Turbochargers Holset

Updated May 12, 2026

For the canonical Holset brand-tier coverage including the full Cummins Turbo Technologies (CTT) corporate context, see the Read the Holset brand-tier guide — this page focuses on the aftermarket-replacement cross-shop and frame-size upgrade-path coverage.

The HX-Series Frame-Size Naming Convention

Holset names fixed-geometry turbocharger frames with the HX prefix followed by a 2-digit size code. Higher numbers indicate larger frames: HX30 (smallest, 20-30mm inducer compressor wheel) through HX55 (largest industrial, 90+mm inducer). The HX naming convention dates to the original Holset Engineering Co. catalog before the 1973 Cummins acquisition and continues across the current Cummins Turbo Technologies product line.

Frame-size mapping to power band. HX30 covers 50-150 hp applications. HX35 covers 230-400 hp (Cummins 5.9L 12-valve and 24-valve pickup). HX40 covers 400-650 hp (Cummins ISL medium-duty, selected ISC heavy-truck). HX50 covers 500-800 hp (Cummins ISM heavy-truck). HX52 covers 600-1,000 hp (Cummins ISX heavy-truck variants). HX55 covers 800-1,200 hp (largest Cummins ISX industrial applications). Each frame ships with multiple A/R ratio options on the turbine housing for application-specific fitment.

"Cummins 5.9L 12-valve owners chasing 500-600 hp at the wheels routinely run the HX35 → HX40 upgrade. Same exhaust manifold flange fits both frames on most chassis; the larger HX40 inducer adds 60-80 lb/min mass airflow capacity that the HX35 cannot reach. Spool is 600-800 RPM slower with the HX40, but the peak power gain on the same fuel system justifies the spool tradeoff." — r/Cummins / r/cumminsforum synthesis on the Holset HX35 → HX40 upgrade path across the 5.9L community.

HE-Series Variable-Geometry Frames

Holset names variable-geometry turbocharger frames with the HE prefix. HE-series uses moveable vanes inside the turbine housing to change effective cross-section on demand, eliminating the spool-vs-peak compromise that HX-series fixed-geometry forces on the designer.

HE-series frame mapping. HE351CW (fixed-geometry despite the HE prefix; covers 2003-2007 Cummins 5.9L 24-valve common-rail). HE351VE (variable-geometry; 2007.5-2012 Cummins 6.7L Ram 2500/3500/4500/5500). HE300VG (variable-geometry; 2013-2025 Cummins 6.7L). HE400VG and HE451VE (variable-geometry; Cummins ISX heavy-truck variants). The HE-series VGT mechanism uses an electronic actuator to drive a unison ring that rotates moveable vanes through a 60-90 degree angular range. Actuator failure at 100,000-180,000 miles is the dominant aftermarket failure mode on the Cummins 6.7L install base; the Stage 2 actuator-only repair path at $200-$700 versus complete-turbo replacement at $1,500-$2,500 saves $1,000-$1,800 per failure event.

The HE351VE above defines the 2007.5-2012 first-generation Cummins 6.7L install base. Mid-2013 Cummins released the HE300VG as the second-generation VGT replacement: smaller compressor wheel for faster low-RPM spool, revised electronic actuator with an improved 200,000-mile fatigue rating, and an installed-cost reduction at the OE level. The HE300VG covers 2013-2025 Ram 2500/3500/4500/5500 production and is the dominant actuator-failure replacement target on every aftermarket cross-reference page below.

Aftermarket Holset Cross-Shop in Detail

The Holset aftermarket cross-shop runs across three tiers with documented pricing and warranty characteristics. OEM Holset rebuilt direct through Cummins service network ($1,200-$2,500 depending on frame, 12-24 month factory warranty terms). Specialty-tier rebuilt Holset through Fleece Performance, BD Diesel, Industrial Injection, HPT, Bullseye Power, KC Turbos distributors ($1,500-$3,500 with documented Stage upgrade options). Budget aftermarket Chinese cross-references through BuyAutoParts, ASDPI, Dofoch, generic Amazon and eBay sources ($700-$1,500 with shorter service life).

The cross-shop math on a Cummins 5.9L 12-valve HX35 example. OEM Holset rebuilt direct: $1,200-$1,800 with documented factory warranty terms. Fleece Cheetah HX35 specialty rebuild: $2,500-$3,500 with documented dyno-proven Stage 2 upgrade. BuyAutoParts 40-30796AN budget cross-reference: $800-$1,300 with 1-year limited warranty. For most daily-driver 12-valve owners with a failed OEM unit, the BuyAutoParts cross-reference makes the most structural sense on depreciation-adjusted spend. For builds chasing documented Stage 2 dyno-proven power gains, Fleece Cheetah is the documented community pick. For fleet commercial applications wanting documented warranty terms across a fleet, OEM Holset rebuilt direct is the right tier.

Holset in the Broader OEM-Supplier Cross-Shop

Holset competes against Garrett and BorgWarner on heavy-duty diesel OEM applications. The decision pattern flips by OEM platform rather than head-to-head brand comparison. Cummins applications run Holset; Ford 6.7L Power Stroke runs Garrett; GM Duramax runs BorgWarner / Garrett split depending on generation. The OEM cross-shop is therefore application-specific.

For Cummins-platform owners specifically, the relevant brand-tier cross-shop runs within the Holset family (OEM-rebuilt vs specialty-tier rebuilt vs budget Chinese) rather than across brands. Buyers don\'t pick between Holset and Garrett on a Cummins 6.7L Ram pickup — they pick between OEM Cummins service Holset, Fleece Performance Holset rebuild, BD Diesel Holset rebuild, Industrial Injection Holset rebuild, or budget ASDPI / Dofoch Holset cross-reference. The brand is determined by the chassis; the tier is determined by the buyer\'s budget and Stage target.

The Cummins community pattern that emerges from this market structure: most aftermarket replacement work concentrates around the highest-volume passenger-pickup frames (HX35 on 12-valve / 24-valve 5.9L, HE351VE on 6.7L 2007.5-2012, HE300VG on 6.7L 2013-current). The heavy-truck industrial frames (HX52, HX55, HE400VG) see less aftermarket cross-reference availability because fleet operators typically run OEM-rebuilt direct with documented warranty contracts rather than budget aftermarket replacement. The chassis-specific market split is structural — passenger pickup buyers run on per-unit replacement economics, while fleet operators run on uptime-guarantee economics that favor OEM warranty depth regardless of price gap between OEM-rebuilt and budget Chinese cross-reference.

For the canonical Holset brand-tier coverage, the Read the Holset brand-tier guide covers the full Cummins Turbo Technologies corporate context plus the broader catalog. For the VGT architecture that Holset HE-series uses, the Read the VGT architecture explainer covers the vane mechanism. For compound twin-turbo applications pairing Holset HX35 primaries with BorgWarner S400 secondaries, the Read the compound turbocharger guide covers the architecture. For the broader cross-engine roundup, the Read the cross-engine roundup covers documented picks. For the budget-tier Holset HX35 aftermarket cross-reference review on the Cummins 6BT 5.9L install base, the Read the BuyAutoParts 40-30796AN review covers the documented entry-tier replacement experience.

For deeper engineering background, the Turbocharger reference covers compressor-and-turbine fundamentals. The Cummins Turbo Technologies technical library publishes Holset OE specifications and compressor maps. The Turbo University reference publishes industrial-tier balance-and-test discipline applicable to Holset rebuilds. The Turbocharger Rebuilding Distribution catalog publishes OE manifest cross-references for the Cummins / Holset install base.

Holset Cross-Shop Decision Questions

What is the difference between HX35 and HX40 Holset turbos?

HX35 covers 1994-2002 Cummins 5.9L 12-valve and 24-valve applications with factory power ratings 230-400 hp. HX40 is the next-frame-size-up Holset covering Cummins ISL medium-duty and selected ISC heavy-truck applications with factory power ratings 400-650 hp. The HX35 → HX40 upgrade is the most common Holset frame-size-up path in the Cummins community, fitting the same exhaust manifold flange on most 5.9L applications and delivering documented 50-200 hp gains at the cost of slightly slower spool.

Can you upgrade from HX35 to HX52?

HX52 is the larger industrial-tier Holset frame covering Cummins ISL / ISM / ISX heavy-truck applications. Upgrading from HX35 to HX52 on a Cummins 5.9L 12-valve pickup is possible but requires custom exhaust manifold, larger intercooler plumbing, and substantial fueling upgrades. Documented HX35-to-HX52 builds reach 600-800 horsepower at the rear wheel. The HX52 is structurally over-spec for 5.9L pickup applications under 600 hp; the HX40 covers the same power band with cleaner spool.

How long does a Holset HX35 last?

OEM Holset HX35 on stock 1994-2002 Cummins 5.9L applications routinely reaches 300,000-400,000 miles with proper oil-change discipline (every 5,000-7,500 miles, synthetic oil). The HX35 is the documented reliability benchmark in the heavy-duty diesel community. Specialty-tier rebuilds (Fleece Cheetah HX35, BD Diesel Killer B HX35, Industrial Injection PhatShaft HX35) match OEM service life with slightly higher peak performance. Aggressive Stage 2-3 upgrades see shorter service life proportional to peak boost above OEM.

Where can you buy a Holset turbo?

OEM Holset rebuilt direct through Cummins service network (highest price, factory warranty terms). Specialty-tier rebuilt Holset through Fleece Performance, BD Diesel, Industrial Injection, HPT, Bullseye Power distributors. Budget aftermarket cross-references via Amazon, eBay, and rockauto.com (BuyAutoParts 40-30796AN, ASDPI, Dofoch). The right channel depends on Stage target and warranty depth preference; OEM warranty matters for fleet commercial; budget tier wins for daily-driver depreciation-adjusted spend.

What does HX mean in Holset turbo names?

HX is the Holset naming convention for fixed-geometry (wastegated or non-wastegated) turbocharger frames sized by inducer diameter and exhaust housing A/R ratio. Higher numbers indicate larger frames: HX30 (smallest), HX35, HX40, HX50, HX52, HX55 (largest industrial). HE-series prefix indicates variable-geometry frames (HE351VE, HE300VG, HE400VG, HE451VE). The naming convention dates to the original Holset Engineering Co. catalog before the 1973 Cummins acquisition and continues across the current Cummins Turbo Technologies (CTT) product line.

Are Holset turbos better than Garrett?

For Cummins diesel applications, Holset is the OEM supplier and wins by being the factory choice. For Ford 6.7L Power Stroke and selected GM Duramax applications, Garrett is the OEM supplier and wins by the same logic. Cross-brand comparison on engineering criteria: Holset and Garrett carry comparable balance discipline, compressor map documentation, and bearing-design quality. The cross-shop is application-specific rather than head-to-head — buyers don't pick between Holset and Garrett, they pick between the OEM supplier for their chassis and the aftermarket cross-reference for that supplier.

Is the HX35 a variable-geometry turbo?

No — the Holset HX35 is a fixed-geometry turbocharger with a wastegate (some HX35 variants) or no wastegate (HX35 non-wastegated variants on selected Cummins applications). Variable-geometry came to the Cummins pickup line in 2007.5 with the HE351VE on the 6.7L 2007.5-2012 generation. Pre-2007 Cummins 5.9L pickup applications all used fixed-geometry HX35 or HE351CW. The HX-series naming convention indicates fixed-geometry; the HE-series naming indicates variable-geometry.