Common Causes of Excessive Oil Consumption

Worried about your car's oil consumption? It is normal for car engines to consume a small amount of oil in the course of operation. What counts as 'a small amount,' though, varies from manufacturer to manufacturer. For instance, a quart of oil in fewer than a thousand miles is considered normal for some BMW engines; for a swath of GM engines, it's a quart every 2,000 miles.However, not all manufacturers provide oil consumption information, normal or otherwise, for their vehicles. In such cases, defer to this rule of thumb: if your engine has less than 50,000 miles on the clock, it shouldn't consume more than a quart between oil changes. If your engine has run longer than that, consumption will be higher. With that out of the way, let us now look at common causes of excessive oil consumption.

Old or Poor Quality Oil

Oil accumulates a considerable amount of dirt, metal bits, and other debris in the course of your engine's operation. If it is not changed in time, the oil starts burning - gets consumed, in other words. And because old oil cannot provide adequate lubrication, your engine runs hotter, which in turn intensifies oil consumption. Poor quality oil has much the same effect.

Synthetic Oils

Synthetic oils generally do a better job of lubricating engines than their conventional counterparts. However, because they have different flow characteristics, they are able to penetrate through chinks that conventional oils cannot. This means you're more likely to experience oil consumption problems with synthetic oils, particularly if your engine is old. However, note that if the seals and gaskets of your engine are starting to deteriorate, your vehicle will lose oil no matter what type you use.

Unusually High Oil Pressure

Higher than normal oil pressure floods the engine with excessive oil. As a consequence, some ends up in the cylinders, where it is burnt up. Unusually high oil pressure is usually the result of adding too much oil during an oil change (a good reason why you should entrust this seemingly prosaic task to a professional) or an incorrect setting on your car's central computer.

Worn or Damaged Piston Rings

If the piston rings of your engine are worn or damaged, oil will be able to work its way into the combustion chamber. The oil will burn, leaving carbon deposits on the rings and cylinders. Worn and damaged piston rings can cause oil levels to drop alarmingly, even over the course of a single day in particularly serious cases, which means you have to constantly top off the oil to keep your engine in good working order.

Closing Thoughts

If oil consumption is minimal - a quart every 1000 to 3000 miles or so, depending on the type of vehicle - you likely have nothing to worry about. However, if oil consumption is excessive, seek professional help as quickly as possible as low oil levels can cause the kind of engine damage that costs an arm and a leg to repair.