We may receive a commission on purchases made from links. While browsing auto repair and maintenance tools at your local parts store, you've likely come across compression testers like the Orion Motor ...

Low- And High-Compression Fuel Economy Engines: The Techniques Are About The Same, But The Approach To Each Is Somewhat Different. A.Most stock cylinder heads have factory-cut undercuts of the type ...

On paper, Nissan's variable-compression turbocharged engine should have been pretty awesome. Since it could change its compression ratio on the fly, it promised the power of a bigger engine when you ...

Compared to the 1960s, the octane content of street-legal gasoline is dismal, to say the least. Today's so-called "high-octane premium" usually is rated at only 92 octane—when you can fine it at all.