Check out this engine compression test, leakdown, and bubble tests. Read more only at www.highperformancepontiac.com, the official website for High Performance Pontiac Magazine!

Not all braking systems on semis have to be loud to be effective. Exhaust brakes make a fraction of the noise that compression brakes do, here's how they work.

Diesel engines don’t have spark plugs; instead, they use the super-heated air created by their high compression ratios to ignite the diesel fuel as it’s injected into the cylinder.

Yes, diesels last longer than gas engines, but it's mainly due to its manufacturing. A typical diesel engine is bigger, heavier, and has sturdier components to withstand the higher compression ratios.