We researched and compared the top turbos for the 12V Cummins engine, analyzing manufacturer specs, industry standards, and aggregated owner feedback. Our evaluation focuses on real-world performance, durability, and value to help you choose the right upgrade for your truck. Whether you’re towing, daily driving, or chasing high horsepower, this guide breaks down the best options.
| Photo | Product | Score | Buy |
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BorgWarner S300 SX-E 63/68 Best Overall 63mm inducer / 68mm exducer, T4 divided housing, 360-degree thrust bearing |
9.2 | 🛒 Check Price |
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Holset HE351VE Best VGT Option Variable geometry turbo, 60mm compressor, electronic actuator, T3 flange |
8.7 | 🛒 Check Price |
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Garrett GT3788R High Horsepower Pick 88mm compressor, 78mm turbine, T4 divided housing, ball bearing center section |
8.4 | 🛒 Check Price |
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Precision Turbo 6266 Gen 2 Great Value 66mm compressor, 62mm turbine, T4 divided housing, journal bearing |
8.1 | 🛒 Check Price |
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HTT Super B Special 62/65/14 Best for Towing 62mm inducer, 65mm exducer, 14cm turbine housing, T4 flange |
8.0 | 🛒 Check Price |
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Fleece Cheetah 62/68/14 Upgraded OEM Replacement 62mm inducer, 68mm exducer, 14cm housing, T3 flange, journal bearing |
7.8 | 🛒 Check Price |
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Bullseye Power S364.5 SX-E Budget High Flow 64.5mm compressor, 74mm turbine, T4 divided housing, journal bearing |
7.3 | 🛒 Check Price |
1. BorgWarner S300 SX-E 63/68: Best Overall
The BorgWarner S300 SX-E 63/68 is widely regarded as the sweet spot for 12V Cummins owners seeking a reliable power increase. In our research, owner feedback consistently praises its quick spool and strong mid-range pull, making it ideal for daily driving and towing. The billet compressor wheel and heavy-duty thrust bearing deliver durability that matches the engine’s reputation. However, we noted some users report the need for upgraded injectors or a tuner to fully utilize the turbo’s capacity.
This turbo is not the best choice for those chasing extreme horsepower beyond 700 hp or for budget builds. If you plan to run high boost levels continuously, a larger S400 series may be more appropriate. For most enthusiasts, the S300 SX-E 63/68 offers the best all-around performance without excessive lag.
- Proven S300 frame with billet compressor wheel for excellent flow and quick spool.
- Durable 360-degree thrust bearing and high-temp alloy turbine for long life.
- Supports up to 650 hp with stock injection; great for daily driving and moderate towing.
Pros: Excellent balance of quick spool and top-end power.; Robust construction; reliable for street and mild race use.
Cons: May require upgraded fuel system to reach full potential.
2. Holset HE351VE: Best VGT Option
The Holset HE351VE is a popular swap for 12V Cummins owners who want variable geometry benefits. Based on owner feedback, this turbo provides near-instant spool and smooth boost delivery, making it excellent for towing and stop-and-go driving. We compared its specs against the BorgWarner S300 and found the HE351VE offers superior low-end response but falls short on top-end flow for high-horsepower builds. The integrated electronic actuator requires a controller or custom tuning, which adds complexity.
We caution that the actuator and vanes can carbon up over time, leading to sticking issues. This turbo is best for those who prioritize low-end torque and are comfortable with aftermarket electronics. Skip it if you want a simple, mechanical turbo or plan to exceed 500 hp.
- Variable geometry vanes for precise boost control and quick spool from idle.
- Factory-equipped on later Cummins; proven reliability with proper maintenance.
- Great for towing and daily driving with improved fuel economy under light load.
Pros: Excellent low-end response; minimal lag.; Can improve fuel economy when driven conservatively.
Cons: Electronic actuator can be problematic; requires control system (e.g., standalone controller).
3. Garrett GT3788R: High Horsepower Pick
The Garrett GT3788R is a high-flow ball bearing turbo designed for serious power. In our evaluation of spec sheets and owner reports, this turbo delivers impressive top-end flow and can support over 700 hp when paired with upgraded fuel systems and head studs. The ball bearing cartridge helps it spool faster than comparable journal bearing turbos, but it still exhibits noticeable lag on a stock 12V. Many owners note that it shines on the drag strip or in competition but can be frustrating in traffic.
We recommend this turbo only for enthusiasts building a high-horsepower street or race truck. If you need a responsive daily driver or tow vehicle, the lag may be unacceptable. Also, the price is significantly higher than journal bearing alternatives, so value-conscious buyers should look elsewhere.
- Ball bearing center section for faster spool and reduced friction.
- Large 88mm compressor wheel supports 700+ hp with proper supporting mods.
- Durable billet wheel and high-flow turbine housing for top-end power.
Pros: Capable of high horsepower (700+ hp) with good response for its size.; Ball bearing design improves transient response over journal bearing units.
Cons: Significant lag compared to smaller turbos; not ideal for daily driving.
4. Precision Turbo 6266 Gen 2: Great Value
The Precision Turbo 6266 Gen 2 is a popular entry-level upgrade for 12V Cummins owners on a budget. Based on owner feedback and spec comparisons, this turbo delivers solid mid-range power and can support up to 600-650 hp with proper tuning. The journal bearing design is cost-effective but may require more frequent oil change intervals to maintain longevity. We found that many users appreciate the balance of performance and price, though some report that the turbo can be laggy below 2000 RPM.
This turbo is a good choice if you’re building a street-driven truck with occasional towing or racing. However, if you demand the quickest spool possible or plan to run high boost for extended periods, consider a ball bearing upgrade. Also, the 6266 may not be ideal for those aiming for 700+ hp without a larger unit.
- Proven 66mm compressor wheel for strong mid-range and top-end power.
- Journal bearing design offers a budget-friendly option without sacrificing reliability.
- Supports up to 650 hp; good for street and mild strip use.
Pros: Affordable price point for the performance level.; Good spool characteristics for a turbo of this size.
Cons: Journal bearing may not last as long as ball bearing under extreme use.
5. HTT Super B Special 62/65/14: Best for Towing
The HTT Super B Special is a towing-oriented turbo that prioritizes low-end torque over peak horsepower. In our research, owner feedback from heavy-towing applications highlights its ability to build boost quickly and maintain EGTs. The 14cm turbine housing helps spool, but it also restricts top-end flow, making this turbo unsuitable for high-horsepower builds. We compared it to the BorgWarner S300 and found the HTT offers better low-end response but significantly less top-end power.
This turbo is perfect for those who primarily tow heavy trailers and want a reliable, responsive setup. Skip it if you plan to race or want a turbo that can support over 450 hp. Also, the journal bearing may not hold up as well under sustained high boost, so keep boost levels moderate.
- Designed for quick spool and strong low-end torque, ideal for towing.
- Durable journal bearing with heavy-duty thrust washer for longevity.
- Direct bolt-on for stock exhaust manifold; minimal modifications needed.
Pros: Excellent low-end response; pulls strong from 1800 RPM.; Easy installation; fits stock location without major changes.
Cons: Limited top-end power; runs out of steam above 2500 RPM.
6. Fleece Cheetah 62/68/14: Upgraded OEM Replacement
The Fleece Cheetah 62/68/14 is designed as an upgraded replacement for the factory HX35 turbo on 12V Cummins. In our evaluation, it offers a minor increase in flow and durability over stock, making it a good choice for truck owners who need a new turbo and want a little extra performance. Owner feedback indicates it spools similarly to stock and can handle mild tuning, but it is not intended for high power levels. Some users reported that the boost pressure can spike if the wastegate is not adjusted properly.
This turbo is best for those restoring a stock truck or doing a budget rebuild. If you want significant power gains or plan to run higher boost, look at the BorgWarner or Holset options. The Cheetah is limited to around 400 hp, and pushing it further risks overspeeding the compressor.
- Direct replacement for stock HX35; bolts on without modifications.
- Slightly larger compressor wheel than stock for moderate power gains.
- Good for mild upgrades (up to 400 hp) with stock injection.
Pros: Simple bolt-on; no need for new manifolds or downpipes.; Affordable way to replace a worn stock turbo with some extra flow.
Cons: Modest power gains; not for those seeking big horsepower.
7. Bullseye Power S364.5 SX-E: Budget High Flow
The Bullseye Power S364.5 SX-E is a budget-oriented turbo that offers impressive flow for its price point. In our research, owner feedback is mixed: many report good power gains and decent spool for a 64.5mm turbo, but a significant number mention oil leakage from the center section, often traced to inadequate drain line setup or quality control. We compared its specs to the BorgWarner S300 and found the Bullseye flows similarly but with less consistent build quality. The journal bearing is adequate for street use but may not hold up under continuous high boost.
We recommend this turbo for experienced builders who can address potential oiling issues and are looking for maximum flow per dollar. Skip it if you want a hassle-free install or plan to rely on the turbo for daily driving without tinkering. For most, the extra cost of a BorgWarner or Garrett is worth the reliability.
- Large compressor wheel for high flow at a lower price than competitors.
- Journal bearing design keeps cost down but may sacrifice longevity.
- Can support up to 600 hp with proper fueling and tuning.
Pros: High flow capacity for the price.; Good for street/strip builds on a tight budget.
Cons: Notorious for oil leak issues if not installed with proper drain line.
Frequently Asked Questions
What size turbo is best for a stock 12V Cummins?
For a stock 12V Cummins with no internal upgrades, a turbo in the 62-66mm compressor range is ideal. The BorgWarner S300 SX-E 63/68 or Holset HE351VE provide good power gains without overworking the stock fuel system. Larger turbos may cause excessive lag and require supporting mods.
Do I need to upgrade my fuel system when installing a bigger turbo?
Yes, for turbos capable of over 500 hp, upgraded injectors and a fuel pump are recommended to prevent leaning out. Even with a moderate turbo like the S300, a tuner and lift pump help optimize performance and EGTs. Always monitor exhaust gas temperatures.
What is the difference between journal bearing and ball bearing turbos?
Ball bearing turbos have lower friction, spool faster, and are more durable under high RPM, but cost more. Journal bearing turbos are cheaper and more tolerant of oil contamination, but have more lag and may wear faster under extreme use. For daily driving, journal bearings are fine; for racing, ball bearings offer an edge.
Will a variable geometry turbo (VGT) work on my 12V Cummins?
Yes, but it requires a standalone controller or custom tuning to operate the actuator. The Holset HE351VE is a common VGT swap. VGTs provide excellent low-end response and can improve fuel economy, but add complexity and potential reliability concerns with the vanes.
How much horsepower can a 12V Cummins handle with a turbo upgrade?
With a quality turbo and supporting mods (head studs, upgraded injectors, and fuel system), a 12V can handle 500-700 hp reliably. The BorgWarner S300 is good for 600 hp, while the Garrett GT3788R can push 700+. Beyond that, internal upgrades like pistons and rods are necessary.
Our Verdict
After researching specs and owner feedback, our top pick is the BorgWarner S300 SX-E 63/68 for its excellent all-around performance, durability, and value. It suits most 12V Cummins owners from daily driving to towing and mild racing. The runner-up is the Holset HE351VE for those who want variable geometry benefits and are willing to manage the extra complexity. Choose based on your power goals and tolerance for installation effort.
Last reviewed and spec-checked: June 15, 2026. We re-check our picks and listings periodically.
