What is the appropriate RPM when starting a car?
2 Answers
When starting a car, an RPM of 1200-1500 is generally appropriate. Here are the detailed explanations: Higher RPM in cold seasons: During cold seasons, the engine RPM tends to be higher because too low RPM may cause the engine to stall, and a slightly higher RPM helps warm up the engine more quickly. However, during a cold start, the RPM should not be too high either, as the lubricating oil cannot reach the upper parts of the engine. To minimize wear, keeping the RPM below 2000 is advisable. Once the engine stabilizes, the RPM will drop to around 800. Both excessively high and low RPM are undesirable: RPM constantly reflects the engine's working condition. If the RPM is too low, fuel combustion in the cylinders may be incomplete, leading to carbon buildup in the engine, which can cause significant damage over time. Conversely, if the RPM is too high, it can result in greater engine wear.
When starting the engine, I've got some experience with RPMs. During a cold start, like in the morning or winter, the RPM might suddenly jump to 1000-1500 per minute before gradually dropping to the normal range of 700-900 RPM, taking about a minute or two. This is completely normal because the computer automatically increases fuel supply to quickly warm up the engine and catalytic converter. For a warm start, like after parking for an afternoon, the RPM almost immediately settles into the idle range. I've noticed that if the RPM stays unusually high, it might indicate a faulty temperature sensor that needs checking. Regular maintenance to prevent carbon buildup in the idle valve can save a lot on fuel costs. Summer starts show lower RPMs while winter starts are higher - a noticeable difference that's part of the engine's self-protection mechanism. Monitoring tachometer changes helps identify potential issues early.
