Holset – a turbocharger manufacturer of British origin, best known for robust and reliable solutions for heavy-duty transport and industrial engines. The company was founded in 1952, combining the surnames of two engineers – Brian Holmes and Paul Croset – which gave rise to the name "Holset." In its early years, the company specialized in developing turbos for massive diesel units, where durability and resistance to high thermal loads were crucial. In this field, Holset quickly made a name for itself by offering high-quality and efficient systems for specific needs such as truck, bus, and construction equipment engines.
In 1973, Holset became part of the Cummins corporation and officially began operating as Cummins Turbo Technologies. Cummins is one of the largest diesel engine manufacturers in the world, and this partnership allowed Holset to further expand its technological capabilities and reach a broader market. Today, the Holset brand is still maintained under the Cummins Turbo Technologies division, emphasizing its unique historical value and extensive experience in turbo manufacturing.
Holset stands out for its focus on large-volume, mostly diesel, engines. For example, the popular HX series turbos (e.g., HX35, HX40, HX50) are widely used in trucks, tractors, marine engines, and other heavy-duty vehicles. The HX35 is often found in lighter trucks and commercial vans, while larger models like the HX50 are adapted for higher-power diesel engines that operate continuously and endure massive thermal and mechanical loads.
Cummins' integrated strategy means that many Holset products are specifically designed to leverage Cummins engine architecture: from air delivery systems to exhaust gas flow management. This close collaboration allows for optimization of the entire engine and turbocharger chain, ensuring lower emissions, better fuel efficiency, and greater reliability. This synergy is also evident among other heavy-duty engine manufacturers, for whom Holset products are a suitable alternative due to their stable, long-term performance.
Holset (Cummins Turbo Technologies) continuously seeks ways to improve turbocharger efficiency in diesel engines. One of the most significant advancements is the Variable Geometry Turbocharger (VGT), which allows for adjusting the impeller vanes to suit different engine RPM ranges. This method reduces so-called turbo lag and helps maintain consistent power across a wider RPM range. As a result, long-haul trucks or vehicles carrying heavy loads benefit from even power distribution, fewer "dead zones," and better fuel economy.
On the other hand, Holset invests heavily in materials engineering, particularly in the development of durable alloys capable of withstanding extreme heat and pressure. Since diesel engines operate at higher temperatures, it is crucial that the turbo housing and rotor maintain stability. The top product lines feature precision bearing solutions that reduce friction and allow for higher boost pressure earlier, while also extending the unit's lifespan.
The Holset name is primarily associated with durability, longevity, and the ability to perform under extreme conditions. These turbos are built to withstand heavy loads, often operating in conditions ranging from high RPMs to long, uninterrupted work periods, which is why Holset products are highly valued in the trucking, agricultural, and other commercial vehicle segments. Quality and reliability are the core traits that allow the manufacturer to maintain a solid niche in the global market.
However, when it comes to the passenger car market or tuning projects, Holset turbos are less common. Due to the relatively large mass of the rotor and impeller, they can cause significant turbo lag in smaller engines. Additionally, the initial design of these units is more focused on maintaining high torque during continuous operation rather than quick throttle response, which is often desired by motorsport enthusiasts. Thus, Holset solutions are more commonly seen in specialized diesel performance modifications, where diesel power is pushed to extremely high limits.
Despite being most closely associated with diesel engines, Holset, as part of Cummins, is actively monitoring the growing trends in electrified transport. In the future, some engines may be replaced by hybrid or fully electric powertrains, but Holset remains important in developing alternative fuel technologies such as compressed natural gas (CNG), hydrogen, or even biofuels. The company's engineers aim to leverage their accumulated experience to create technologies that could transform the heavy-duty transport sector into a less polluting and more efficient industry, adapting to new market directions.
Holset (Cummins Turbo Technologies) will continue to be a strong name among commercial transport operators and engineering specialists who value not only power but also durability metrics. The close relationship with Cummins, one of the most renowned diesel engine manufacturers, ensures that Holset will also gain new opportunities in exploring electrified turbochargers or smart exhaust gas management systems that reduce emissions and improve engine efficiency. Thus, while Holset may not be as common a brand in the passenger car world as Garrett or BorgWarner, in the heavy-duty segment, this manufacturer remains one of the leaders shaping industry standards.