If you own a 6.7 Cummins-powered truck, you’ve probably heard people talk about EGTs. High exhaust gas temperatures can become a serious issue when towing heavy loads, running performance tuning, or pushing your truck hard for long periods. Left unchecked, excessive EGTs can reduce engine efficiency and potentially damage components like the turbocharger, pistons, valves, and exhaust manifold.

The good news is that there are several proven ways to lower EGTs on a 6.7 Cummins while improving reliability and performance at the same time.

In this guide, we’ll break down what causes high EGTs, what temperature range is considered safe, and the best upgrades and driving habits to keep your Cummins running cooler.

What Are EGTs?

EGT stands for Exhaust Gas Temperature. It measures how hot the exhaust gases are as they leave the engine. On diesel trucks like the 6.7 Cummins, EGTs are especially important because diesel engines generate substantial heat under load.

An EGT gauge typically measures temperatures in the exhaust manifold before the turbocharger, which provides the most accurate reading for engine safety.

Why High EGTs Matter

Excessively high EGTs can lead to:

• Turbocharger damage
• Cracked exhaust manifolds
• Melted pistons
• Reduced fuel economy
• Premature engine wear
• Head gasket issues

If you regularly tow, haul, or run aggressive tuning, monitoring EGTs should be a priority.

What Is a Safe EGT for a 6.7 Cummins?

Most diesel enthusiasts consider these temperature ranges safe for a 6.7 Cummins:

Brief spikes are usually acceptable, but sustained temperatures above 1,350–1,400°F should be avoided whenever possible.

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Common Causes of High EGTs on a 6.7 Cummins

Before you can lower EGTs, it helps to understand what’s causing them.

Heavy Towing

Pulling large trailers or climbing steep grades places significant demand on the engine. More fuel and boost equal more heat.

Aggressive Tuning

Performance tuners that add excessive fuel without proper airflow can dramatically increase EGTs.

Restricted Airflow

Dirty air filters, restrictive intake systems, or clogged intercoolers reduce airflow and increase combustion temperatures.

Turbocharger Limitations

A stock turbo can struggle to efficiently move enough air at higher horsepower levels, causing heat buildup.

Exhaust Restrictions

The factory emissions system and restrictive exhaust components can trap heat in the engine.

Best Ways to Lower EGTs on a 6.7 Cummins

1. Upgrade the Intake System

One of the simplest ways to reduce EGTs is by improving airflow into the engine.

A high-flow cold air intake helps your Cummins breathe easier by delivering cooler, denser air. More oxygen improves combustion efficiency and reduces excess heat.

Benefits include:

• Lower EGTs under load
• Improved throttle response
• Better turbo efficiency
• Increased airflow

For towing applications, even a small drop in EGTs can make a noticeable difference during long climbs.

2. Install a High-Flow Exhaust System

The factory exhaust system on many diesel trucks is restrictive, especially on emissions-equipped models.

A larger diameter aftermarket exhaust helps reduce backpressure and allows heat to escape more efficiently.

Popular options include:

• 4-inch exhaust systems
• 5-inch turbo-back exhausts
• High-flow mufflers

Reducing exhaust restriction often results in:

• Lower EGTs
• Faster turbo spool
• Improved fuel economy
• Better overall engine efficiency

3. Upgrade the Intercooler

The intercooler cools compressed air coming from the turbocharger before it enters the engine.

Hot intake air leads to higher combustion temperatures and increased EGTs.

A larger aftermarket intercooler can:

• Lower intake air temperatures
• Improve towing performance
• Reduce heat soak
• Stabilize EGTs during long pulls

This upgrade is especially useful for tuned or heavily worked trucks.

4. Use Proper Tuning

Not all tuning is created equal.

Some aggressive tunes dump excessive fuel into the engine without supplying enough airflow, which creates unnecessary heat.

A quality custom tune designed for towing or daily driving can significantly reduce EGTs while still improving performance.

Look for tuning that focuses on:

• Balanced air/fuel ratios
• Efficient turbo management
• Safe timing adjustments
• Towing-specific calibrations

Good tuning can often lower EGTs more effectively than bolt-on parts alone.

5. Upgrade the Turbocharger

If your truck is making higher horsepower or towing heavy regularly, the stock turbo may become inefficient.

A larger or more efficient turbocharger moves more air at lower temperatures, helping control EGTs under heavy load. Our 2007.5-2018 6.7 Cummins TNT HE300VG 63mm turbo or 2019-2024 6.7 Cummins TNT HE300VG 63mm turbo are great options.

Turbo upgrades can provide:

• Cooler exhaust temperatures
• Increased airflow
• Better towing performance
• Improved reliability at higher power levels

However, turbo sizing matters. Going too large can hurt drivability and spool time.

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6. Monitor EGTs with a Pyrometer

You can’t manage what you can’t monitor.

Installing a pyrometer gauge gives you real-time EGT readings so you know when temperatures are climbing too high.

This is one of the most valuable upgrades for anyone who:

• Tows regularly
• Runs aftermarket tuning
• Uses larger tires
• Frequently drives in mountainous terrain

Monitoring EGTs allows you to adjust driving habits before temperatures become dangerous.

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7. Adjust Your Driving Habits

Sometimes lowering EGTs comes down to driving smarter.

Downshift Earlier

Letting the engine lug in a high gear increases load and heat. Downshifting keeps RPMs in a more efficient range.

Reduce Throttle Input

Full throttle for extended periods creates excessive heat. Slightly easing off can lower EGTs quickly.

Maintain Highway Speeds

Pushing heavy loads at high speeds dramatically increases exhaust temperatures.

Avoid Excessive Idling After Hard Pulls

Allow the turbo to cool properly before shutting the truck off after towing or spirited driving.

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8. Keep Up with Maintenance

Poor maintenance can contribute to elevated EGTs.

Be sure to regularly inspect:

• Air filters
• Fuel filters
• Boost leaks
• Intercooler boots
• Turbocharger condition
• Exhaust leaks

Even small airflow or fueling issues can cause unnecessary heat buildup.

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Do Emissions Systems Affect EGTs?

Yes. The factory emissions system on the 6.7 Cummins can contribute to higher EGTs.

Components like the:

• EGR system
• DPF (Diesel Particulate Filter)
• SCR system

can increase exhaust restriction and heat during regeneration cycles.

Many owners notice lower EGTs after upgrading certain components for off-road or competition applications where legally permitted. Always follow local emissions regulations and laws in your area.

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Best Combination for Lower EGTs

For most 6.7 Cummins owners, the ideal setup includes:

• High-flow intake
• Free-flowing exhaust
• Quality towing tune
• Upgraded intercooler
• EGT monitoring gauge

This combination improves airflow, reduces restriction, and helps keep temperatures under control without sacrificing drivability.

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Final Thoughts

Managing EGTs on a 6.7 Cummins is critical for both performance and long-term reliability. Whether you tow heavy every weekend or simply want to protect your investment, lowering exhaust gas temperatures helps your truck run more efficiently and safely.

The best approach is usually a combination of airflow upgrades, proper tuning, and smart driving habits. By addressing the root causes of high EGTs, you can improve towing confidence, reduce engine stress, and get more life out of your Cummins.

For high-quality diesel performance parts and upgrades for your Cummins build, visit Black Sheep Industries

What causes high EGTs on a 6.7 Cummins?

High EGTs are commonly caused by heavy towing loads, excessive fueling, restricted airflow, poor tuning, clogged exhaust components, or an undersized turbocharger.

What is considered high EGT on a 6.7 Cummins?

Sustained EGTs above approximately 1,250°F under load are generally considered high for long-term towing and heavy-duty use.

Can upgrading the turbo lower EGTs?

Yes. A more efficient turbocharger can improve airflow and reduce exhaust backpressure, which often helps lower EGTs under towing and acceleration.

Does tuning affect EGTs?

Absolutely. Poor or overly aggressive tuning can dramatically increase EGTs. Proper tuning matched to the turbo and fueling setup is critical for controlling heat.

Will a better intercooler reduce EGTs?

An upgraded intercooler can help reduce intake air temperatures and improve combustion efficiency, which may contribute to lower EGTs.

Why are EGTs important on a diesel truck?

Excessive EGTs can damage pistons, valves, turbochargers, and exhaust components over time. Monitoring EGTs is especially important for towing and tuned diesel trucks.

Can clogged emissions systems increase EGTs?

Yes. Restrictions in the DPF or other emissions components can increase exhaust backpressure and contribute to elevated exhaust temperatures.

Is a VGT turbo good for controlling EGTs?

Yes. Variable geometry turbos are often effective at maintaining responsive airflow and improving towing efficiency, helping manage EGTs during heavy loads.

Related 6.7 Cummins Turbo Articles

• HE300VG vs Fixed Geometry Turbo for 6.7 Cummins
• Best Turbo Upgrades for Towing With a 6.7 Cummins

Many diesel owners choose a 6.7 Cummins VGT turbo upgrade to maintain factory-style drivability while supporting additional power and lower exhaust temperatures. For 2019–2024 applications, the 63mm TNT HE300VG turbo  is designed to deliver strong towing performance without sacrificing spool response.

Common Upgrades to Help Lower EGTs on a 6.7 Cummins

Upgrade	Primary Benefit	Impact on EGTs
Upgraded HE300VG Turbo	Improved Airflow	Helps Lower EGTs Under Load
Custom Diesel Tuning	Optimized Fuel Delivery	Can Significantly Reduce Heat
High-Flow Intake System	Reduced Air Restriction	Moderate Improvement
Upgraded Intercooler	Lower Intake Temperatures	Helps Improve Efficiency
Free-Flowing Exhaust	Reduced Backpressure	Can Improve Exhaust Flow
Proper Towing Tune	Controlled Fueling	Major EGT Reduction Potential
Regular Maintenance	Improved Engine Efficiency	Helps Prevent Excessive Heat