Core Viewpoint - The article discusses the rapid increase in engine thermal efficiency in recent years, particularly among domestic hybrid vehicles, raising questions about the validity of these claims and the methods used to achieve them [1][3][5]. Group 1: Engine Thermal Efficiency - Engine thermal efficiency is a critical parameter that directly affects fuel consumption, with historical improvements being slow and challenging, taking decades to achieve significant gains [1][7]. - Recent advancements have seen thermal efficiency figures leap from 43% to as high as 48%, leading to skepticism about the authenticity of these claims and the methods employed by manufacturers [3][5][13]. - The article highlights that achieving thermal efficiency above 40% is complex and requires advanced engineering, with examples like Mazda's compression ignition engine and F1 engines showcasing the challenges involved [11][13]. Group 2: Marketing and Misrepresentation - Some manufacturers are accused of manipulating test conditions to present inflated thermal efficiency figures, undermining genuine research and development efforts [5][16][22]. - The article compares the current situation to past marketing tactics, where companies focus on peak performance metrics rather than overall efficiency, leading to a misleading representation of their products [18][20][22]. - The trend of emphasizing maximum thermal efficiency as a marketing tool detracts from the actual engineering challenges and complexities involved in improving engine performance [24][25]. Group 3: Industry Implications - The competitive landscape has shifted towards marketing gimmicks rather than substantive technological advancements, potentially harming companies that invest in genuine R&D [23][25]. - The article calls for a more honest approach from manufacturers regarding thermal efficiency, suggesting that consumers value reliability and quality over mere numerical superiority [25][27].