The next-generation Hybrid engine design for enhanced efficiency

The 2.5 Turbo Hybrid engine features optimized design, advanced fuel cycles, and precise air-fuel management.

With these innovations, Hyundai and Kia have surpassed 1.5 million hybrid and EV sales in the U.S.

Learn more about how this engine design delivers both performance and efficiency.

*Source: Tech Vision Story

1. Next-generation
Hybrid Engine Design
for enhanced efficiency
2.5 Turbo Hybrid

2. 2.5 Turbo Hybrid Engine

Optimized with dedicated hybrid design, a high-efficiency cycle,
and enhanced air-fuel mixture flow, delivering improved
performance, fuel economy, and regulatory compliance

3. Dedicated hybrid engine design

Decoupling auxiliaries such as the starter and A/C compressor
and directly coupling a P1* motor enables engine to focus on
power generation, enhancing fuel efficiency and performance

*Start, power generation, and drive-assist functions

4. Compression ratio

12.0

Intake valve
closed

e--
Compression ratio

10.5

Over-expansion ratio &
Over-compression ratio

Hybrid-optimized high-efficiency cycle

Higher compression ratiox and delayed intake valve closing
reduce compression losses and maximize combustion energy,
optimizing overall engine efficiency

*Compression ratio: A ratio that indicates how much the piston compresses air inside the engine cylinder

5. Enhanced air-fuel mixture’ flow

Concave bowl-type piston crown improves tumble flow**
and airflow, enhancing combustion efficiency
while reducing emissions

“Air-fuel mixture: The blend of fuel and air inside the engine cylinder
+*Tumble flow: A vertical swirling motion of the air-fuel mixture

Previous 2.5 Turbo

Piston crown

64) 2.5 Turbo Hybrid
N Piston crown

y.

6. At initial start-up Under normal driving
condition

Top Dead Center Top Dead Center

Four-stroke cycle Four-stroke cycle

Bottom Dead Center Bottom Dead Center

2.5L Turbo Hybrid’s fuel injection zone

High-precision 3-stage fuel
injection control

3-stage fuel injection based on intake flow intensity
under driving conditions improves power and
combustion efficiency, even under high-load conditions

7. First applied to Hyundai’s the all-new PALISADE,
this powertrain is expected to elevate its value and
competitiveness in line with the era of electrification