How to Mix STP & Mobil 1

Regular maintenance on your automobile is the keystone to a vehicle with a long life. Included with regular maintenance is the ubiquitous oil change. Synthetic motor oils, such as Mobil 1, claim to protect the engine and increase fuel economy. Oil treatments such as STP brand make similar claims. STP suggests mixing its oil treatment with Mobil 1, while Mobil 1 claims it is not necessary. Though the combination is not likely to hurt your engine, you will have to choose whether it benefits your vehicle or your pocketbook.

Things You'll Need

  • STP Oil Treatment
  • Mobil 1
  • Funnel
  • Change the oil of your car. Though STP Oil Treatment can be added at any time, it is best when added to a vehicle with clean oil.

  • Add the amount of Mobil 1 to your engine as recommended by your car manufacturer. Use the funnel to prevent spilling the oil.

  • Turn on the car and let it idle until the engine is warm. Use the temperature gauge in your car to determine when the car is warm.

  • Turn off the car. Add one bottle of STP Oil Treatment to the oil if your car is a six- or eight-cylinder, or half a bottle if your car has four cylinders. Pour the STP in the same place that you pour the oil.