Skip the auto shop - Our mechanics make house calls

Q: Changing oil grades without flushing

asked by on

Can you change engine oil grades from 10-40 to 20-40 without flush?

Sure, all oil is mixable. You can mix synthetic and non-synthetic oil, too. You’ll just want to take most of the oil out when you change it and what is left is mixable. It won’t hurt anything.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. Changing oil grades without flushing

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Service "A" with low tire pressure reading needing scheduled maintenance.

Service A is supposed to be performed after the first year/10,000 miles of ownership, then every 2 years/20,000 miles going forward. This service includes: Oil and filter change Resetting of the maintenance reminder Tire condition/pressure check (this will...

Q: Doesn't $800 seem a little high for an oil pan gasket replacement?

Hello. This is less than an issue about the ethics of a dealership service center, and more about the cost overhead of the 2 different business models (dealership and YourMechanic). A dealership has a much more expensive cost structure: building,...

Q: Car stalls when merging on the freeway.

Hello there. Quite often multiple symptoms will pop up that might be a possible cause of a mechanical defect or problem. I think this is the case here. If you are leaking oil (as you've stated, a lot of oil),...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...