Kia and Hyundai share many engines, but not all of them
Hyundai rachète 51% de Kia en 1997: résultat, un catalogue de moteurs commun, avec économies partagées, rappels partagés et de nombreux modèles concernés.
By
Graham Pettigrew
In brief
- Kia and Hyundai share many engine families, but the overlap is partial rather than total.
- Shared engines split development and manufacturing costs between the two brands.
- The Nu and Theta II engines led to a 2024 settlement extending warranties to 15 years or 150,000 miles.
- Shared EV parts have brought charging unit failures, recalls and a 15-year/180,000-mile warranty extension.
Many Kia and Hyundai engines are the same, though the overlap is partial. Carscoops reports that the two South Korean brands share a long list of engine families, along with technologies and architectures. Some of those engines have a clean record, and others have produced recalls and a class-action lawsuit.
Why the two brands pool their engines
Kia was founded in 1944 and Hyundai in 1967. After Kia declared bankruptcy in 1997, Hyundai stepped in and bought a 51% stake. Today the pair work like close relatives.
The logic is financial. Sharing an engine lets the companies split development and manufacturing costs without building dedicated supply chains for each brand.
Which engines overlap, and where they are built
The overlap covers diesel, turbo four-cylinder and V6 units, and the shared engines appear in SUVs, sedans and people carriers alike.
| Engine | Where it appears |
|---|---|
| 2.2-liter CRDi turbodiesel inline-4 | Hyundai Santa Fe, Palisade and Sonata; Kia Sorento and Carnival (Santa Fe and Sorento since 2009) |
| Smartstream turbo 2.0-liter inline-4 | Santa Fe, Sonata and K5, mostly in Asian markets |
| Smartstream turbo 2.5-liter inline-4 | Hyundai Sonata N Line, Kia Sorento and several Genesis models |
| Smartstream G3.5 turbo V6 | Shared by both brands; Hyundai also builds a twin-turbo version for Genesis |
The 2.2-liter CRDi is built at Hyundai’s factory in South Korea. Reports suggest the 2.5-liter engine may also power the next-generation Hyundai N cars, though that is not confirmed.
Some shared engines are made in the United States: the Smartstream G2.5GDi and T-GDi, the G1.6 T-GDi and the G2.0 Atkinson. A U.S.-built Telluride, Sportage, Tucson, Santa Cruz or Santa Fe therefore likely carries a domestically made engine. All of them come with a standard 10-year/100,000-mile warranty in the U.S., according to Carscoops.
Reliability: the diesel, and the Nu and Theta II recalls
The 2.2-liter CRDi is generally regarded as solid. Its known weak points are the piezo-electronic injectors, which can cause poor running and expensive repairs, and oil use of up to 0.5 liters per 600 miles.
The bigger trouble came from the 1.8-liter and 2.0-liter Nu and the 1.8-liter, 2.0-liter and 2.4-liter Theta II inline-4s. They were subject to recalls and a large U.S. class-action lawsuit over reports that they can stall, seize and catch fire.
Sharing cuts both ways. When an engine family has problems, vehicles from both brands are likely to be affected. The Nu and Theta II issues touched the 2011-2015 Hyundai Sonata Hybrid, the 2014-2021 Hyundai Tucson, the 2011-2016 Kia Optima Hybrid and the 2011-2013 Kia Sportage, among others.
Shared EV hardware and the charging unit problem
The pooling extends to electric cars. The Kia EV6, Hyundai Ioniq 5 and Ioniq 9, and Genesis GV60 use the 800-volt E-GMP platform with shared battery packs and electric motors. The Hyundai Ioniq 3 and Kia EV4 use a 400-volt version of the architecture.
Several of these EVs have suffered Integrated Charging Control Unit (ICCU) problems. When the unit fails, the car is effectively useless. Lawsuits and recalls followed, and Hyundai extended warranty coverage on affected models to 15 years or 180,000 miles.
For many pairs of related models, the real differences lie in exterior design and interior layout. A buyer who dislikes the look of the current Santa Fe could consider the related Sorento, or choose the Ioniq 5 over the EV6 on styling alone.
Photo: Sergey Meshkov / Pexels
Continue reading
