Core Viewpoint - The internal combustion engine market in China shows a mixed performance with a decline in month-on-month sales but a year-on-year growth, indicating ongoing market activity despite short-term fluctuations [1][3]. Internal Combustion Engine Sales - In April 2025, domestic internal combustion engine sales reached 4.4562 million units, a month-on-month decrease of 7.88% but a year-on-year increase of 11.92%. Cumulative sales from January to April totaled 17.4872 million units, reflecting a year-on-year growth of 17.37% [1]. - The multi-cylinder diesel engine market, closely related to the commercial vehicle sector, experienced a decline in both month-on-month and year-on-year sales, with April sales at 174,600 units, down 16.45% month-on-month and 1.54% year-on-year [1][16]. Diesel Engine Performance - In April 2025, diesel engine sales amounted to 480,000 units, showing a month-on-month decline of 11.75% but a year-on-year increase of 5.34%. Cumulative sales for the first four months reached 1.8485 million units, up 4.29% year-on-year [3]. - The multi-cylinder diesel engine sales for January to April totaled 1.5 million units, with Weichai leading the market with over 270,000 units sold [6]. Commercial Vehicle Market - In April, the production and sales of commercial vehicles were 362,000 and 367,000 units respectively, reflecting a month-on-month decline of 16% and 17.9%, but a year-on-year increase of 1.3% and 2.7% [7]. - The multi-cylinder diesel engine sales in April were 380,800 units, down 14.09% month-on-month but up 3.72% year-on-year, with cumulative sales for the first four months at 1.5049 million units, a year-on-year increase of 2.99% [7]. Company Performance - In April, Weichai maintained its position as the top seller of multi-cylinder diesel engines with 60,800 units sold, while Yuchai and Yunnei followed with 57,100 and 35,900 units respectively [9]. - Cumulative sales data for January to April shows Weichai with 273,900 units sold, holding an 18.20% market share, while Yuchai sold 202,900 units with a 13.48% market share, reflecting a year-on-year growth of 20.78% [11][19]. Market Trends - The multi-cylinder diesel engine market experienced a notable month-on-month decline in April, contrasting with the year-on-year growth trend, raising questions about future performance in May [23].