China's passenger car market has experienced 26 consecutive years of rapid growth, ushering in an inflection point in 2018. In the "new and old alternation" of traditional fuel vehicles and new energy vehicles, the automobile market has entered a new stage of development. Energy conservation and emission reduction, as a global issue, it has always been lingering on the way forward of major automobile brands.
Looking at the world, the European Union, the United States, and Japan have formulated a series of measures for energy conservation and emission reduction more than a decade ago, including carbon taxation, mandatory carbon dioxide emission reduction, etc., and China has also proposed to reach a control line of 3-4L/100km in 2025. Under this general trend, many car companies actively or passively join the team of optimizing and upgrading the power system, of which the strategy of "engine downsizing" is particularly obvious.
However, in the Chinese market, small displacement engines always seem to be in the undesirable class. In the early 1990s, with a number of cars such as Xiali and Alto, they entered the house, and since then, various discussions about small displacement engines and models have continued to this day.
Until Toyota joins, will the results be different?
01 Dispel worries with technological innovation Toyota is real this time
In 2011, in Changshu, Jiangsu Province, China, when Toyota Motor Corporation President Akio Toyoda Akio announced Chinese that "China is the most important", it marked the official start of the Toyota Motor R&D Center (China) Co., Ltd. (TMEC) project.
As one of Toyota's six global R&D centers, the center is different from Toyota's other R&D centers, TMEC's main role is to adapt Toyota's products to China's local road conditions, and to promote Toyota to launch more models that are more suitable for China's road environment and car environment.
Because of this, Toyota has developed a TNGA 1.5L engine based on the TNGA architecture. Although this engine combines the advantages of driving performance and efficient fuel saving, there are still many challenges in the Chinese market on the issue of engine downsizing. Recently, the author had the honor to come to the Toyota TMEC R&D Center in Changshu to take this opportunity to understand what Toyota's strength lies.
For the TNGA 1.5L engine, the common concerns of domestic consumers are concentrated in the introduction of new technologies, five or even ten years later, whether there will be problems such as increased jitter, decreased retention rate, weakened power, and increased noise. To this end, Toyota engineers specially took two pieces of engine shock absorbers that have been running for 10 years, and installed them on the 2021 1.5L Corolla and the 2021 1.5L Ralink car to simulate long-term and long-distance use scenarios.
(New shock absorber bracket for new cars)
(Old car aging shock absorber bracket)
In the static experience, the engineers increased the engine speed of the two cars to 3000 rpm, thanks to the addition of a three-layer sound insulation structure on the inside of the engine compartment, and the addition of a layer of EPDM sound insulation coating to the engine surface, so as to further reduce the noise transmitted by the engine to the car and improve the quietness of the vehicle. Judging from the decibel measurement data, the noise change of the two cars is not large in the case of the speed being gradually increased.
(2021 1.5L Corolla Static 2000-3000rpm Decibel Meter Test Data)
(2021 1.5L Ralink Static 2000-3000rpm Decibel Meter Test Data)
Engineers then increased the speed to 3000 rpm and used a vibrometer to test the jitter inside the vehicle. In response to vibration problems, in addition to the conventional balance shaft, Toyota has also improved the parts inside the TNGA 1.5L engine to reduce the sense of idle jitter. At the same time, the impeller weight block and spring device are added in the torque converter to form a dynamic damping block, which further reduces the vibration level of the engine, so we can see that at high speed, the value of both vehicles is maintained at about 0.1mm/s.
(2021 1.5L Corolla Static 2000-3000rpm Vibrometer Test Data)
(2021 1.5L Ralink Static 2000-3000rpm Vibrometer Test Data)
In terms of dynamic experience, the powertrain of the TNGA 1.5L model can bring a smoother driving experience, while the maximum horsepower of 121 horses will not appear to be very slow in straight-line acceleration, coupled with the advantages of lightweight and low center of gravity under the TNGA architecture, it can still give the author a good driving pleasure. At the same time, the two models of test drive, the jitter and noise perception from the engine are not obvious, but more from tire noise and wind noise.
02 Engine downsizing What is Toyota's strength?
In view of the engine downsizing strategy, American cars have already "withdrawn the key" at the point, while Japanese cars have "sent the key" at the point, and improving the value of small-displacement models has become a key consideration for Japanese brands, including Toyota.
The TNGA 1.5L engine on the new Corolla and Ralink is technically different from the previous competitors. Toyota's TNGA 1.5L engine is based on the TNGA architecture and is based on the current main engine for modular development, just like the 500cc single-cylinder module, as well as the 80.5mm x 97.6mm bore and long stroke, and its own 2.0L, 2.5L naturally aspirated engine technology is compatible.
In addition, the TNGA 1.5L engine oil supply method has become direct injection in the cylinder, and the compression ratio has risen to 13:1, reducing heat loss while improving the thermal efficiency of the engine to 40%, and compared with other newly developed engines, the stability is more secure.
As for the NVH level, Toyota has adopted the expansion of the contact surface of the engine and the gearbox, so that the powertrain rigidity of the 1.5L engine is 6% higher than that of the 2.0L/2.5L powertrain, while optimizing the stiffness of the main components such as the cylinder block, cylinder head, crankcase, timing chain, etc., and the resin process with better shock absorption effect used in the balance shaft driven gear, so that the engine can achieve better NVH and lightweight, so that the same displacement is the lightest, so in the actual measurement experience, In order to achieve such excellent performance.
03 Maybe the best times are coming
It is undeniable that environmental protection and electrification are the core trends of the automotive industry in the future, but electrification is a long and gradual process, new energy vehicles still need a long time to completely replace the internal combustion engine, and under the premise of accelerating the environmental protection process, engine downsizing has become a bridge for cars to electrify.
With the advancement of technology, this type of engine is becoming more and more perfect, there is no doubt about this. Implemented at the user level, combined with the "2019 Small Displacement Engine Market Trend and Usage Satisfaction White Paper", it is not difficult to find that in the domestic market, there are obvious differences in cognition between potential users who have not experienced small displacement models and real owners, in other words, there are still many consumers who have "misunderstandings" about small displacement engines and models.
At the same time, in the retention rate that many consumers are concerned about, some data show that the three-year vehicle retention rate of Toyota brand TNGA models in 2021 continues to rise, taking the statistics of September this year as an example, in terms of the 3-year vehicle retention rate of the joint venture brand, the retention rate of Toyota brand TNGA models reached 86.4%, an increase of 1.9% over August.
When we look back at Toyota, the world's most prestigious car company, choose to believe in small displacement models, perhaps the best era of small displacement engines is about to begin.