What's the difference between Marine Engine Oil and Automotive Oil? Marine Engines
Although marine engines are generally derived from automotive engines, they are not subject to the same working conditions. In normal conditions a boat's engine is put through much more stress than a car engine. Quicksilver and specially formulated marine grade oils for stern drives outperform automotive oils in almost all marine applications in two key areas: corrosion protection, load and heat resistance.Click Here
to see our range of Marine Grade oils & Lubricants.Corrosion Protection
Typical automotive oils do not contain an adequate level of corrosion inhibitors needed by marine engines. An automotive engine will normally be run every day, whereas a boat engine (especially one used for leisure) will on average only be run once a week or less.
As an engine sits without being run, the oil gradually over time moves from the top parts of the engine into the sump. When an engine is first warmed up its vital that lubrication reaches all the bearings quickly. These bearings must remain protected with additional corrosion inhibitor, such as will be found in a marine environment.
It is true some of the best automotive oils contain high levels of corrosion inhibitor; however marine grade oil is specifically developed with the problem of long periods of immobilisation in mind. Load and Heat
Automotive engine oils need to cope with an extremely wide range of outside temperatures. Marine oil does not need to contain additives to cope with such a wide range of use. It is important that Marine oil stays at a constant viscosity in order to give added protection to bearings when the engine is at maximum working temperature. This is more important than sacrificing protection to allow a freezing cold engine to turn over when temperatures would turn marine grade oil into thick less flowing oil.
To help boaters protect their investment and to ensure a positive boating experience, the NMMA and leaders in the marine industry have developed a four-stroke marine oil certification called FCW.
Products that have the FCW have met minimum testing and quality standards. There are roughly a dozen tests conducted to review viscosity, corrosion, filter plugging, foaming and aeration. In addition, the oil must successfully pass a 100-hour general performance engine test. Engine manufacturers such as Mercury Marine perform additional tests to ensure that our oils exceed these minimum standards. To learn about the NMMA go to www.NMMA.org.
All Quality Marine Grade four-stroke engine oils are FCW certified by the NMMA and are suitable for Marine applications. Quicksilver engine oils are blended from the highest quality oils available in the market. They are continually tested under the most rigorous conditions and must exceed Mercury Marine's minimum standards.Air Temperature
When it comes to marine oils they are designed to cope with a narrower range of outside temperatures than automotive oils. To deal with this viscosity improvers (VIs) are added to automotive oils so they can continue to function at these temperatures.
With marine oils, it is advantageous for the oil to be thicker so VIs are not added.