LUBRICANTS OILS & ADDITIVES

Subaru lubricants, additives and filters

Although different brands oif oil may look the same, and may serve the same functions, quality can vary enormously. The petroleum industry and the auto industry are vast, and there are any number of shady operators offering cheaper products in an attempt to cash in. That's true of all automotive coolants and lubricants. They serve vital functions and if they fail, the results could be disastrous. Trust only tried and tested products, like the Subaru branded line of fluids.

We recommend consulting the owner's manual for all lubricant specifications including levels, types, and specified service intervals. If you have any doubts about correct lubricants, and the manual can't assist, contact All Drive Subaroo or your local Subaru dealership.

Note: All engine bay fluids are clearly displayed in yellow and should be regularly checked by the owner

Warning: Because of emissions law requirements and the drive to reduce fuel consumption, newer Subarus, and all modern cars, use more oil between services than older models. This means that owners even with brand new Subarus, should regularly check the engine dipstick. Subarus do not have an oil level light or gauge. If levels drop low enough to cause loss of oil pressure, the first warning you get will be the oil pressure warning light, and by then it might be too late to avoid catastrophic engine failure.

Your Subaru depends on a range of fluids and lubricants for smooth operation, ranging from vital engine oils and coolants, to fuel additives and engine cleaners. Subaru engines are built to exacting tolerances and the quality and viscosity of the oils used is critical to reliable operation. Your brake system should only use the best quality brake fluids, and the Subaru boxer engine demands use of particular engine cleaners and additives at regular intervals to ensure smooth operation. Here are a list of the fluids Subaru recommends in servicing your Subaru

Subaru upper engine maintenance (SA 459)

Boxer engines are all prone to heavy carbon build up in the combustion chambers, and Subaru boxer engines are no exception. It's essential to de-coke the Subaru boxer engines (particularly turbo models) at the correct intervals, or a number of running problems arise, including overheating, pre-ignition (knocking), engine run-on, and diminished performance. We at ADS take care of these things on time in our log book servicing schedule, using only Subaru recommended upper engine cleaner products.

Subaru fuel additive (SA718)

Some additives in Australian fuels cause flakes of carbon to fall off the combustion chamber surfaces. Because the boxer engine has its cylinders lying on their sides, when the engine is not running, these particles fall onto the seat of the open exhaust valves and may prevent them from fully closing when the time comes to start the engine. This lowers compression and prevents the engine from starting. The spark plug gets soaked in unburned fuel and this also prevents starting even if the carbon particles becomes dislodged during the cranking. If the engine starts it often runs roughly for a while as the excess fuel is burnt off. Subaru fuel additive, SA718, counters the additive in the fuel and stops the carbon from flaking.

Subaru Engine lubricating oil: two types of oil, many varieties

The different Subaru models and the different petrol and diesel engines have different recommended oils. Oils serve two vital functions: lubrication and cooling. If the oil does not do its job well, the results will be increased engine wear, lower performance, sludge and varnish accumulation inside the engine, and in extreme cases, engine failure. Broadly, there are two types of engine oil; mineral and synthetic. Most commonly the SOHC non-turbo engines use mineral 10W30 oil, and the new FA and FB engines use 0W20 synthetic oil. All EJ turbo engines for standard application use the 5W30 synthetic. It is critical to check the manual for the correct oil.

While Subaru specify oil changes at intervals of 12,500 kilometres, ADS recommends more frequent changes especially with turbo models and city driving.

Subaru Mineral oil

Up until the 1980s oils were all petroleum products, made from the same crude oil from which your fuel is refined. These oils serve their function well enough, to varying degrees, but get dirty very quickly, lose their viscosity quickly, and contribute to sludge build-up inside engines. They also break down under pressure and temperature extremes. This type of oil has to be changed frequently.

Subaru Synthetic oil

With the advent of synthetic oils, many of the problems of mineral oils were solved. Synthetic oil consists of chemical compounds which are artificially made (synthesized) using chemically modified petroleum components rather than whole crude oil. Synthetic oils were developed for aircraft jet engines because they reduce friction and wear on engine parts. Synthetic oil is able to function dependably at the extreme pressures and temperatures of a jet engine and withstand extreme and lengthy engine operation without losing viscosity.

Subaru have developed their own range of synthetic oils as below:

5W30synthetic oil in EJ turbo engines.
5W30 ACEA-C3 special diesel oil for Subaru diesel engines

All Drive Subaroo also recommend that high-output tuned engines, such as the ADS built Cosworth engine, use 10W60 Castrol synthetic We at ADS use only Subaru or Castrol recommended synthetic engine oils for all applications.

The benefits of using genuine Subaru brake fluid include:

• More reliable heavy load brake operation
• No brake fade under heavy braking
• Long service life of cylinders and callipers
• Reduced costs over the life of the vehicle

Premium Subaru transmission fluids deliver benefits in three areas:

Outstanding cold flow properties

• Rapid oil flow to all critical transmission components (i.e. torque converter, friction plates, planetary gears)
• More responsive and comfortable gear shifts. Minimises 'shift shock' when gear shifts occur at low temperature. Reduced torque loss increases efficiency, which means less fuel consumption and lower emissions.

Optimised frictional characteristics

• Smoother gear shifts at all ambient temperatures and load conditions
• Consistent frictional properties improve driver comfort and provide extended anti shudder durability for smooth gear changes

Excellent anti-foam performance

• Ensures proper lubrication and no loss of fluid through breather
• Avoids erratic transmission operation, reduces risk of seizures.
• Superior seal performance
• Helps avoid oil leakages, extending seal life and reducing repair costs

Subaru recommends two different kinds of gear oil, depending on whether it's used in the front or rear diff, with or without LSD. Subaru's premium mineral automotive gear oils are manufactured with modern extreme pressure additives making them suitable for some Limited Slip and all Hypoid type differentials. They can also be used in manual gearboxes, transaxles and transfer cases.

• Gear Oil 75W-90or 80W-90 meets the requirements of API GL-5/6 and MT-1.
• Gear oil LS90 meets AGL-5 performance and is suitable for LSD type rear diffs.

Front diff

The front diff in an automatic Subaru is different in terms of lubrication from the manual. Both are at the front of the gearbox, but in the manual the gearbox shares oil with the front diff, while the automatic transmission and diff use different oils. All autos and manuals come out from the factory with an open hemisphere and use 80W90 gear oil.

Center diff

The center diff is located in the same position in autos and manuals, but operates differently in each case. All manual transmissions share the same 80W90 oil as the centre diff and all autos share the Dexton 3 transmission oil. Oil level in each case is checked using the tranmssion/gearbox dipstick.

Rear diff

There are several different types of rear diffs fitted to Subaru vehicles. The R160 and the FHI diff are most commonly used with or without LSD and use 80W90 gear oil, All STI models that use R180 require special LS90 gear oil.

Like all fluids, it degrades over time and with use, and has to be periodically replaced. There are two types of coolant available for Subarus: Green, and long-life blue. All Subarus from 1991 to 2005, including engines EJ22, EJ20, EJ25 and EZ30 all use the green coolant. Most models from 2005 came with the long life blue coolant.

The green coolant acts as a corrosion inhibiter and anti-freeze and has a service life of around 50,000 kilometres. The blue coolant is more concentrated, and includes Silica. It's good for double the service life of the green coolant and change is recommended at 150,000 kilometres. The two varieties should not be mixed.

Characteristics of the green coolant:

• Protection against cooling system corrosion
• Protection against cavitation in water pumps and hot spots
• Excellent cold weather protection. Subaru Genuine Engine Coolant reduces the risk of coolant freezing and severely damaging engines and/or radiators
• Excellent HOT weather protection. Subaru Genuine Engine Coolant helps prevent engine coolant boiling, leading to coolant loss and possible engine damage
• Replacement at 2 years or 50,000 kilometres, whichever comes first

Characteristics of the blue coolant:

• Improved protection against cooling system corrosion by being specifically designed for Subaru engines
• Suppresses cooling system freezing
• Improved cavitation protection of water pumps and aluminium engine components
• Specifically formulated and recommended for use in Subaru engines from MY09
• Compatible with aluminium, rubber and synthetic components of the Subaru cooling system
• Pre-mixed and ready-to-use
• Replacement at 6 years or 150,000 kilometres, whichever comes first.