• Worn piston rings can cause several problems with your vehicle's operation.Aeronautical piston engine image by Andrew Breeden from Fotolia.com
  
  An engine's piston rings will help keep the engine's compression where it should be and prevent oil from going into the cylinders. Piston rings can wear out from the use of poor-quality gasoline, which leads to carbon deposits or engine knock, as well as from the engine overheating.
  
  

High Oil Consumption

• Broken or worn-out piston rings will lead the engine to burn oil by allowing the oil to leak into the cylinders. If you determine that your vehicle's engine needs oil more often than normal, it could indicate worn-out piston rings. Check the car's undercarriage to find out whether you have an oil leak, which could also explain your engine's constant need for oil.
  
  

White Exhaust

• As the engine's oil leaks into the cylinders and burns along with the fuel, the vehicle's exhaust system will then take the burned oil in the form of smoke all the way through the vehicle's tailpipe. When a vehicle first starts up in colder weather, the exhaust will appear white at first. Constant white or gray exhaust---no matter the temperature outdoors nor how long you drive your car---could indicate worn-out piston rings.
  
  

Poor Performance

• Worn-out piston rings will affect the overall performance of your vehicle's engine and emissions system. Worn piston rings not only leak oil---they allow air to pass through, affecting the engine's overall compression. A lower engine compression will lead to a decrease in power as well as fuel efficiency. The introduction of burnt oil into the emissions system will also increase the amount of pollutants exiting the vehicle's tailpipe, possibly leading to it failing an emissions test.