The Auto Repair Shop Answer To: What The Heck Does 5W-30 Mean?

Ever Wanted to Asked The Auto Repair Shop…What is Oil Viscosity?

I had a customer come into our auto repair shop in Humble, TX for an oil change. His engine required 5w20 viscosity motor oil. Unfortunately, for my new customer the previous auto repair shop that he went to used the wrong oil, they used 5w-30.
The oil change sticker on his windshield listed a few things on it: The next date and mileage the next oil change was due by, and the viscosity of motor oil that needed to be used.

As technology has been advancing, manufacturers have been using thinner lubricants such as:

  • 10w-30
  • 5w-30
  • 5w-20
  • 0w-20
  • 5w-40

This can be confusing and there are many reasons for this: EPA Regulations, more power, finer tuning, and better gas mileage. Usually, the weight or viscosity of motor oil that needs to go into the engine of your car will be listed on the oil filler lid, if not it is definitely listed inside your owner’s manual.

Many late models have a form of variable valve timing that is adjusted by an electric solenoid that opens and closes, it uses oil pressure to do this. If you are consistently late on your oil changes or using the wrong type of oil, it may cause this valve to malfunction and turn on the “check engine light”.

Too heavy of an oil on cold startup may cause certain parts of your engine to starve for oil. All this will add up and cause problems down the road. If you are not sure which weight or viscosity of oil your engine requires, give our auto repair shop in Humble, TX a call at (281) 883-8362, or visit our Auto Repair Humble website for more information about us.

We have the required capacity and fluid types for your specific vehicle. We will be pleased to have the opportunity to serve you. Armed with this information, you can be confident knowing what to ask for next time you service your vehicle. Thank you for reading our post. Please contact our auto repair company, Specialized Truck and Auto with any questions you may have.