In the context of “carbon neutrality and carbon peaking”, the decisions of car manufacturers as producers are related to the achievement of low-carbon emission reduction targets. This paper investigates the impact of consumers’ brand perception weight and energy-efficient product preferences on the R & D of energy-efficient technologies in a duopoly based on the energy-efficiency utility degree, using the Hotelling model, and analyses four strategies: no R & D by both parties, R & D by only one party and R & D by both parties. It was found that the level of R & D, profits, market demand and prices were all optimal when only one party had developed. When one party is already devel-oping, the other party’s preference for energy-efficient products and the size of the low-carbon market must be taken into account, and when both parties are developing together, the level of technology is related to their location. Recommendations are made in response to these findings.