Turbo upgrades on newer diesels come with a question that barely existed a decade ago: will this keep my truck legal? For 2019–2024 6.7 Cummins owners the answer matters more than ever, because enforcement against emissions-defeat modifications has tightened sharply since 2020. The good news is that a properly chosen variable-geometry drop-in lets you add real airflow and towing capability while keeping every factory emissions system in place.

The post-2020 landscape

Beginning around 2020, the US EPA and California's CARB stepped up enforcement against "delete" tuning and hardware that removes or disables emissions equipment — targeting manufacturers, installers, and sellers of defeat devices. Canada regulates tampering federally as well, and provincial inspection regimes vary. The practical takeaway is the same on both sides of the border: modifications that remove the DPF, DEF/SCR, or EGR are not road-legal, and the compliance risk now sits with everyone in the chain, not just the truck owner.

Why a VGT drop-in is the compliant path

A variable-geometry drop-in like the TNT HE300VG 63mm replaces the factory turbo with a higher-airflow unit while keeping the DPF, DEF/SCR, and EGR systems fully intact and functional. You get the benefits owners actually want — lower EGTs, faster spool, more towing headroom — without stepping outside emissions-legal territory. It also retains the factory exhaust brake, so nothing about the truck's emissions or safety behaviour is compromised.

This mirrors how we frame upgrades across the whole catalogue; for the broader Canada-vs-US picture, see Emissions-Legal Diesel Turbo Upgrades in Canada.

Canada vs US, briefly

• Canada: Federal law prohibits tampering with emissions systems; several provinces run inspection or anti-tampering programs. Keeping the factory systems intact keeps you onside.
• US: The Clean Air Act prohibits defeat devices; EPA and CARB enforcement has produced significant penalties since 2020. Emissions-intact upgrades avoid the issue entirely.

We're a turbo maker, not your compliance officer — always confirm the rules that apply where you live and register the truck. But the design principle is simple: keep the emissions equipment, and a turbo upgrade stays legal.

Pair it with legal supporting changes

Airflow and EGT control come from more than the turbo. Emissions-legal supporting changes — intake, intercooler, monitoring — are covered in Supporting Mods for Towing & Power and How to Lower EGTs on a 6.7 Cummins.

Frequently asked questions

Is a turbo upgrade legal on a 2019–2024 6.7 Cummins?

Yes, when it retains the factory emissions systems. A VGT drop-in that keeps the DPF, DEF/SCR, and EGR intact is road-legal; removing those systems is not.

Does the TNT HE300VG require deleting emissions equipment?

No. It's a direct replacement that retains the factory DPF, DEF/SCR, EGR, and exhaust brake.

What changed after 2020?

EPA and CARB significantly increased enforcement against defeat devices and delete tuning, with penalties extending to sellers and installers, not just owners.

Is the rule different in Canada?

The specifics differ, but the principle is the same — keep the emissions systems intact and the upgrade stays legal. Confirm your provincial requirements.