We researched and compared the top aftermarket turbos for the 6.5L GM diesel engine. Our evaluation is based on manufacturer specifications, published industry standards, and aggregated owner feedback. Whether you need a daily driver upgrade or a high-performance build, this guide will help you choose the right turbo for your needs.
| Photo | Product | Score | Buy |
|---|---|---|---|
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ATS Aurora 3000 Top Pick Single ball bearing, 360-degree thrust bearing, 0.80 A/R turbine housing |
9.2 | 🛒 Check Price |
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HE351VE Variable Geometry Turbo Best Variable Geometry Variable geometry, electronic actuator, 60mm compressor wheel |
8.9 | 🛒 Check Price |
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Holset HX35W Best Value Journal bearing, 56mm inducer, 9cm2 turbine housing |
8.6 | 🛒 Check Price |
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BD Diesel Super B Special Premium Build Billet compressor wheel, 360-degree thrust bearing, 0.80 A/R |
8.4 | 🛒 Check Price |
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GM-8 Replacement Turbo (OEM Style) Budget Pick Journal bearing, 51mm compressor, 0.80 A/R |
7.8 | 🛒 Check Price |
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Precision Turbo 5431 High Performance Journal bearing, 54mm inducer, 0.63 A/R turbine housing |
8.1 | 🛒 Check Price |
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Banks Power Sidewinder Turbo Efficient Towing Journal bearing, 58mm compressor, 0.80 A/R, wastegated |
8.3 | 🛒 Check Price |
1. ATS Aurora 3000: Top Pick
In our evaluation, the ATS Aurora 3000 stands out as the best overall turbo for the 6.5 diesel. Its ball bearing design provides quick spool and reduced lag, which owners frequently praise for improving daily drivability. The 0.80 A/R turbine housing is optimized for both towing and performance. Based on owner feedback, this turbo reliably supports up to 450 horsepower with supporting mods.
However, the Aurora 3000 is not the most budget-friendly option. If you are on a tight budget or only need a mild upgrade, you may find better value elsewhere. It is best suited for enthusiasts seeking serious performance gains without sacrificing reliability.
- Ball bearing center section reduces lag dramatically
- Direct bolt-on for 6.5L GM diesel, no modifications needed
- Supports up to 450 hp with proper fueling
Pros: Excellent spool time and low-end torque; High-quality materials and construction
Cons: Premium price point
2. HE351VE Variable Geometry Turbo: Best Variable Geometry
The HE351VE is a popular variable geometry turbo often swapped onto 6.5 diesels for its excellent response and efficiency. Based on owner feedback, it provides strong low-end torque and smooth power delivery. The electronic actuator allows fine-tuning of boost levels, which is ideal for those who want to dial in performance.
However, this turbo requires an adapter plate and custom tuning, making installation more involved. The variable geometry mechanism adds complexity and potential failure points. We recommend this for experienced DIYers who are comfortable with fabrication and tuning. If you prefer a simple bolt-on, consider a fixed geometry turbo instead.
- Variable geometry reduces lag and improves efficiency
- Electronic actuator allows precise boost control
- Common upgrade from Cummins swaps, requires adapter
Pros: Excellent throttle response across RPM range; Great for towing and heavy loads
Cons: More complex installation and tuning required; Actuator can fail if not properly maintained
3. Holset HX35W: Best Value
The Holset HX35W is a favorite among budget-conscious 6.5 diesel owners. We found that it offers a great balance of performance and durability for the price. Many owners report reliable service over tens of thousands of miles. The journal bearing design is simple and robust, and rebuild kits are widely available.
On the downside, the HX35W is not a direct bolt-on; it requires a custom mounting bracket and oil line modifications. Lag is more noticeable compared to ball bearing units. If you are looking for a no-hassle install, this may not be the best choice. But for those willing to do a little fabrication, it delivers excellent value.
- Proven reliability from Cummins applications
- Affordable price with good performance
- Easy to rebuild and find parts
Pros: Very cost-effective upgrade; Robust and durable construction
Cons: More lag than ball bearing turbos; Requires fabrication for mounting
4. BD Diesel Super B Special: Premium Build
The BD Diesel Super B Special is a direct bolt-on upgrade that uses a billet compressor wheel for increased airflow. In our research, it is praised for its build quality and reliability. It is a popular choice for those who want a straightforward upgrade without cutting or welding. The 360-degree thrust bearing adds durability under sustained load.
However, the Super B Special is priced at a premium, and its performance ceiling is lower than some larger turbos. If you are targeting over 400 hp, you might outgrow it quickly. It is best for daily drivers and mild performance builds that prioritize reliability and ease of installation.
- Billet wheel for improved airflow and strength
- Heavy-duty thrust bearing for longevity
- Direct replacement for stock GM-8 turbo
Pros: High-quality billet construction; Bolts on without modifications
Cons: Higher price than some competitors; Not ideal for extreme high-horsepower builds
5. GM-8 Replacement Turbo (OEM Style): Budget Pick
This OEM-style GM-8 replacement turbo is the most budget-friendly option for 6.5 diesel owners. It is designed to match factory specifications, making it a straightforward swap for a worn-out unit. Based on owner feedback, it restores stock performance reliably. It is ideal for those who just need to get their truck running again without spending much.
However, do not expect any power increase. The materials and bearings are not as robust as aftermarket upgrades. If you plan to tow heavy loads or want more power, you should look at an upgraded turbo. This is strictly for stock replacement on a budget.
- Exact OEM replacement, no modifications required
- Lowest cost option for stock performance
- Simple installation with standard tools
Pros: Very affordable; Easy bolt-on for stock replacement
Cons: No performance gain over factory; Less durable than aftermarket options
6. Precision Turbo 5431: High Performance
The Precision Turbo 5431 is a high-performance turbo aimed at racing and maximum power. Based on owner feedback, it delivers impressive top-end horsepower but at the expense of low-end torque. The 0.63 A/R housing helps spool quickly, but it can be prone to surge if the engine is lugged.
This turbo is not recommended for daily drivers or heavy towing. It requires careful tuning and may not be as durable under sustained loads. If you are building a competition truck or only care about drag racing, this could be a good fit. Otherwise, skip it.
- Designed for high-rpm power and racing
- Small turbine housing for quick spool
- Popular in competition diesel trucks
Pros: Strong mid-to-top end power; Fast spool with small housing
Cons: Not ideal for towing or daily driving; Can overboost if not tuned properly
7. Banks Power Sidewinder Turbo: Efficient Towing
The Banks Power Sidewinder turbo is engineered for towing and drivability. It features a wastegate to control boost and prevent overboosting, which is important for engine longevity. Based on owner feedback, it provides a noticeable improvement in low-end torque without sacrificing reliability. The kit includes everything needed for installation.
However, this turbo is not designed for maximum horsepower. If you are after high performance numbers, other options will outperform it. It is best for owners who tow regularly and want a reliable, easy-to-install upgrade that enhances everyday driving.
- Wastegated design for precise boost control
- Optimized for towing and low-end torque
- Includes all necessary mounting hardware
Pros: Great low-end torque for towing; Complete kit with instructions
Cons: Moderate price; Not the highest peak power
Frequently Asked Questions
What is the best turbo for a stock 6.5 diesel?
For a stock 6.5 diesel, we recommend the ATS Aurora 3000 or the BD Diesel Super B Special. Both are direct bolt-ons and provide a significant performance improvement without requiring engine modifications. The Aurora 3000 offers quicker spool, while the Super B Special is a bit more affordable.
Do I need to upgrade my fuel system when installing a bigger turbo?
Yes, if you install a turbo that significantly increases airflow, you will likely need to upgrade the fuel system to match. This includes injectors, injection pump, and possibly a lift pump. Failure to do so can result in lean conditions and engine damage. Always consult with a tuner for a balanced setup.
Can I install a turbo from a Cummins on my 6.5 diesel?
Yes, turbos like the Holset HX35W and HE351VE are commonly swapped onto 6.5 diesels. However, they require fabrication of mounting brackets, oil line modifications, and often an adapter plate. Tuning is also necessary to optimize performance. It is a popular mod for those with fabrication skills.
How do I know which turbo is compatible with my 6.5 diesel?
Check the turbo’s specifications against your engine’s year and configuration. Many aftermarket turbos are designed as direct replacements for the factory GM-8 turbo. If a turbo requires modifications, the manufacturer will typically list that. We always recommend verifying fitment with the seller or manufacturer before purchasing.
What maintenance is required for a turbocharger on a 6.5 diesel?
Regular oil changes with high-quality oil are crucial for turbo longevity. Let the engine idle for a minute before shutdown to allow the turbo to cool. Inspect the intake and oil lines for leaks periodically. Most journal bearing turbos can be rebuilt, while ball bearing units may need replacement if damaged.
Our Verdict
Our top pick is the ATS Aurora 3000 for its excellent performance, quick spool, and direct bolt-on fitment. For those on a budget, the Holset HX35W offers great value if you are willing to do some fabrication. The runner up is the BD Diesel Super B Special for those who want a premium, easy-to-install upgrade.
