 6 trucks.
This is 555 hp and 1,230 for a pickup.
The number of people who can afford this and the flatbed full of side by sides must be getting smaller by the day.
Tax write-off for farmers and ranchers.
And a lot of other business people, Hell my buddy sells insurance and he as a F-350 platinum diesel he rights off as a business expense.
Which is a bit odd. The tax deduction is based on bed size and GVWR. There is no reason to spend extra money for fancy leather seats. Also when that truck is sold or traded the entire sale price counts as regular income because the section 179 deduction is “recaptured”
He likes the luxury.
Which is fine if he is willing to pay for it.
I’m often surprised at how many people don’t understand how tax deductions work. Spending $100 to save $20 in taxes never made sense to me.
agreed 100% some people just hate taxes and would rather burn money than pay taxes on part of it. Like my BIL who flew to europe to avoid a small visa renewal charge.
That’s why you lease it. *I’m not a CPA and this is not tax advice*
Nice! Good for him.
For the demanding type who want a truck they can live with but also if they need to enter a tractor pull event.
There are whole videos dedicated to showing Chevy IFS’s coming unglued at truck pulls.
I will be very interested to see what the emissions and longevity of these larger engines are compared to their predecessors. It seems like the math maths since it’s not just the American car companies increasing displacement.
And the obligatory, I want this in a muscle sedan or coupe. Pls GM? For me!?
The L5P weighs 835 lbs dry. I’m pretty sure you don’t want that in your muscle sedan/coupe.
For comparison the LT2 is about half the weight.
Diesels (and gas engines too) just keep getting more and more powerful, and yet all I hear from certain people is that “emissions regulations are ruining everything!”
I mean, sure, I’m not going to pretend there aren’t certain reliability issues from these things. But it’s clear to me that part of that is because these brands would far rather tout spec sheet numbers rather than work on improving reliability and repairability. And most buyers would far rather live with these reliability issues than dare go back to what the diesel world was like 30+ years ago.
I would say there is still a large market that would buy the original 2001 duramax if they still could. Fleets especially are burned out on this pissing contest that doesn’t serve their bottom line.
You can still get crate LB7s. You can still get used trucks. Nothing is stopping fleets from running the older stuff.
crates and old trucks are for enthusiasts, not fleets. Fleets don’t want to deal with that crap.
There is a massive disconnect between the commercial medium and heavy duty market and the pickup markets. Commercial trucks are about cost per mile, uptime, and reliability. The pickup market is all about spec sheet racing.
Curious if the commercial version of the B6.9L would sell today in a pickup with the 250 hp / 600 lb-ft / 250K mile warranty or if people would still go for the overstressed HO version.
If I had need for one of these trucks and I did a lot of miles, I’d likely get the commercial tune done to it after the fact.
RECESSION INDICATOR RED ALERT
Yes, GM especially has a certain skill at releasing crazy new products just before recessions. H3 and 2009 rings a bell.
I feel like the 8.1L gas engine came out right before the big housing crash.
That’s actually when it was discontinued. It came out for MY2001.
That makes sense, and it probably explains why my used 2500 Avalanche was such a good deal! 37 gallon tank, $4+ per gallon back in 2009/2010. Filling the tank was a serious financial decision for me back then!
That $4.25 in 2009 is now $7 a gallon after inflation.
People fail to realize that gas being so expensive isn’t just because it’s more… It’s because our dollar is also worth LESS.