Customer Corner : Mack Trucks - Bulldog On A Cummins Leash

Mack loves to sell you a myth. Big chrome bulldog on the bonnet, blue-collar grit in the adverts, heritage shots of soot, sweat and Pennsylvania steel. Built like a Mack Truck. Unbreakable. Honest. Hard working.

Strip that paint and you are not looking at a folk hero. You are looking at a mid-tier cog in a dirty machine. Recalls by the thousand. Workers marched in and out like replaceable parts. A historic emissions cheat that landed them in a billion dollar settlement club.

And bolted right into the chassis of all that is a very familiar name. Cummins.

For decades Mack has mixed its own engines with Cummins power, and in 2025 it is still promoting the Cummins L9N natural gas engine as a factory option in its trucks for the waste industry. Mack does not have to own Cummins stock to be part of the ecosystem. It just has to keep buying the hardware, building the cabs around it and sending the resulting rigs out to idle next to your kid’s school.

That alone would be bad enough. When you set it alongside Mack’s labour record, safety failures and environmental history, the partnership starts to feel almost too on brand. Cummins, a company now holding the biggest Clean Air Act civil penalty in history for its own emissions cheating, could not ask for a more apt customer.

This is not an obituary. It is a character witness statement for the prosecution.

Bulldog, Meet Leash – How Deep The Cummins Link Runs

Mack’s PR will happily talk your ear off about “legendary” MP engines and integrated powertrains. What it is quieter about is the long, very real relationship with Cummins.

Back in the late 1990s, Mack announced it would start offering Cummins engines alongside its own powerplants in certain over the road models, a move trumpeted at the time as a way to boost sales and give fleets more choice on spec. That choice was not theoretical. It showed up on order sheets and in the real world.

Fast forward to now and the names have changed but the dependence has not. Mack’s own site proudly pushes the Cummins L9N natural gas engine as a factory option on its refuse and vocational platforms, pitched to the waste industry as a “lighter weight” configuration with “near zero” emissions. Sales material talks about integrating Cummins engines with Allison transmissions for CNG powered Mack chassis. Industry guides and dealer pages list Cummins among the engine options available on Mack trucks for years.

None of this means Mack is some secret Cummins subsidiary. It means something simpler and more depressing. Cummins builds the beating heart. Mack builds the body and sells the fantasy. The money flows back up the Cummins chain either way.

When Cummins gets dragged through the courts for illegal emissions systems, every truck builder carrying those badges is part of the story, whether they like it or not. Mack has chosen to stay in that orbit.

Built Like A Mack, Treated Like A Temp

Mack likes to say the trucks are “built in the Lehigh Valley by the men and women of Mack Trucks”. Truth, with an asterisk. The same men and women keep finding out that loyalty is strictly one way.

In October 2023 about 4,000 United Auto Workers members at Mack rejected a tentative agreement by an overwhelming margin and walked out. Plants in Pennsylvania, Maryland and Florida shut down while workers demanded better wages, benefits and job protections. Management had been busy talking up a nine figure investment in facilities. Workers were busy pointing out that “investment” does not mean much if your body is finished at 55 and you are still staring at a shit pension and a corporate health plan set up to fight every serious claim.

The strike lasted weeks. Only when the pressure bit did Mack come back with a sweetened deal and a five year contract including significant wage increases. Even then, a lot of people voted yes with their teeth gritted. They had seen the playbook too many times.

By 2025 the axe swung again. Hundreds of jobs at the Macungie plant were cut as demand softened. Official language talked about “market conditions” and “aligning production”. Union voices were blunter. This is what it looks like when a multinational parent protects margins. You move work to lower cost locations, including Mexico, and you treat every round of layoffs as another line item in a quarterly slide deck.

None of that is technically illegal. That is the point. If you are in the cab welding line or on the paint robots you can give Mack your back, your lungs and your weekends. The second a forecast goes the wrong way, you are ballast.

Safety Recalls – When The Truck Fights Back

If Mack’s only sin was the way it treats its own people, that would be bad enough. But there is a second category of human being they play fast and loose with. The ones driving the trucks. The ones sharing the road with them.

In the last few years Mack has produced a steady stream of recall notices that read like a horror anthology for anyone who works behind a wheel.

Nearly 9,000 Granite trucks built for the 2024 and 2025 model years had to be recalled because LED headlights could flicker or fail outright. Lose your lights at night or in heavy weather and you are not just non compliant with a standard. You are blind in 40 tonnes of steel.

Joint recalls with Volvo have covered tens of thousands of trucks for faulty lighting control modules, meaning marker lights and headlamps can go out without warning. Other campaigns have hit brake systems and steering components, with regulators explicitly warning of increased crash risk.

Then there are the in cab safety systems that are supposed to save your life and may do the opposite. Federal summaries in 2025 flagged almost 16,000 Mack trucks with seat belt anchor problems. In a rollover, the belt may not hold. Some Mack models with RollTek seats have been recalled because the system designed to protect the driver in a crash might not deploy correctly.

You can dress that up in as many “out of an abundance of caution” phrases as you want. The reality is simple. If the wrong weld fails or the wrong sensor glitches, a driver who did everything right can end up dead for someone else’s mistake.

Allegedly it is just engineering noise, the inevitable friction in a modern product. Look at the pattern and it starts to smell like something else. Squeeze suppliers, squeeze timelines, squeeze cost. Hope nothing important breaks, and when it does, write a recall notice and move on.

The Emissions Rap Sheet

If you know anything about TCAP you already know where this is going. A company in the Cummins orbit with a long history of diesel engines and legal problems around emissions. We have seen this film before.

Back in the late 1990s, Mack was one of several engine manufacturers sued by the US Justice Department and Environmental Protection Agency for using “defeat devices” in heavy duty diesel engines. The allegation was simple. Engine controls could pass the test cycle then turn off or dial back emissions systems in real world driving. Result – nitrogen oxides spewing at levels far above legal limits while the paperwork said everything was fine.

The enforcement actions culminated in a series of settlements worth around a billion dollars across the industry, with consent decrees intended to prevent an estimated 75 million tons of NOx from ever hitting the air. Mack Trucks was not some innocent bystander. It was in the dock. It paid.

California’s air board has its own settlement history with Mack over engines that did not meet emission standards, including voluntary recall programmes to try and drag non compliant models back into line.

None of this is ancient history in climate terms. The people who breathed that exhaust are still alive. The asthma, heart disease and chronic lung problems sit in bodies that never saw a dollar of those settlements.

So when Mack now wraps itself in “near zero” rhetoric and hypes natural gas packages on Cummins power, forgive us if we do not throw confetti. You do not get to cheat, pay, pivot and carry on sacrificing other people’s air on the altar of uptime and still call yourself a responsible manufacturer with a straight face.

Perfect Customer For A Repeat Offender

If you wanted to design a customer tailor made for Cummins in 2025, it would look a lot like Mack.

Cummins has just taken a record beating for its own emissions behaviour. In late 2023 and early 2024 the company agreed to pay a $1.675 billion civil penalty in the United States for violations of the Clean Air Act tied to hundreds of thousands of Ram pickup trucks. Prosecutors described illegal defeat devices. Regulators talked about up to 960,000 vehicles affected across multiple model years. At least 600,000 trucks are set for recall and repair. The combined federal and state deal is the largest civil penalty ever under the law and one of the largest environmental penalties of any kind.

EPA summaries talk about increased nitrogen oxide emissions, with knock on impacts on smog, respiratory disease and premature death. Cummins, of course, denies intentional wrongdoing in the classic corporate way, settles without admitting liability, and declares itself “ready to move forward”.

Allegedly this is about a few bad software decisions in a very complex technical environment. Look at the long pattern of enforcement actions involving Cummins products, and it reads more like a business model – push the limits, bank the profits, argue about the tests later.

Into that swirl walks Mack, long time user of Cummins engines, current promoter of Cummins natural gas powertrain options in its own trucks. When Cummins needs volume for its packages in sectors like refuse and regional haul, customers like Mack are the channel. When Mack needs a way to look “cleaner” without sacrificing payload or uptime, Cummins is right there with a brochure.

This is why TCAP exists. To show that what looks like a hundred separate scandals is really a network. Suppliers, customers, investors and regulators all tugging on the same toxic rope. Mack and Cummins are not random points on the map. They are partners in keeping combustion on life support and calling it innovation.

White Collars Walk, Everyone Else Pays

Here is the part that should make you incandescent.

When a driver misses a pre trip check and something fails, they get blamed. When a fitter mis torques a bolt and a steering component comes loose, they get blamed. When a production worker misses a crack in a weld, they get blamed. Disciplinary, dismissal, sometimes criminal charges. Their lives shrink down to one mistake.

When a company like Mack signs off on an engine calibration that cheats a test, it pays a fine and issues a statement about its “commitment to the environment”. When a company like Cummins signs off on software that regulators say is illegal, it pays a bigger fine and does an investor call about “turning the page”. When cost cutting and rushed programmes allegedly contribute to faulty seat belts, dodgy lights or brake issues, nobody who signed the budget goes to jail.

They keep the houses, the stock, the careers. The worst that usually happens is a sideways move to another firm with the same logo in a different colour.

This is the obscenity at the heart of the bulldog myth. The people who build, drive and service the trucks take the actual risks. The people who design the product strategy, pick the suppliers and decide how much testing can be cut to hit a launch date take the bonus.

If Mack’s board had to spend one year living on the wages of a laid off Macungie assembler, driving a Granite with a recall notice in the glove box, dragging on a Ventolin inhaler between shifts, we might see a different risk appetite. Instead they sit behind conference tables and talk about “headwinds”.

Fuck that.

Why TCAP Gives A Shit

TCAP’s core target is Cummins, but you cannot understand Cummins without mapping the ecosystem that keeps paying its invoices. Mack is part of that picture.

Every time a municipal fleet opts for a Mack with a Cummins option because it ticks a procurement box, it is more money into a system that has repeatedly been caught poisoning the air and then spinning its way out of real accountability. Every time a worker on a Mack line gets told to be “flexible” while jobs leak to lower cost plants, it is the human cost of a business model that sees labour as sacrificial and fines as overheads.

You do not have to boycott every truck with a bulldog on the front. You do not have to memorise consent decrees. But you should at least know that the brand built on toughness has a long history of folding the second it is asked to choose between people and profit.

Mack is not some innocent mutt. It is a bulldog on a Cummins leash, and it bites in exactly one direction. Downwards.

TCAP will keep naming that for what it is.

Lee Thompson – Founder, The Cummins Accountability Project

Customer Corner : Mack Trucks – Bulldog On A Cummins Leash