GM said they crushed them all. One ended up in Sweden

The Duramax is General Motors’ diesel engine family, best known today for modern V8 and I6 applications in trucks. Here, the hosts are talking about an earlier, unreleased Duramax concept: a 4.5-liter turbo diesel V8 that was codenamed LMK.

A turbo diesel V8 is a diesel engine with eight cylinders that uses a turbocharger to force more air into the cylinders. That extra air lets the engine burn more fuel efficiently, which can raise torque and improve real-world pulling power.

LMK is the codename for GM’s unreleased 4.5-liter Duramax turbo-diesel V8 program. Codenames like this are internal project labels used during development, and they often disappear once a program is canceled.

When an automaker says a development program “fell apart,” it usually means the project was canceled or re-scoped due to cost, timing, or shifting corporate priorities. In this case, the hosts connect it to the 2008 economic collapse and bankruptcy.

The 2008 economic collapse triggered major funding and demand problems across the auto industry. For GM, it led to bankruptcy, which in turn killed the LMK Duramax engine program before it could enter production.

Filing for bankruptcy is a legal process companies use when they can’t meet financial obligations. For GM, it meant major restructuring and cancellations, including taking the LMK 4.5-liter Duramax down with it.

Prototypes are early, experimental versions of a product—here, likely engine builds—used to test whether the design works in the real world. The segment claims some prototypes escaped destruction even though GM said they were all crushed.

This segment centers on the mystery of an unreleased Duramax diesel program showing up outside the factory. The hosts discuss how photos and new information surfaced, implying surviving prototypes rather than a fully destroyed development effort.

The Chevrolet Silverado EV is an electric pickup, and the “Trail Boss” trim is tuned for off-road use. In this segment, the host highlights its massive battery pack and heavy weight, which help explain why it feels so forceful off the line.

“Pound-feet” (lb-ft) is a unit for torque, measuring how much twisting force the powertrain can apply. The host is using this number to emphasize how the Silverado EV’s electric motor output translates into strong real-world acceleration.

When off-roaders say “35,” they’re usually referring to 35-inch tires. Tire size affects ground clearance, ride feel, and how well the truck can roll over obstacles.

“Rolling oxymoron” is a rhetorical way to describe something that seems contradictory but exists anyway. Here it’s used to frame an electric truck as an off-road machine—two ideas that traditionally didn’t go together.

“Half-ton” is a common pickup-truck class label that roughly corresponds to the truck’s payload rating tradition (not a literal half-ton of weight). The hosts use it to frame the competitive target market for GM’s new diesel engine project.

The Dodge Ram is a full-size pickup truck known for being a major player in the “big three” truck conversation. The podcast reference to “those days” suggests it’s being used to frame how truck lineups and reputations have evolved over time. Ram often comes up in discussions about what buyers wanted from large trucks—work capability, power, and practicality.

“Small block” refers to GM’s compact V8 engine architecture, and “gas V8s” means gasoline versions of those engines. The segment contrasts them with the diesel engine’s goals—better fuel economy and much higher torque output for the same truck class.

A “hot V turbocharger” places the turbocharger inside the V-shaped valley of a V-engine, right where exhaust ports are located. This shortens the path exhaust gases travel to the turbo, which can improve response and reduce turbo lag compared with setups where the turbo sits farther away.

The Cadillac CT6V Blackwing is a high-performance sedan from Cadillac that’s known for its serious powertrain and track-capable attitude. In this segment, it’s used as a reference point for the “hot V” turbocharger layout, linking the diesel engine discussion to a recognizable performance application.

The Mercedes-AMG GT is a performance sports car line from Mercedes-AMG, famous for its strong engines and turbocharged layouts. In this segment, it’s referenced as an example of where a “hot V turbocharger” configuration can be found, helping listeners connect the diesel engine’s design to a familiar gasoline performance platform.

Torque is the twisting force an engine produces, and it’s especially important for diesel engines because it helps the vehicle accelerate and tow strongly at lower engine speeds. When the host says the torque number is “unmatched,” they mean the peak twisting force figure was extremely high compared with other light-duty diesels.

Chapter 11 bankruptcy is a legal process where a company reorganizes its debts and operations rather than immediately liquidating. In this context, the host is saying GM’s Chapter 11 restructuring derailed the engine’s development and limited what people could learn or verify about it.

A “hot V” setup refers to placing exhaust components close to the engine’s V-shaped cylinder bank so exhaust heat is managed differently than in a conventional layout. In practice, it’s commonly discussed in turbocharged V-engines because it can help turbo response, but it also changes thermal loading and packaging.

Duty cycle is the pattern of how a vehicle is used over time—how hard it works, how long it works, and under what conditions. Pickup trucks often have a duty cycle focused on towing and steady loads, while sports cars are used more for sustained high-speed operation and repeated high-load bursts.

A radiator cools the engine coolant by transferring heat to airflow. An intercooler cools the compressed intake air from a turbocharger; cooler air is denser, which helps the engine make more power and can reduce knock risk.

RPM (revolutions per minute) is how fast the engine’s crankshaft spins. The transcript contrasts sports-car operation at higher RPM with towing/uphill operation at lower RPM, which affects how the engine makes power and how heat is managed.

A turbocharger (“turbo”) uses exhaust gas to spin a turbine, which drives a compressor to force more air into the engine. More air lets the engine burn more fuel for more power, and it can also improve efficiency when used correctly.

“Body-on-frame” construction uses a separate ladder frame for structure, with the body mounted on top. This is common in trucks because it’s durable for towing and can better tolerate impacts and twisting loads compared with many unibody designs.

Four-wheel drive (4WD) sends power to both the front and rear axles to improve traction. It’s especially relevant for trucks because it helps manage low-grip situations like towing on grades, snow, mud, or uneven terrain.

High altitude means thinner air, which reduces the amount of oxygen available for combustion. That affects engine power and cooling strategy, so manufacturers may engineer trucks to operate reliably in those conditions.

Colorado is referenced as a testing region where manufacturers evaluate vehicles under different climate and altitude conditions. The underlying idea is that real-world durability and performance depend on how hardware behaves across temperature ranges and terrain.

Hoover Dam is a major landmark on the border of Nevada and Arizona in the U.S., and it’s referenced here as a testing location. The host’s point is that manufacturers test engines and vehicles across varied environments, including harsh desert conditions.

Gail Banks is a well-known diesel-performance specialist, often associated with turbo-diesel tuning and aftermarket development. In this segment, the host frames him as an expert whose long experience and detailed notes helped GM evaluate diesel engines for new applications.

GM (General Motors) is the automaker behind the project being discussed. Here, GM is described as inviting a diesel expert to evaluate engines and considering whether they could be adapted for marine use (like powering boats).

“Inboard outboards” is a marine configuration where the engine is mounted inboard (inside the hull) but drives a propeller through an outboard-style arrangement. The host uses it to explain why marine builders often modify car engines for boat use.

“Water cooled” means the engine uses a liquid coolant (typically a mix of water and antifreeze) to absorb heat and carry it to a radiator/heat exchanger. In marine applications, water cooling is especially common because it can be integrated with the boat’s cooling system.

“Small block” refers to Chevrolet’s compact V8 engine family, known for being widely used, modified, and adapted across different applications. In this segment, the host highlights that marine engines can be built from (or based on) these automotive small-block designs.

“Tall tales” here means exaggerated stories or rumors that spread without solid evidence. The host contrasts those kinds of auto-industry rumors with the documented evidence they later found in this engine story.

A variable-geometry turbocharger uses adjustable vanes inside the turbo to change how exhaust gas flows. That helps the turbo spool up quickly at low engine speeds and still make strong boost at higher speeds.

A “hot V” engine is a packaging/layout where the exhaust components (and often the turbo) sit inside the V-shaped valley between the cylinder banks. This can shorten exhaust path length and improve turbo response, but it also concentrates heat in the engine’s center area.

The Ram 1500 is a full-size pickup, and this segment is specifically talking about its EcoDiesel setup. “Eco diesel” refers to a diesel variant aimed at better fuel economy than traditional gas V8s, using a smaller displacement diesel.

This describes a 3.0-liter turbo diesel with an inline-six cylinder layout. Inline-six engines are known for smoothness and balanced operation, and pairing that layout with a turbo diesel setup is often about maximizing low-end torque for towing and highway cruising.

The Chevrolet Suburban is a full-size SUV, and this segment notes the diesel was offered there. Diesel in a Suburban is typically chosen for torque and efficiency on long trips, especially compared with gas V8s.

The GMC Yukon is a full-size SUV, and the segment says the diesel engine was sold in it. That matters because fitting a diesel into a large SUV is usually about delivering strong torque for highway cruising and towing.

The Chevrolet Tahoe is another full-size SUV mentioned as a place where the diesel was still sold. In this context, the point is that GM kept the diesel option alive in large vehicles rather than dropping it entirely.

The Cadillac Escalade is a luxury full-size SUV, and the segment says the diesel was offered in it but “nobody bought it.” That highlights how even a good engine can struggle if buyers prefer the brand’s typical gas V8 feel or if the diesel option isn’t compelling enough.

The GMC Sierra is a full-size pickup, and the segment says the diesel engine could still be bought in these light-duty trucks. Diesel offerings in trucks are typically about torque for towing and steady highway cruising.

The Chevrolet Silverado is a full-size pickup, and this segment places the diesel engine in the “light duty trucks” lineup. The key point is that GM kept the diesel available in mainstream truck models rather than limiting it to niche vehicles.

Cummins is a diesel-engine maker whose engines are commonly found in heavy-duty trucks. When someone says “Cummins-powered,” they mean the truck uses a Cummins diesel, which is often compared directly with other diesel options like Duramax and Powerstroke.

Powerstroke is Ford’s diesel-engine brand, commonly compared with GM’s Duramax and Ram’s Cummins. Here it’s part of the “which diesel should I buy?” debate that often comes down to engine layout and how it affects efficiency and towing behavior.

A 10-speed transmission is an automatic gearbox with ten forward gear ratios. More gears let the engine stay closer to its most efficient operating range, which can improve fuel economy—especially when paired with a diesel’s torque characteristics.

“Turbo 6” here refers to a turbocharged inline-six diesel configuration. Turbocharging forces more air into the engine, which helps it make strong torque and power while still targeting efficiency.

EPA ratings are fuel-economy estimates published by the U.S. Environmental Protection Agency based on standardized testing. The hosts use them as a benchmark for what the turbocharged inline-six can achieve in real-world conditions.

Full-size pickups are large trucks typically used for towing and hauling, with bigger engines and heavier curb weights than smaller trucks. The segment notes that these vehicles can still reach high mileage when not towing heavy trailers.

A heavy trailer increases aerodynamic drag and rolling resistance, which raises the load on the engine and transmission. That’s why fuel economy drops when towing, even if the truck is otherwise efficient.

The Ford F-150 is a full-size pickup truck known for offering multiple engine options, including diesel variants. In this segment, the host is specifically talking about a turbo-diesel setup offered in the F-150 for a short time, which affects how it feels (boost response) and how it drinks fuel.

Range Rover is Land Rover’s luxury SUV line, and in this segment it’s used as a clue for where the engine design came from. The host says the diesel engine in the Ford F-150 was essentially a Range Rover engine offered for only a couple model years, which matters because it explains why it’s rare and how it behaves.

“Spooling” describes how fast a turbocharger spins up to generate boost pressure. The host calls it the quickest-spooling factory-stock turbo diesel they’ve driven, linking that to the near-zero turbo lag they experienced.

“Factory stock” means the vehicle is in its original, unmodified configuration as delivered by the manufacturer. The host emphasizes that the turbo spooled quickly even without aftermarket upgrades, making the behavior more notable.

Super Duty is Ford’s heavy-duty truck line (bigger than the standard F-150), often associated with higher-output diesel variants. The host contrasts the earlier F-150 diesel with the “current modern Super Duty high output ones,” implying improved torque and boost behavior in newer heavy-duty applications.

Turbo lag is the delay between when you press the accelerator and when a turbocharger builds enough boost to make power. The host says the truck had “almost no turbo lag,” meaning the turbo spooled quickly and the engine felt responsive.

“EcoDiesel” is a specific diesel engine branding used by Ram for a fuel-economy-focused diesel variant. The host uses it to explain what diesel trucks are common locally and to set up the point that buyers may not realize the engine’s origin.

Duramax is GM’s diesel engine family, and the “3-liter Duramax” is a smaller-displacement diesel designed for modern efficiency while still delivering strong low-end torque. In this segment, the host highlights its updated output (495 lb-ft) as part of the argument for why diesel can work in a half-ton truck used daily.

“Torque” is the twisting force an engine makes, and it strongly affects how easily a vehicle accelerates and how well it tows. “Pound-feet” (lb-ft) is the unit used in the US to measure that twisting force. Higher torque usually means the truck can pull heavier loads more easily, especially at lower engine speeds.

“13,300 pounds” is a towing-capacity figure—how much weight the vehicle is rated to pull. Towing capacity depends on the engine’s torque, transmission gearing, cooling capability, and the vehicle’s overall hardware. It’s a practical number enthusiasts use to judge whether a truck can handle real hauling needs.

Diesel exhaust fluid (DEF) is a urea-based liquid injected into the exhaust system to reduce harmful nitrogen-oxide emissions. It’s used by modern diesel engines with selective catalytic reduction (SCR). When DEF runs low or the system can’t dose it correctly, the vehicle can limit power or trigger warning lights.

A diesel “emission system” is the set of components that reduce pollutants before they leave the tailpipe. On modern diesels, this commonly includes DEF/urea dosing plus catalysts and sensors that monitor exhaust chemistry. These systems add complexity, and issues can be more noticeable than on older engines without them.

“Hemi” refers to Chrysler’s hemispherical combustion chamber engine design, commonly associated with Dodge/Chrysler performance V8s. The key idea is that the cylinder head shape helps airflow and combustion, which can support higher power—though real-world results depend on the specific engine and tune.

“EcoBoost” is Ford’s turbocharged engine family, and the “F-150” is Ford’s best-selling full-size pickup. The host is pointing out that you can get very high torque from a turbocharged EcoBoost setup without needing a “Raptor” model.

The Ford F-150 is a full-size pickup truck that’s widely known for offering strong engine options and broad capability for work and towing. The podcast highlights torque and power in an EcoBoost F-150, emphasizing that you can get impressive performance without needing the most extreme variant. It’s discussed because the F-150 is often a benchmark for how modern turbocharged engines deliver everyday drivability.

“Hurricane” is the name used for a high-output engine family in Ram’s lineup, and “high output” indicates a more powerful calibration/variant. In this context, the host is using it to explain why the Ram 1500 can accelerate hard enough to break traction.

DPF (diesel particulate filter) traps soot particles produced by a diesel engine. It periodically burns that soot off (regeneration) to keep emissions within limits, especially under stricter particulate regulations.

EGR (exhaust gas recirculation) is a system that routes a portion of exhaust gas back into the engine’s intake. That lowers combustion temperatures and helps reduce nitrogen oxides (NOx), which are a major target of emissions regulations.

Aftertreatment systems are emissions-control devices placed after the engine, in the exhaust path. For diesels, they commonly include components like DPFs and NOx-control systems to meet regulated limits.

A Twin Turbo V6 is a V6 engine with two turbochargers, which helps deliver stronger low-end and midrange boost compared with a single-turbo setup. In trucks, that typically translates to quicker throttle response and more usable torque for towing and passing.

“Limited F-150” here refers to a short-lived, higher-performance F-150 configuration (a narrow-body “normal” F-150) that was fitted with the Raptor’s high-output engine. The point is that it wasn’t just a trim badge—it was a way to get Raptor-level power in a more standard body style.

This is Ford’s EcoBoost 3.5-liter V6 with two turbochargers (“twin-turbo”) tuned for higher output. Turbocharging forces more air into the engine, which is why the host can quote big torque numbers and describe the truck “lunging forward” under full throttle.

“Hold their value” is a shorthand for residual value—how much of the purchase price a vehicle retains over time. Limited-run, desirable powertrains can keep resale prices higher than more common versions.