2024.01.26 Kia
Experience the Comfortable Ride and Performance of The New Carnival Hybrid with Developers
Kia’s beloved family multi‒seater, the Carnival, returns with a cozy ride and improved driving performance, now complemented by a hybrid powertrain. Especially noteworthy are the efforts dedicated to ensuring a comfortable experience for rear‒seat passengers. The developers share their insights into the enhanced comfort and handling of The New Carnival Hybrid.
The Kia Carnival, a favorite among families, is often said to be the go‒to choice for parents with more than one child. Its long wheelbase, spacious interior with ample seating and cargo space, have not only made it a preferred family vehicle but also a popular choice for ride‒hailing mobility services. It’s truly a modern ‘People Mover,’ optimized for our times.
The New Carnival, upgraded three years after the launch of its fourth generation in 2020, not only features design changes reflecting Kia’s ‘Opposites United’ philosophy but also fine‒tunes its ride for the frequent multi‒passenger use. In response to growing demand for hybrid models, it now includes a hybrid system combining a 1.6‒liter gasoline turbo engine with an electric motor. The New Carnival Hybrid stands out for its excellent fuel efficiency and comfortable ride, enhanced by electric motor‒based driving performance assistance technology.
How was the ideal ride comfort of The New Carnival Hybrid achieved? We explored the secrets behind its snug ride and stable driving performance with Hyundai Motor’s MLV (Midsize‒Large‒Vehicle) Project5 team members.
The secret to achieving a stable ride quality worthy of an ideal family car
Q. The New Carnival Hybrid impressively elevates the level of driving sensation and ride comfort. What was your R&H (Ride & Handling) development direction?
Balancing ride comfort and handling is always challenging, no matter the vehicle. For The New Carnival, we aimed for a balance suitable for a family car – comfortable ride and stable handling. This involved developing new suspension parts and upgrading shock absorber valves, among other enhancements.
Our focus was on minimizing shock and stabilizing body movement over speed bumps and rough roads, reflecting local road conditions. As a result, compared to the fourth generation, The New Carnival offers more stable roll behavior (the degree of body tilt during cornering) and responsive steering. We’ve achieved a ride and driving performance satisfying both drivers and rear‒seat passengers.
Q. Could you explain the features of the newly applied shock absorber valves and their effects?
Previously, the Hi‒Limousine models, known for luxurious rear cabin space, exclusively used special shock absorber valves for enhanced ride comfort. In The New Carnival, we applied these components as standard across the lineup and optimized them. Simply put, shock absorbers use the oil pressure within the piston rod to create damping force, countering unnecessary movement from suspension springs during bumps or cornering. The valve inside the shock absorber controls this oil pressure.
The new shock absorber valves in The New Carnival have been developed with a structure that allows performance tuning, increasing development freedom. This means we can optimize them to our desired direction. As a result, we could achieve both the targeted comfortable ride and stable steering.
Q. Besides upgrading the shock absorber valves, what other improvements have been made?
The New Carnival features bump stoppers attached to where the shock absorbers connect to the chassis. When the weight shifts to the outer wheels or the wheels hit a bump, the shock absorbers compress. The bump stopper prevents over‒compression and damage to the chassis while aiding in shock absorption. Inside the shock absorber piston rod, there’s also an HRS (Hydraulic Rebound Stopper), which absorbs noise and shock when the shock absorber extends.
In the New Carnival, the front bump stoppers have been lengthened to enhance steering stability and reduce pitch motion (the degree of forward and backward movement of the car) when crossing bumps. Additionally, the length of the front HRS and the number of its impact‒absorbing structures were increased to simultaneously improve pitch and roll behavior. In other words, the adjustments have reduced the degree to which the car tilts forward, backward, and sideways, ensuring a more stable ride. The rear shock absorbers are also newly equipped with HRS, achieving more uniform ride comfort and improved ride on rough terrain.
Q. The overall improvements seem to focus on enhancing the rear‒seat passenger experience. Is that correct?
Absolutely. After the launch of the fourth‒generation Carnival, we continuously monitored reviews from top foreign and local media, automotive YouTubers, and real user feedback from clubs. We noticed a high demand for improvements in rear‒seat comfort, especially in reducing body movement over speed bumps and alleviating motion sickness for rear‒seat passengers. To provide a more comfortable and pleasant travel experience, we set the ride comfort development goals for the New Carnival based on our customer feedback.
The Key to Creating an Ideal Family Car’s Comfortable Space
Q. For ride comfort improvement, NVH (Noise, Vibration, Harshness) enhancements are crucial, including reducing noise and vibration. Was this also focused on rear‒seat passengers?
Given the Carnival’s nature of frequently carrying passengers in the rear seats, we deemed rear‒seat quietness crucial. With the newly added hybrid model, where expectations for quietness are even higher, we focused on reducing rear‒seat noise. We extensively reinforced noise absorption materials, especially in the C and D pillars and the interior walls of the trunk area.
We also reduced low‒frequency booming noise, which can be unpleasant and oppressive. Vibrations from the road travel through the tires, suspension, and shock absorbers to the vehicle body, causing noise. At certain frequencies, this noise can be so overwhelming that it hinders conversation between the driver and rear‒seat passengers.
To mitigate this, we improved the reinforcement panels that connect the shock absorbers to the chassis, making them larger and thicker, and applied vibration‒reducing pads more extensively. We particularly focused on reducing noise in the 300‒500Hz range, which corresponds to human speech frequencies. Reducing rear‒seat noise naturally makes conversations more comfortable. Ultimately, the New Carnival achieves a quietness in all seats, making it a fitting space for a multi‒seater family car.
Q. Drivers also experience various unpleasant vibrations and noises. What NVH improvements have been made for the driver’s seat?
A major source of noise for the driver is the wind noise around the A‒pillar and side mirrors. The New Carnival addresses this by sealing gaps around the side mirrors with covers and cutline seals, reducing wind noise. Furthermore, we extended the application of double‒glazed windows to the second row, enhancing interior quietness.
Additionally, in the hybrid model, which uses both an engine and a motor, there are moments when the engine needs to start after driving on motor power alone. We prepared two measures to ensure that this transition doesn’t produce unpleasant vibrations and noise.
Firstly, we optimized the mounts fixing the engine and transmission, as well as the bushes reducing vibration at the lower connection points, to suit the New Carnival Hybrid. Secondly, we adjusted software controls, like engine RPM and the timing of power generation, to reduce the sense of discrepancy during the power transition in hybrid vehicles.
Q. What was the most memorable work in developing NVH measures for hybrid models?
The high‒voltage battery cooling system in our current hybrid models is air‒cooled. The air inlets and outlets for cooling are located under the second‒row seats and in the trunk space for safety reasons. However, this setup led to various issues, such as cooling air discharge noise, thermal sensation, cooling fan booming, and floor vibration. We spent countless hours resolving these issues right up until the release of the New Carnival.
Key efforts included more precise control of the cooling fan, enhancing the sound insulation in the cooling route, and adjusting the cooling air pressure. These developments successfully reduced passenger‒discomforting noise and vibrations. Although using a water‒cooling system, as in electric vehicles, could have resolved these issues faster, it would inevitably lead to higher costs and increased consumer burden. Therefore, it was a task that we devoted ourselves to over a long period with passion and effort.
The New Carnival Hybrid: Comfortable Travel Experience Completed with Electrification Technology
Q. I heard that the powertrain in the New Carnival Hybrid has been optimized to suit a multi‒seater family car. Could you elaborate on this?
The basic configuration is similar to that of mid‒size hybrid SUVs like Kia Sorento and Hyundai Santa Fe. It comprises a 1.6 gasoline turbo engine, a 6‒speed automatic transmission, a drive motor that transmits power and performs driving and regenerative braking functions between the engine and transmission, and an HSG (Hybrid Starter Generator) responsible for engine start and low‒voltage power generation.
However, the New Carnival Hybrid, typically carrying multiple passengers, has been optimized for more stable and smooth acceleration and comfortable shift sensations. Increasing the output (54kW) and torque (304Nm) of the drive motor also aimed at enhancing ride comfort. Consequently, it achieves a system combined output of 245 horsepower and a combined torque of 37.4kgf·m, allowing for a relatively leisurely and abundant performance experience.
Q. E‒VMC (Electrification‒Vehicle Motion Control, a performance assist technology based on the drive motor) is being widely applied to the latest Hyundai Motor Group hybrid models. How has this function been optimized for the New Carnival Hybrid?
E‒VMC technology, common to the latest hybrid models regardless of the vehicle type, is divided into two main functions: E‒Handling and E‒Ride. E‒Handling distributes the vertical force of the vehicle’s front and rear based on the torque of the drive motor, enhancing turning responsiveness and stability through increased lateral force on the front and rear wheels. E‒EHA (Electrically Evasive Handling Assist) is a steering assist function that operates in emergency situations, offering increased responsiveness over E‒Handling. Both focus on the vehicle’s turning motion.
E‒Ride is a feature that enhances ride comfort. Before passing over a speed bump, the drive motor’s deceleration torque reduces the upward movement of the vehicle’s front end. After crossing the bump, motor drive reduces the downward motion. Essentially, this feature mitigates the vehicle’s pitching movement, making for a more comfortable ride.
The Carnival, with its long wheelbase and clear multi‒passenger purpose, focuses on stable vehicle behavior rather than dynamic performance enhancement. Therefore, E‒VMC was optimized to control vehicle dynamics in a stable direction. The E‒Handling feature was incorporated to a degree that enhances responsiveness without compromising driving stability.
It’s crucial for E‒VMC technology to be implemented without causing any discomfort for the driver. If too many functions intervene contrary to the driver’s intentions, it can lead to a sense of fatigue due to the alienation. However, owners of the existing Carnival models will quickly recognize the ride comfort improvement brought by the E‒Ride technology in the New Carnival Hybrid. Passing over speed bumps at a moderate height without pressing the brake pedal, drivers can feel a significant reduction in the vehicle’s pitching movement due to the torque control of the drive motor.
Additionally, the New Carnival Hybrid introduces Hyundai Motor Group’s first ever smart traffic jam assist, adapted for this model. It’s the second application in the Hyundai Motor Group lineup and a first for Kia. This function optimizes shift patterns and motor control in low‒speed traffic conditions based on navigation information and the vehicle’s driving state, preventing degradation of ride comfort due to unnecessary shift operations and helping improve fuel efficiency.
Q. Last question, is there a feature in the New Carnival Hybrid you would highly recommend for potential owners to experience?
Apart from the noticeably improved ride comfort and driving stability, I’d like to mention the newly implemented multi‒zone voice recognition feature in the New Carnival. Equipped with four directional microphones, it can recognize voices not only from the driver’s seat but also from the passenger seat and both left and right second‒row seats, providing functionalities like window operation, seat adjustment, and climate control tailored to each passenger.
Previously, to use voice commands, one had to specify the location like “Open the right front window” or “Turn on the left rear air conditioner.” Now, simply by saying the voice recognition wake word “Hey Kia” followed by the command, the system recognizes the speaker’s location and operates the corresponding function. Notably, it eliminates the need for second‒row passengers to use the ceiling‒mounted buttons for voice commands.
In this way, the New Carnival has undergone a remarkable transformation, not just in its striking design but also in the meticulously crafted ride comfort and the refinement of its driving performance. The first‒ever hybrid model of the Carnival combines even more comfortable ride quality with excellent fuel efficiency, adding diverse appeal. I highly recommend experiencing the new aspects of the New Carnival and the rich charm of its hybrid model for a truly cozy journey.
Photography by Kim Beom‒seok
