What is the compression pressure of a gasoline engine?

[VonMalia]

The compression pressure of a gasoline engine is between 9 and 12 bar. Typically, engines with low compression ratios are below 10 bar, while those with high compression ratios exceed 10 bar. Older gasoline engines have compression pressures ranging from 6 to 10 bar. The compression ratio of a gasoline engine refers to the degree to which the engine's air-fuel mixture is compressed, which is the ratio of the total cylinder volume before compression to the cylinder volume after compression. The volume formed by the engine piston moving from the lowest position to the highest position represents the smallest volume during the entire piston stroke. The compression ratio to be calculated is the ratio of the maximum stroke volume to the minimum volume.

[SophieFitz]

I think the compression pressure of a gasoline engine is a pretty critical indicator, usually ranging between 120 and 180 pounds per square inch, but this depends on the engine's specific design and condition. For example, a naturally aspirated engine with a compression ratio of 10:1 would have a pressure around 130 psi; if the compression ratio reaches 12:1, like in some high-performance cars, the compression pressure would be higher, possibly up to 200 psi. Low compression pressure is not a good sign—it could indicate worn piston rings or poor valve sealing, leading to cylinder leakage, reduced engine power, and increased fuel consumption. Personally, I make it a habit to use a simple pressure gauge for a quick check during maintenance. If it's below 100 psi, it's time for immediate inspection. Regular checks like this can prevent major overhauls and keep the engine running efficiently, which is especially important when driving older vehicles.

[StBraxton]

After years of driving, I've noticed that gasoline engine compression pressure typically ranges between 130 to 160 psi. If it's too low, the engine feels sluggish and acceleration becomes slow. During my last check, my car was at 150 psi, which is still normal. However, if it drops below 100 psi, there might be internal cylinder issues, requiring repairs to the pistons or valves. Compression pressure affects fuel consumption and noise levels, with normal pressure ensuring smooth engine operation. Simply put, when checking, car owners should refer to the manual standards—most vehicles should maintain at least 120 psi. Don't overlook this small detail, as it's crucial for long-distance travel reliability. Using good quality engine oil regularly also helps protect the engine.

[StLorenzo]

I've used a tool to measure compression pressure. For gasoline engines, it's generally between 100 to 180 psi. The steps involve unscrewing the spark plug hole, inserting the pressure gauge, starting the engine, and reading the value. If the reading is too low, say below 90 psi, it indicates air leakage, possibly due to cylinder wall wear or gasket issues. If it's too high, it can lead to knocking. For regular cars, around 130 psi is ideal; too high can damage the engine. Regular testing helps detect faults early, saving money and hassle.