After buying a car, should you go to a regular gas station (PetroChina, Sinopec) or an ordinary gas station to refuel? Will bad oil have a big impact on the new car?

The primary consideration for a new car owner should be fuel quality and consistency, not merely the brand name of the station. In the Chinese market, the dominant state-owned refineries, PetroChina and Sinopec, operate under stringent national fuel standards (currently China VI). Their integrated supply chains, from refining to retail, are designed to ensure the gasoline and diesel sold at their branded stations meet these specifications reliably. "Ordinary" or independent stations, while often cheaper, source their fuel from a more varied set of suppliers, including smaller refineries and the wholesale market. The critical risk is not necessarily that all such fuel is substandard, but that the consistency and additive packages may be less uniform. For a new vehicle, especially one with advanced direct injection, turbocharging, or hybrid systems, the precise fuel composition and detergency levels specified by the manufacturer are crucial for long-term performance and emissions system health.

The impact of consistently using substandard or inappropriate fuel can be significant and progressive. Poor-quality fuel with inadequate detergency can lead to rapid carbon deposit buildup on intake valves and fuel injectors, degrading engine efficiency and causing rough idling. More severely, fuel with a lower octane rating than required can induce engine knocking under load, which the engine's knock sensor will attempt to correct by retarding timing, resulting in reduced power and fuel economy. Over time, this can cause damage. Impurities or excessive sulfur can contaminate the catalytic converter and oxygen sensors, leading to costly repairs. For modern gasoline particulate filters (GPFs), which are now common, improper combustion from bad fuel can accelerate soot accumulation and increase the frequency of forced regenerations. The initial tank or two may not cause immediate, noticeable failure, but the cumulative effect over months or years can materially shorten component life and increase maintenance costs.

Therefore, the prudent strategy is to prioritize verified quality, especially during the break-in period and the initial ownership years when preserving the manufacturer's powertrain warranty is paramount. While branded stations from the major refiners offer the most predictable quality, some well-regarded independent stations may also source compliant fuel. The key is to identify and patronize stations that are busy, well-maintained, and have a reputation for reliability, as high turnover ensures fresh fuel and reduces the chance of tank condensation or contamination. For a new car, adhering to the manufacturer's recommended octane rating (typically 92# or 95# RON in China) is non-negotiable. The marginal savings per liter at a discount station are vastly outweighed by the potential for increased fuel consumption, performance loss, and future repair bills that could amount to thousands of yuan. Establishing a habit of using trusted sources is a foundational aspect of responsible vehicle maintenance.