IHI Turbochargers

Updated May 12, 2026

For direct cross-shop context against the broader OEM-supplier landscape, see the Read the Garrett brand-tier guide — IHI and Garrett split most modern factory turbo OEM business between them with BorgWarner and Mitsubishi as the other two major suppliers.

IHI Corporation — Brand Lineage and Market Position

IHI Corporation (formerly Ishikawajima-Harima Heavy Industries) is the Tokyo, Japan-based industrial conglomerate that owns its turbocharger business as part of a broader rotating-machinery and aerospace portfolio. The company traces its lineage to 1853 shipbuilding origins and entered turbocharger manufacturing in the 1960s. IHI now runs turbocharger manufacturing across Japan, Thailand, China, and Hungary, with R&D centers in Yokohama and Stuttgart.

The turbocharger business serves both OEM passenger-car applications and industrial diesel platforms. On the OEM passenger-car side, IHI is the documented factory supplier for Subaru WRX / STI VF-series across multiple generations, BMW B47 / B57 diesels, Mercedes-Benz OM651 diesel and AMG M177 V8 K07-class units, Mitsubishi Lancer Evolution selected generations, Nissan YD25DDTi diesel, and Hyundai/Kia 2.2 CRDi diesel. On the industrial side, IHI supplies heavy-truck diesel applications across the Japanese commercial vehicle market and stationary engine applications globally.

"Subaru WRX/STI owners running stock IHI VF-series turbos see service life into the 130,000-180,000 mile range when banjo-bolt oil supply maintenance is done at 80,000 miles. Skip that maintenance and the turbo dies at 100,000-130,000 miles. The IHI bearings are fine; the OEM oil supply line geometry is the limiting factor on Subaru applications." — r/WRX synthesis on the Subaru IHI VF-series maintenance pattern across the EJ257 install base.

The IHI Product Series Lineups

IHI catalogs turbochargers across multiple alphanumeric series tied to specific OEM applications: RHF for hi-flow small-displacement, RHB for compact applications, RHV for variable-geometry diesel, and VF as the Subaru-specific designation.

RHF (Roller-Bearing Hi-Flow) series covers small-displacement gasoline and diesel applications including Subaru EJ20 VF-series, Mitsubishi Evo RHF5 variants. RHB series covers compact applications including small-engine motorcycle turbos and OEM small-car installations. RHV series covers variable-geometry diesel applications. VF-series is the Subaru-specific designation cross-referenced under IHI naming conventions.

Subaru VF-series specific frames. VF22 / VF23 (early WRX / STI, 250-280 hp factory rating). VF34 / VF37 (USDM WRX, 230-265 hp factory). VF39 / VF43 (later USDM STI, 305 hp factory). VF44 / VF48 (current generation, 305-310 hp factory). The VF series uses single-scroll inlet configurations with cast aluminum compressor wheels on OEM-spec frames; aftermarket-Subaru VF builds (Stage 2 ports, larger turbines) push the OEM frames toward 350-400 hp targets on tuned applications.

OEM IHI Applications — Where Factory Installations Live

IHI is the factory turbocharger supplier across selected gasoline performance applications (Subaru WRX/STI, Mitsubishi Evo, Mercedes-AMG M177 V8) and diesel applications (BMW B47/B57, Mercedes OM651, Hyundai/Kia 2.2 CRDi, Nissan YD25DDTi).

The Subaru OEM relationship is the longest-running and highest-volume IHI passenger-car install base in the US market. Every WRX / STI from 2002 onward shipped with an IHI VF-series turbocharger at the factory; the relationship continued through the current 2024 STI Type RA generation. Mitsubishi Evo OEM relationship covers Evo VIII / IX (RHF5 variants); later generations switched suppliers. Nissan Skyline GT-R RB26DETT factory twin-turbo configurations used Garrett units for export markets and IHI units for some Japan-domestic variants.

Mercedes-AMG GT 63 / S 63 application is the largest single new IHI passenger-car factory installation of the 2020s — the M177 4.0L V8 ships with twin large IHI K07-class e-Turbo units feeding the cylinder banks. The application is one of the few production gasoline applications using e-Turbo integrated architecture (per the related electric-turbo coverage). The Mercedes / IHI relationship reflects IHI\'s historical strength in premium European OEM passenger-car turbocharger supply.

IHI Aftermarket Cross-Shop vs Garrett / Precision / BorgWarner

For aftermarket buyers chasing power above OEM spec, the IHI catalog is narrower than Garrett, Precision, or BorgWarner. The aftermarket IHI market concentrates around Subaru-tuner VF builds at $1,500-$3,500 for Stage 2-3 modifications.

IHI does not ship a broad performance-tuner catalog comparable to Garrett GTX / G-series or Precision PT-series. The catalog focuses on OEM supply rather than aftermarket performance variants.

For Subaru builds staying on the IHI family (OEM-tuner Stage 2 build), IHI aftermarket-Subaru builds remain the documented community default. For Subaru builds migrating to higher horsepower targets (400+ hp), the aftermarket community typically swaps to Garrett GTX2867R or Precision PT5862-class frames on a custom intake / exhaust manifold setup. The decision flips around the 350-400 hp target where the OEM IHI frame stops being efficient and the larger aftermarket frames start fitting cleanly.

For Mitsubishi Evo IX builds, the cross-shop pattern is similar — staying on the factory RHF5HB through Stage 2 modifications is the cost-effective path; migrating beyond 400 hp typically means a Garrett or Precision T3 frame swap. For Mercedes-AMG GT 63 and S 63 owners, no realistic aftermarket cross-shop exists; the IHI K07-class e-Turbo units are not replicable by third-party tuners, so OEM Mercedes parts are the only practical path.

For the broader OEM-supplier landscape, the Read the Garrett brand-tier guide covers Garrett OEM applications and aftermarket performance catalog. The Read the Borg Warner brand-tier guide covers BorgWarner OEM (Ford EcoBoost, VW Audi) and EFR aftermarket. For the small-engine application context where IHI RHB-class units dominate, the Read the small turbochargers guide covers the compact-frame category. For the broader cross-engine context, the Read the cross-engine roundup covers documented OE-replacement picks. For the small-engine cross-reference at the budget tier, the Read the Maxpeedingrods VZ21 RHB31 review covers the entry-tier alternative to OEM IHI on small-engine applications.

For deeper engineering background, the Turbocharger reference covers compressor-and-turbine fundamentals. The IHI Corporation technical library publishes the company\'s OEM and industrial product specifications. The Turbo University reference publishes industrial-tier balance-and-test discipline. The Turbocharger Rebuilding Distribution catalog publishes OE manifest cross-references.

IHI Decision Questions

Who owns IHI turbochargers?

IHI Corporation (formerly Ishikawajima-Harima Heavy Industries, Tokyo, Japan) owns its turbocharger business as part of its broader rotating-machinery and aerospace portfolio. The company is publicly traded on the Tokyo Stock Exchange (ticker 7013). IHI runs turbocharger manufacturing across Japan, Thailand, China, and Hungary, with R&D centers in Yokohama and Stuttgart. The turbocharger business serves both OEM passenger-car applications and industrial diesel platforms.

Which cars use IHI turbochargers?

Subaru WRX / STI (RHF5H / VF-series across multiple generations), Mazda RX-7 (RHB5 / RHB6 in twin-turbo sequential), Nissan Skyline GT-R R32-R34 (RB26DETT factory twin turbos in some variants), Mitsubishi Lancer Evolution (RHF5 / RHF5H on selected generations), Mercedes-AMG GT 63 / S 63 (large IHI K07-class on M177 V8). On the diesel side: BMW B47 / B57 diesels, Mercedes OM651 diesel (alongside Garrett VGT variants), Hyundai / Kia 2.2 CRDi diesel, Nissan YD25DDTi diesel.

Are IHI turbochargers reliable?

OEM IHI turbochargers routinely reach 120,000-200,000 miles when oil-change discipline holds — the same service-life expectation as Garrett, BorgWarner, or Mitsubishi OEM equivalents. The Subaru EJ257 IHI VF-series turbos have a documented Achilles heel: the small-diameter banjo-bolt oil supply line clogs over time, leading to bearing starvation around 100,000-130,000 miles on neglected applications. The fix is a proactive banjo-bolt oil line cleaning at 80,000 miles; with the maintenance done, IHI service life matches the OEM cohort.

What is the IHI VF series?

IHI VF-series turbochargers are the Subaru-specific factory turbo family covering 2.0L EJ20 and 2.5L EJ25 / FA20 applications across WRX, STI, Forester XT, and Outback XT variants. Specific frames: VF22 / VF23 (early WRX/STI), VF34 / VF37 (USDM WRX), VF39 / VF43 (later USDM STI), VF44 / VF48 (current generation). The VF series uses single-scroll inlet configurations with cast aluminum compressor wheels on the OEM-spec frames; aftermarket Subaru-aftermarket VF builds (Stage 2 ports, larger turbines) push the OEM frames toward 350-400 hp targets.

IHI vs Garrett — which is better?

For specific OEM applications, IHI wins by being the OEM supplier; for others, Garrett wins by the same logic. Both brands sit at comparable engineering depth on the OEM side. On the aftermarket performance side, Garrett has the broader catalog (GT / GTX / G-series across 200-2,000+ hp). IHI has narrower aftermarket performance coverage, primarily through Subaru-aftermarket VF builds and selected industrial applications. For most aftermarket buyers chasing power above OEM spec, Garrett, Precision, or BorgWarner are the documented community defaults; IHI is the right cross-shop primarily when staying close to factory IHI OEM spec.

Where do IHI turbochargers ship from?

OEM IHI applications ship through the manufacturer's factory supply chain — Subaru, BMW, Mercedes, Mitsubishi, Nissan dealers stock OEM IHI replacement units at OEM list pricing. Aftermarket-Subaru IHI VF builds ship through performance-tuner distributors (Cobb Tuning, Crawford Performance, AutomotiveTechnik, IAG) at $1,500-$3,500 depending on Stage. Industrial IHI applications ship through fleet-supply distributors (Diesel USA, Industrial Power Products) and OEM heavy-equipment dealers.

Do IHI turbochargers come in compound configurations?

Production OEM compound IHI configurations exist on selected heavy-truck and industrial diesel applications, but not on US passenger-car gasoline applications. Aftermarket Subaru-IHI compound builds are rare due to the EJ257 platform's factory single-turbo architecture; the aftermarket community typically swaps to Garrett, Precision, or BorgWarner frames when targeting compound builds. The four documented twin-turbo factory IHI configurations: Mazda RX-7 13B-REW sequential twin (1992-2002), Nissan Skyline GT-R RB26DETT parallel twin (1989-2002), Toyota Supra 2JZ-GTE sequential twin (1993-2002 Japan-market), and Mercedes-AMG GT 63 / S 63 parallel twin (2023+).