Some folks out there on the ‘Net have reported that GM is planning to develop a new 8.3L Duramax turbodiesel engine for use in its various truck models, citing unnamed insider sources. Looking over the rumors, though, there are a few problems. Here’s why we think the rumors are off-base.
For starters, if GM really was developing a new 8.3L Duramax engine, it wouldn’t go under the hood of The General’s light-duty 1500 truck models. Rather, an engine like that would be better suited for something bigger, like GM’s HD pickups, so the rumors should be evaluated with that in mind.
Right off the bat, though, the bigger-is-better bragging rights mentality of a new 8.3L Duramax engine doesn’t seem to fit GM’s strategy or direction.
“Chasing the highest power and torque figures for the sake of having the highest numbers in the segment doesn’t seem to be GM’s focus in the current T1- and prior K2-generation of its heavy duty trucks,” says GM Authority Executive Editor Alex Luft. “Instead, today’s GM is more focused on delivering the power and torque levels that are useful and balanced for the specific vehicle application, not so much for the purpose of bragging rights. Rather, bragging rights seem to be more Ford’s focus.”
There are deeper issues, as well. For example, even if GM did offer a new monster diesel in its HD pickup trucks, what would it enable the truck to do that it couldn’t do with the current engine lineup?
“The towing and hauling ratings for GM’s current HD models (max 36,000 pounds with a fifth wheel / gooseneck) are not limited by engine output so much as they are by vehicle chassis / platform limitations,” Luft explains. “So, even with more power and torque than the updated L5P currently produces, towing and hauling capacities would not be improved without significant upgrades to other parts of the truck.”
What’s more, at 36,000 pounds, the current setup is hugely capable as it is. Going beyond that would likely be better suited for an entirely different vehicle, such as a Class 7.
“Towing close to the max on any truck doesn’t feel all that great, and to that end, this rumored 8.3L Duramax wouldn’t exactly enhance the experience,” Luft says.
Furthermore, more power and torque can still be achieved without a brand-new 8.3L engine. If GM wanted more more output, the aftermarket has proven that the L5P is capable of far more than the current factory ratings of 470 horsepower and 975 pound-feet of torque, so why not upgrade the L5P, rather than develop a whole new engine?
One possibility is that this rumored 8.3L Duramax could find a home in GM’s MD trucks, but even that seems highly unlikely given the MD lineup’s relatively low volume. Instead, the MD line offers variants of the HD lineup’s powerplants, rather than an entirely unique engine developed specifically for the MD trucks.
“The bottom line is this – an 8.3L Duramax engine doesn’t make sense at all for GM or for its HD trucks, current or next generation,” Luft says.
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Comments
But come on, still would be sick. Then they could bring back the Kodiak
Already exists as the Silverado Medium Duty.
Yup, just some investors talking smack to get all those “I gotta have the biggest coal roller” peckers hard so they can judge the interest in 8.3’s ,then call Mary and tell’r yay or nay on what to do..
Doubtful under the current regime.
Be easy to do. Take the current LP5, replace the aluminum pistons with short side steelies, stroke that crankshaft out to a square bore/stroke ratio, bjfgger turbo and done.
I personally think they should dump that snail for a set of screws. Banks power lockjaw truck shows how potent a half@@sed screw charged truck is. 650-700hp is totally possible with the LP5
i mean if mary wants to get HD diesel to 210k msrp that would be one way of doing it……………..
I wonder how such a large engine would even be packaged without the whole truck getting strangely weird and super heavy, killing towing and hauling in the process. I call BS, unless this is for a much larger (Class 7-8) truck…
Same size as the current Duramax 6.6 liter. Just take advantage of the new CGI with a little bigger bore and add some stroke. GM is bored by the other two taking the lead. Bring it now.
I hope if this is true,That GM will do 8.3Liter inline 6 duramax with the 10 speed Allison.
Curious if the rumor was actually a 8.3 gasser from that source.
8.3 gas would be nice.
MaryJoe would never approve this. Unless it is for the MD 4500-6500 trucks.
I figured, though it would be interesting and maybe a wise investment for GM to get into the commercial truck engine segment again (they used to own Detroit Diesel), it is so overpacked with competitors that regulations keep these engines pretty much the same from each manufacturer in terms of performance capability, so you might as well get the one that has the best reliability/easiest to service. I am curious where this rumor started, I saw it on TFL first and have tried looking it up, nothing outside of TFL. It is unusual for them to post something like this with no real proof or source to back it up.
They should do it. GM used to be about the BEST….whether that was styling, riding/driving/handling, HP/TQ numbers………Now, since Ol Mary has taken over. They are happy staying behind Ford and Dodge….SMH
If true it’s for medium duty and probably a joint deal with Navistar to help with the volume issue mentioned by GMA. Navistar has publicly said they are done developing combustion engines, their medium line is powered exclusively by Cummins. An advantageous deal with GM might help their margins a little bit. I still don’t think the rumor is true, I think it came from Fast Lane and they are losers. But if it is true I think that would be the only way
Unless its for emissions reasons so they don’t get caught and fined like cummins did, I would expect the 8.3L is an updated versions of the old 496 8.1L gas to put ford’s “godzilla” in it’s place.
PEOPLE FORGET THAT GM VERY HEAVY TRUCKS, 6500 & 7500 MODELS SHARED A 7.8 LITER DIESEL WITH IZUZZU TRUCKS.
SINCE THERE WAS A SERIOUS DESIGN FLAW WITH THE OLD TECH 6.6 LITER DIESEL WITH A BREAKOFF PIN ON THE CRANKSHAFT, THIS CRANKSHAFT PIN IS A STUPID DESIGN.
IT’S POSSIBLE THAT GM WILL DESIGN A MUCH BETTER DIESEL AND SHARE IT WITH OTHER COMPANIES. THEY CAN USE THE NEW DESIGN TO ALSO MAKE A DOWNSIZE NEW 6.6 LITER V8 DIESEL OR A SMALL V6 DIESEL. AS LONG AS GM SELLS THE BIG 8.3 LITER TO INDUSTRY, FOR INDUSTRIAL PURPOSES, IT WILL JUSTIFY THE HUGE EXPENSE OF DEVELOPING IT. GM MIGHT WORK WITH TOYOTA ON IT, AS THEY ARE DEVELOPING OTHER STUFF TOGETHER. TOYOTA SELLS AROUND THE WORLD, SO SALES AND PARTS DISTRIBUTION IS ALREADY THERE. THIS WILL BENEFIT GM TO EXPAND IT’S INDUSTRIAL BASE WORLDWIDE.
ANOTHER THOUGHT, SUPPOSE GM WANTS TO START SELLING A NEW 8500 SERIES TRUCK VERSION, THIS WILL JUSTIFY THE EXPENSE. THE DOWNTURN IN EV DEMAND & SALES MEANS GM NEEDS A NEW SPOT TO GET PROFITS BACK AND A CLASS 7 & CLASS 8 TRUCK, IS THE WAY TO DO IT. THE NEW 8.3 BLOCK AND HEADS CAN ALSO BE USED FOR A HIGH CUBE CNG ENGINE FOR INDUSTRIAL PURPOSES. SMALL, LESS THAN 20 LITER ELECTRIC POWER PLANTS RUNNING ON CNG ARE IN DEMAND FOR TOWNS AND INDUSTRIAL PARKS AROUND THE WORLD.
Ai POWER DEMAND WILL OVERWHELM BIG U.S. CITIES IN 2024 & 2025. Ai DEMAND FOR HUGE POWER, MEANS THAT BIG CITIES LIKE NY WILL REQUIRE AT LEAST 2 NUKE MORE POWER PLANTS. A NUMBER OF CNG FUELED POWER PLANTS CAN BE INSTALLED QUICKLY & BILLIONS CHEAPER THAN A SMALL NUCLEAR POWER PLANT. ANY MEDIUM SIZE CITY THAT OFFERS ENOUGH ELECTRIC POWER TO AVOID BROWNOUTS AND BLACKOUTS WILL ATTRACT BOTH INDUSTRY AND PRIVATE HOME DEVELOPMENTS.
REMEMBER THAT ALL DIESEL PROBLEMS ARE EMISSIONS ISSUES. CATEPILLAR STOPPED SELLING HD DIESEL ENGINES IN CLASS 8 TRUCKS BECAUSE THEY DIDN’T WANT TO SPEND THE BILLIONS TO PASS FUTURE EMISSIONS REGULATIONS.
THINK OUTSIDE THE BOX. MARY BARRA NEEDS TO FIND A WAY OUT OF THE EV FIASCO. THIS WILL DO IT.
ANOTHER GOOD REASON THAT GM SHOULD BUILD A NEW DESIGN LARGE 8.3 LITER DIESELIS THAT IT CAN BE DESIGNED
TO AVOID USING EXPENSIVE DPF FLUID TO MEET SURPASS FUTURE EMISSISION REGULATIONS. A DIESEL ENGINE RUNNING WITH A PROPANE LPG BOOST SYSTEM WILL ALLOW THE ENGINE TO RUN MUCH CLEANER AND GEET A HUGE BOOST IN MPG.. EMISSIONS WITH A PROPANE BOOST SYSTEM ON MEDIUM SIZE 7 LITER AND LARGER 11 AND 13 LITER DIESEL ENGINES DROP BY 90 PERCENT. IT IS NOT NEW TECHNOLOGY.
PROPANE WORKS AS A BOOST FIR A DIESEL ENGINE IS BECAUSE IT HAS A HUGE 36 TO 37 PERCENT HYDROGEN CONTENT. PROPANE IS ALSO CHEAPER THAN DPF FLUID. A PROPANE BOOST SYSTEM ON LARGE 11 AND 13 LITER DETROIT DIESEL ENGINES HAS BEEN USED FOR MANY YEARS.
OWNER OPERATORS WHO HAVE USED IT REPORT FUEL SAVINGS OF 25 TO 30 PERCENT IN MPG AND AN INCREASE IN TORQUE AND HP. PROPANE FUEL STATIONS ARE READILY AVAILABLE AROUND NORTH AMERICA. RUNNING ON 5 TO 10 PERCENT PROPANE WILL ALMOST ELIMINATE THE NEED FOR A REGEN TO KICK IN, REDUCING DIESEL FUEL DEMAND AND COSTS FOR THE OPERATOR, BE IT AN OWNER OPERATOR OR A FLEET OR MUNICIPLITY.
PROPANE IS ALSO LIGHTER THAN DIESEL AS IT ONLY WEIGHS ONLY 4.3 POUNDS PER GALLON, WHICH IS 2/3 OF THE WEIGHT OF DIESEL FUEL.
Why are you shouting?
The DEF fluid scheme is a nothing more than a total scam anyway, to make the greenies feel good about themselves!
Good God calm down Boomer
Don’t need a bigger diesel. A bigger gas motor to compete with the Godzilla might be nice, though.
Again.. GM guys always thinking bigger is better🤣🤣Ford has proven you can do more with less
Ya ford is doing so great with the 6.7L eating cams at 130k resulting in a $30K repair replacing the engine! Ford is straight up garbage! I own an independent shop and the majority of my business is working on these over engendered pieces of trash! Delete the L5P it will do circles around the ford and at the end of the day make ford suck on its huge balls! Sorry ford guys just telling you how it is! L5P will outperform in every way over fords stupid design!
Why not do both? Increase the power on the l5p and create the 8.3l. The 8.3 probably won’t be budget friendly. Maybe buy one used later down the road. Would be very interesting to see in the duramax truck lineup!
I want it to be true, but unless the leak came directly from someone within the Duramax engine program I’m not going to hold my breath. That said unlike gmauthority I can see a practical case for the 8.3 Duramax. A modern big displacement engine will have built in emissions and reliability advantages.
How cool would it be to have a 6.6 and 8.3 option for (both) gas and diesel HD trucks. This move would put GM in a very desirable position within the HD segment.
The fact that the current 6.6L engine is capable of making more power with aftermarket parts is irrelevant for comparison to a production engine with emissions requirements, a warranty, durability expectations, and cost targets.
You’re missing the point here, I think.
The fact that the aftermarket can squeeze more power from the current 6.6L to me is just an example of what’s possible with the engine. The factory can usually do all this better, faster and cheaper. There is headroom in the 6.6 and it would not be strung out to impact the areas of concerns (emissions, warranty, durability or cost).
Unlike some motor magazines and tube videos, I don’t need the fastest truck up the hill.
What I DO need is to pull that trailer up that hill, six days a week, for years, and not have it bankrupt me in maintenance!
Yes the 6.6 has had a lot of potential, but somewhere there’s going to be a ceiling in performance vs longevity for the cube size.
Make sure it’s got a durable injection pump. That’s the ticket
No replacement for displacement! Go big or go home! ….and get rid of that def fluid while you’re at it!
I think it’s %100 ludicrous to tow 5x more than what the truck weighs ! Its just not safe !
How is it not safe? A class 8 tractor tows 5x what it weighs with a semi-trailer. It’s not really any different than a heavy-duty pickup with a 5th wheel. As long as the brakes and the driver are up to the task, it’s fine.
Just bring back the 8.1L with a redesign and fuel efficiency. It was already a great motor to start with.
Love my 8.1 with 232,000 miles. I’d buy an 8.3 gas or diesel in a heartbeat.
They are shoving these EV crap down our throats even though nobody wants them all about control and OL Mary is got GM on the road to destruction she was put in place to do the bidding of Oblama. The previous CEO Was condemned for getting a million dollar bonus but look at how much she hauls in to destroy a great American Company
“she was put in place to do the bidding of Oblama”
Really? That’s one of the most ridiculous things that I’ve ever heard.
They are shoving these EV crap down our throats even though nobody wants them all about control and OL Mary is got GM on the road to destruction she was put in place to do the bidding of Oblama. The previous CEO Was condemned for getting a million dollar bonus but look at how much she hauls in to destroy a great American Company. Let spray raw diesel fuel into the exhaust to fight NOX when pine trees emit NOX also and what does spraying pig piss (Amonia) doing to the air in the long run? anybody?
Let spray raw diesel fuel into the exhaust to fight NOX when pine trees emit NOX also and what does spraying pig piss (Amonia) doing to the air in the long run? anybody?
Uh, doesn’t the EPA have a 6.7 liter limit on diesel engines for light duty trucks?
Please elaborate.
duramax go vroom
Dyslexia = 3.8L
Oof, GM has always thought bigger is better, they couldn’t outdo the V10 with a 8.1liter V8 how do they think they are going to outdo Ford which has the best in class everything..HP, tq, towing etc…
It would be nice if the big 3 would concentrate on making their products more reliable. They are plenty powerful for the size truck. The problem is the emissions and the dreaded limp mode. The cost of maintaining and fixing is 100 times the cost of the pre emissions. There is no comparing the reliability of the pre emission diesels. The only time an old diesel seen a tow truck is if you wrecked it!
You can thank the overbearing and unrealistic gumbemt trds for their ignorance and arrogance when it comes to physics, reality and the environmental impact their mandates are really having on this planet.
Who said the 8.3L would go into the 1500 series? That would be a silly assumption, berthed suspension alone couldn’t handle that engine and a medium load.
Regardless, I could definitely see this as an option, but not a standard engine in the 2500/3500. GM is all about making money and I can see people paying for this option.
The author has a typical GM mindset. “MEDIOCRITY is best.”
what? the current 6.6 doesn’t come in a 1500 Silverado either
Why not just electrically power it with a permanent trailer full of batteries and bed full of batteries with solar paneled roofs that can tow another trailer in tandem at 45k pounds? (Sarcasm)
I wonder if they are doing it to lower temps to help with NOX. Chasing emissions with the same output.
Personally GM has a class A appearance, but beyond that they need to do their homework because of everything mechanical. Nothing is right. I own a Chevy one of the sharpest trucks on the highway, other than that they are weak and I say this from having owned other trucks. My new Chevy is sitting at the dealership now because the transmission has went out. I’ve me mechanical issues over and over then have to wait 6-8 weeks for parts etc. I’m a Chevy man but I have to say they have to improve or they are going to fail way behind in sales , everything….
No sign of the MegaMax still after some 45 days after the TFL-scoop? Must be a lot of people involved in this project if it`s real.
One word: EMISSIONS
Also: RELIABILITY
Current engines across the Big 3 are pretty high strung. The power outputs of the Cummins and Ford 6.7s and the GM 6.6 are good, but are a problem for emissions with very high cylinder pressure. If GM can build an 8.3 engine, the have the ability to lower cylinder pressure for the next generation of NOx emissions regulations that will kick in sometime around 2027.
Only realistic reason to increase displacement is to meet emissions. A larger displacement could be detuned so it might run with lower combustion temperatures and naturally produce less NOx, and still match current power levels of the 6.6.
Just a thought, there seems to be no other reason to engineer a larger engine with the extreme emission standards coming in ‘27. The 2500/3500 don’t need more power, but they do need an engine that can continue to meet EPA standards without sacrificing power. I think bigger displacement will give the engineers a bigger power range to tune the emission output
None of you F*ckers have s clue… I would say chevy is the only one that does but it’s obvious they ride by the back of their pants and fence.. watching ford to see what they do.
Yeah Dave that’s why Ford did such a great job with that 6.0 Diesel right
Find my comment and read it I’m a die-hard Chevy guy but I also happen to own one of those so-called 6.0 you’re talking about and let’s just say the 6.0 has given me more trouble-free miles and that’s to not say that they’re not without a little bit of high maintenance but more trouble-free miles than all three of my duramax’s combined….
When people bring up this 8.3L rumor, they always leave out the context that it was at the same time as the rumor about GM bringing back the 6500-8500 size trucks. That size engine makes since in that size of truck. So “IF” GM is going to release an 8.3L engine, it will be for a heavy duty market truck. Maybe just maybe they would but a 8.3L in the 4500 and 5500. But definitely not the 2500 and 3500… And this article even mentions the 1500 which in my opinion is just plain dumb to even think about.
Um… Didn’t this rumour start around the first of April?
I love the idea of making a new massive 8.3 duramax would be cool but probably wight a absolute ton.I think they should put more effort into the frame and drivetrain first before doing something like this with 2500 or 3500 but it could make more sense in the big 4500 and 5500 and 6500
Gas 8.3. I’ll buy one. Nick.
Finally blow the Doors off Ford And Dodge. Cummins. Pull that junk around the block. Give me a 8.3 in a 4500 Dually. With a 11 ft Service box. Go make some Money. Thanks Lenny
This is confirmed from the Milford proving grounds itself, this article is obviously outdated and doesn’t under this isn’t about power.. it’s about emissions.
Bigger engine with lower compression means more power plus lower cylinder temps and less NOx
A 8.3 in line 6 cyl oil burner would be the king with a large turbo or better yet a Blower. Easy to maintain all around big dady to the 3.0 it should go into the larger trucks just because it makes sense, period. Geterdone ! Blow all the rest out of the water with a million mile engine .
Maybe it doesn’t matter to the executive, but it does matter to the consumer! A powerful and powerful engine does matter! When a customer going to a dealership to buy a HD vehicle, it’s because he’s going to use it to move heavy things! And in that sense, Ford and Ram are ahead. So don’t come and tell them that they don’t need to make a more powerful engine. It doesn’t matter if it’s an 8.2 cylinder, or if they want to adjust the current 6.6. What matters here is that they update it so they can get back to the competition.