Engine Oil Filters

Choosing the Right AMSOIL Engine Oil Filter

An engine oil filter removes contaminants carried through the lubrication system before they can continue circulating through bearings and other critical engine components. Filter selection involves more than finding a filter with the correct thread or physical dimensions: filtration efficiency, contaminant capacity, construction and intended service interval can all differ between filter families.

AMSOIL offers several engine oil filter ranges for passenger vehicles, motorcycles and heavy-duty applications. The correct filter should first be selected by application, then by the level of filtration and service capability appropriate for the vehicle.

AMSOIL Engine Oil Filter Ranges

Filter fitment must always be confirmed for the particular engine. Filters that appear physically similar may use different threads, sealing dimensions, bypass-valve settings, anti-drainback arrangements or internal construction.

Ea15K vs EaO Oil Filters

Ea15K and EaO filters serve many of the same broad passenger-vehicle applications, but they are designed around different service requirements.

AMSOIL Ea15K Oil Filters provide high-quality filtration for motorists using more conventional oil-change intervals. Their 15,000-mile product designation provides substantial service capability without requiring the extended-service construction of the premium EaO range.

AMSOIL EaO Oil Filters are the premium extended-service option, with a 25,000-mile product designation and filtration designed around longer oil and filter service where the application and maintenance program permit it.

If the filter will be replaced at relatively conventional oil-change intervals, Ea15K may provide the more straightforward choice. Where an application uses an appropriate extended-drain maintenance program and an EaO filter is available, the additional service capability of EaO may provide greater value.

Does a 25,000-Mile Filter Mean I Should Drive 25,000 Miles Between Oil Changes?

No. A filter's service capability does not by itself determine the correct engine-oil change interval.

Oil-change intervals depend on the lubricant being used, engine requirements, operating conditions and applicable manufacturer or lubricant recommendations. Severe service, contamination, fuel dilution, engine condition and other factors can also influence appropriate maintenance intervals.

A long-life filter provides the capacity to support extended service where appropriate; it should not be treated as permission to disregard the vehicle's lubrication and maintenance requirements.

Filtration Efficiency and Contaminant Capacity

An oil filter must balance several requirements. It needs to capture damaging particles while allowing sufficient oil flow through the engine across changing temperatures and operating conditions.

Filtration efficiency describes a filter's ability to capture particles of a specified size. Capacity describes how much contamination the filter can hold before restriction becomes excessive. Both matter when evaluating a filter intended for extended service.

A filter that captures fine contaminants but has insufficient capacity for its intended service interval can eventually become restricted, while simply increasing flow without effective filtration would compromise contaminant removal. Filter design therefore involves a balance between efficiency, capacity and oil flow.

Why Oil Filter Construction Matters

The filtration media is only one component of an engine oil filter. Depending on the application, the filter can also contain an anti-drainback valve, bypass valve, centre tube, end caps, sealing components and a housing designed to withstand engine oil pressure and temperature.

The bypass valve is particularly important. If oil cannot pass through the filtration media quickly enough — such as during very cold operation or if a filter becomes excessively restricted — the bypass system can allow oil to continue reaching the engine rather than starving critical components of lubrication.

This is one reason an oil filter should be selected by correct application rather than simply choosing another filter that happens to screw onto the engine.

Motorcycle Oil Filters

AMSOIL EaOM and EaOMC Oil Filters are designed for compatible motorcycle applications. The two families also allow the filter appearance to suit different motorcycles.

EaOM filters use a black exterior finish, while EaOMC filters provide a chrome finish for applications where the oil filter is visible and appearance forms part of the motorcycle's presentation.

Filter fitment remains application-specific regardless of finish. Use the correct AMSOIL filter number for the motorcycle rather than selecting a filter by appearance or dimensions alone.

Heavy-Duty Oil Filters

Heavy-duty diesel engines and commercial equipment can place different demands on filtration from typical passenger vehicles. Large oil capacities, extended operating periods, high engine loads and commercial duty cycles all influence filter requirements.

AMSOIL EaHD Heavy-Duty Oil Filters are intended for compatible heavy-duty truck and equipment applications requiring an appropriate full-flow engine oil filter.

For commercial equipment, filter selection should be based on the engine application and maintenance program rather than substituting a passenger-vehicle filter that appears dimensionally similar.

Full-Flow vs Bypass Filtration

The engine oil filters shown in this category are primarily part of the engine's full-flow filtration system. Full-flow filtration is designed so the engine's lubricating oil supply passes through the filter while maintaining the flow required by the lubrication system.

Bypass filtration is a different concept. A bypass system diverts a small proportion of the oil through an additional high-efficiency filter before returning it to the engine. Because only part of the oil flow passes through the bypass filter at any one time, it can target much finer contamination without restricting the engine's primary lubrication flow.

For information about auxiliary filtration systems and replacement bypass filters, see our Bypass Filtration range.

Find the Correct Oil Filter

Oil filters should always be selected by vehicle or engine application. Do not assume that filters with similar dimensions or mounting threads are interchangeable.

Use the AMSOIL Vehicle Product Finder to identify compatible AMSOIL engine oil filters for supported cars, four-wheel drives, motorcycles and other applications.

If an AMSOIL filter is not listed for your application, contact AMSOIL Australia with the vehicle or equipment details before attempting to cross-reference a filter based solely on dimensions.