Loss of Horsepower from Wear and Deposits

Many people associate deposits and engine wear with a sudden, disastrous failure of the engine that strands you along the road. The reality is, however, that deposits and wear are more likely to cause a periodic loss of horsepower and decreased fuel efficiency as time passes. Read below to find out how it works and what you can to help fix it.

Horsepower = engine compression

In order for your engine to produce its maximum amount of horsepower, it’s vital that the combustion chamber has to be completely sealed during both compression and combustion strokes. Deposits and excessive engine wear can prohibit the piston rings or valves from properly sealing, which can let pressurized gas escape from the combustion chamber—ultimately resulting in loss of horsepower.

Think of this as a hydraulic floor jack—when you pump the handle, the vehicle will raise so long as the release valve isn’t leaking and is sealed tightly. If the release valve isn’t well-sealed, pressure will escape and the vehicle won’t stay up, regardless of how much you’re pumping the handle.

This same principle also happens in your engine. If any of the compression and combustion stroke pressure releases through poorly sealed piston rings and valves, the engine will deal with loss of horsepower.

During intake, air and fuel enter the combustion chamber on the intake stroke. The next step, compression, can be impacted by deposits and wear due to the fuel and air escaping the chamber. This is caused by full valve and piston ring sealing. The combustion stroke allows pressurized gases to leak through deposit-covered or worn rings and valves, leading to a loss of horsepower.

Deposits and wear can decrease compression

As time passes, valve wear and deposits can inhibit the valves from forming a complete seal. Wear can also impact adequate valve operation, causing a loss of optimal flow. When piston rings become worn or get stuck, the same thing can happen.

These rings are meant to freely move within their grooves and maintain a tight position against the wall of cylinder. Ideally, piston rings form a solid seal that keep the fuel and air in and does not allow it to escape. If the rings are worn, the ideal tight seal will likely be disrupted.

Buildup deposit can lead to rings sticking in their grooves, which can also impact a perfect seal. This can also let some fuel/air mixture escape from the combustion chamber during compression, which leads to a loss of power. Upon the stroke of combustion, pressurized gas can travel from the cylinder wall into the oil sump, taking with it an amount of potential power. This is what’s happening when someone says an engine has lost compression.

Prevent horsepower loss with AMSOIL

AMSOIL Signature Series Synthetic Motor Oil delivers:

  • Up to 75% additional engine protection against wear and loss of horsepower
  • Pistons that are 40% cleaner than what’s required of a double-length industry standard test

The exceptional performance of this oil helps prevent wear and deposits that take horsepower away from engines, and helping to keep the new feeling everyone loves when driving.

To help prove this, we put Signature Series 5W-30 Synthetic Motor Oil in a Ford F-150 with a 3.5L Ecoboost engine in order to test how well it can defend turbocharged direct-injection engines (TDGI) engines from loss of torque and horsepower during extended drain intervals of up to 25,000 miles. Signature Series was able to maintain the performance of the engine across the 100,000 mile test, as evidenced by power sweeps before and after the test.

All in all, one of the best ways to keep horsepower loss at bay is to prevent engine wear and deposits in the first place, to avoid compression reduction. Trust AMSOIL to deliver proven protection for your engine.