
usewith refers to the forced activation of the air conditioner's powerful defrosting mode, switching the air circulation to external mode, and directing the airflow towards the front windshield. Below is a detailed introduction to 'usewith': usewith operates together with the external circulation mode, indicating that the air outlet mode is selected for both eye-level vents and windshield vents, which can accelerate the dissipation of fog on the windshield. External circulation in the air conditioning system means drawing air from outside the vehicle, directing it through the air conditioning system for heating or cooling, and then blowing it out through the vents, thereby replenishing fresh air and improving the air quality inside the vehicle. Although continuous internal circulation can lower the temperature inside the car, the carbon dioxide exhaled by passengers will increase. It is recommended to switch to external circulation every hour to refresh the air.

I checked, and the term 'usewith' is really uncommon in the automotive field. I think you might have made a typo. I guess you meant 'use with' (to be used together with something). For example, when it comes to engine oil, you must pay attention to the correct specifications, such as 5W-30, which must match specific engines. Once, my friend mistakenly put diesel engine oil into a gasoline car, and the engine seized immediately. Some additives also require attention—fuel system cleaners, for instance, must be specifically designed for direct injection or port injection engines. The maintenance manual actually explains all this clearly. I recommend checking the manual for compatibility before replacing any parts to avoid unnecessary repair costs later.

Last time when I got my car repaired, the mechanic mentioned something about parts compatibility, which is probably what you're referring to. Simply put, some car parts must be used in matching sets. For example, if you upgrade the brake calipers, you must also replace the brake discs with the corresponding size. My neighbor tried to save money by pairing aftermarket parts with original brake pads, and ended up with severe brake noise. Turbocharged cars also require higher-grade engine oil, as mixing can easily lead to insufficient lubrication. Tire and wheel sizes must match as well—I once saw the ridiculous case of 19-inch wheels fitted with 17-inch tires. Remembering the OEM part numbers is crucial; when buying parts, providing the car model and year is always the safest bet.

I understand this term refers to accessory compatibility requirements. For example, upgrading to xenon headlights must be paired with projectors, otherwise the scattered light will blind oncoming drivers. Mixing coolants is even more dangerous - combining different colors can form a gel-like substance that clogs the pipes. Most crucially, never mix DOT4 and DOT5.1 brake fluids as their different boiling points may cause brake failure. Always check official compatibility lists before modifications - BMW's ISTA system, for instance, can verify part compatibility. When in doubt, visit an authorized dealership. Though more expensive, it saves hassle.


