How Motor Oil Affects Horsepower

Heavy sludge  and wear deposits can lead to compression loss

Maybe you heard of Infiniti’s new VC Turbo 2.0 L engine, the world’s first production engine capable of varying its compression ratio. It uses a MultiLink system that ties the connecting rods to the crankshaft and varies piston stroke 88.9 290.1 mm, the difference adjusts 1.2 mm. This effectively allows the engine to achieve any compression ratio between 8.0(for increased performance) and 14.0(for increased efficiency ). Engineers spent 20 years developing this system.

The engine available in the 2019 Infiniti QX 50 and Nissan Altima, marks a monumental leap in technology. Engineers has been more than 100 years chasing the variable compression drain. While research dates to the 1920s, the technology never gain ground. That is until now as automakers search for ways to me tightening fuel economy and emissions requirements.

Operating at the optimum compression ratio for different driving conditions leads to a higher performance while using less fuel. Think of it like transmission gears. The transmission with one gear isn’t nearly as efficient as one with several.

As with any internal combustion engines, however, Infiniti the sea Turbo can only reach its full potential if owners use a quality motor oil. To understand why, we need a primer on engine compression.

At the risk of oversimplifying, engine compression equals engine power. Compression refers to the pressure your engine generates inside it cylinders while running. How much pressure the engine produces and how well it converts about pressure into usable work influence your eight engines efficiency and power.

During combustion, pressurized gases drive the piston down the cylinder to turn the crankshaft. Ideally, all the pressure generated during combustion works to move the Pistons and none of it is wasted as it escapes the combustion chamber. A good analogy is a hydraulic floor Jack. Pumping the handle raise the vehicle as long as the release valve is tightly sealed and doesn’t leak. April sealed release valve, however, allows pressure to escape, causing their vehicle to sink to the ground no matter how much you pump the jack handle.

The same principle applies inside your engine. It pressure created during the compression and combustion strokes escapes pass the stuck piston rings or through worn seals, the engine will create less power.

What might cause the rings to stick or valves not to seat properly ? Wear and deposits. Now you can see how motor oil affects engine compression and power and efficiency.

Let’s start with the piston rings. Most pistons contain three rings, the top two of which are responsible for pressing tightly against the cylinder wall and forming a good seal. Deposits in the ring lands can cause the rings to stick in their groves rather than press against the cylinder wall, creating tiny clearances through which pressurized gases can escape the engine, taking power and efficiency with them. Ring wear can have the same effect.

The same holds true with the valves and valve seals. Worn seals reduce compression, as do heavy valve deposits that don’t allow the valve to seal properly. The result is an engine that slowly loses compression over time and with horsepower.

The antidote to wear and deposits robbing your engine of compression is to use a high-quality motor oil that fights wear and keeps engines clean. An oil like Amsoil signature series synthetic motor oil. We installed signature series 5W-30 in a Ford F150 with a new 3.5L ecoboost engine to test its ability to protect turbocharged direct injection (TDGI) engines from a torque and horsepower loss during extended drain intervals up to 25,000 miles. Power sweeps were done at the beginning and end of the test to evaluate horsepower and torque retention. As the graph shows (outbound link above), signature series helped maintain engine performance throughout the 100,00 mile test. This translate into engine that delivers like new performance for years