Fluids and your BMW

Fluids and your BMW

The discussion of fluids for your BMW generates many varying opinions. At Nikolas Motorsport we have used our years of experience and research to arrive at the following standards.

Engine Oils – Most newer BMW engines specify a 5w30 full synthetic that meets BMW long life specs. With the long life specs BMW has extended the recommended oil service intervals to as long as 15,000 miles. Nikolas Motorsport fully believes in this oil specification. However, we strongly encourage our customers to perform oil services at an interval of 5000 miles. This recommendation has been developed after years of seeing higher mileage customer cars suffer from oil related problems. These problems can include annoying (and expensive) high levels of oil consumption, failures of engine components due to sludge buildup, and poor running conditions. Also, cars that do not get inspected as part of a normal oil service often incur higher repair bills since routine repairs are not diagnosed until they have gone an extended period. As a final note on extended oil change intervals, BMWNA has issued multiple Service Information Bulletins (SIBs) regarding the topic of oil sludge build up in the engine. Basically, to be considered for “Certified Pre-Owned” warranty status, many cars must have the valve cover removed to inspect for sludge build-up. Specifically cited in the bulletin are external conditions including city driving, poor fuel quality, extreme temperatures and long oil change intervals, which can cause premature oil aging and premature wear of engine components. It is your choice….regular oil services or take the risk of higher repair bills. This rule applies to all makes and models.

Coolant – Engine coolant is specially formulated to protect an engine from internal corrosion as well as providing the “antifreeze” component. To insure the coolant continues to do it’s job it should be replaced every three years. It should never be mixed with different types of coolant. At Nikolas Motorsport we only utilize factory coolants. For BMWs and MINIs the coolant is a blue color. For the Porsches it is almost a pink color.

Transmission oils and Transmission services – This has been the subject of great debate over the years. In the BMW world, most newer car automatic transmissions are listed by BMW as “Lifetime Fill”. Additionally, BMW lists very specific fluids that differ based on year and transmission manufacturer. In the case of fluids, many shops and many fluid/oil providers suggest one fluid will do for all transmissions. For purposes of this discussion we will treat transmission services and fluid types/specs as two different subjects.

First, lets discuss transmission services. It is important to realize BMW does not build transmissions (automatic or manual). These days most of the BMWs on the road have transmissions built by ZF, although many of the BMWs also have automatic transmissions built by GM. It is interesting to note that there is documentation directly from ZF Technical Services that advises a transmission service at “60,000 miles or eight years”. In the same document they indicate “lifetime is not clearly defined and each OEM (in this case BMW) manufacturer has its own philosophy”. Further, ZF indicates their fluids are “engineered and tested to retain characteristics through normal lifetime operating conditions”. This discussion walks a very fine line. At Nikolas Motorsport we are happy to consult with you to make the right decision for your car. The customer that owns their car, likes their car and wants to put 200,000 plus miles on it looks at things much differently than the customer that has leased a car for three years.

When we do change transmission fluids we always use the factory recommended fluid. With BMWs this can become quite a challenge. To accommodate the transmissions we typically see, this requires stocking as many as five different transmission fluids. There are many people in the industry that claim fluids can be interchanged. At Nikolas Motorsport, our rule is to always use the factory specified fluid.

Differentials, Manual Transmissions and Transfer Cases – Differentials and Manual Transmissions are another component that in some cases (depending on model and year) BMW has specified the unit as “Lifetime Fill”. Generally speaking, that “lifetime” is considered to be 100,000 miles. Depending on the customer, and the car, we will do our best to help you make the correct decision for your situation. Transfer cases are expensive units that enable your BMW, or Porsche, or MINI all wheel drive system to operate. These units require specific maintenance, with specific fluids, depending on year and model. Once again the rule at Nikolas Motorsport is factory specified fluids only.

Brake Fluid – To insure trouble-free operation of your braking system your brake fluid should be changed/flushed every two/three years. By nature, brake fluid absorbs moisture from the air. Moisture turns to steam under hard braking. This can cause the loss of braking performance under conditions where it is most needed. Additionally, moisture in the brake system can damage components over time. If your car is used even as an occasional track car, it will need frequent brake flushes.