Skip the auto shop - Our mechanics make house calls

Q: Synthetic oil

asked by on

Just bought this car from dealer. Is it safe to run synthetic oil in it. 9 years old with only 75000 on it when I bought it. Any risk of causing oil leaks?

My car has 80000 miles.
My car has an automatic transmission.

A: At your next oil and filter change you shou...

At your next oil and filter change you should definitely use synthetic oil. Although existing leaks will leak at some greater rate when using synthetic oils versus purely mineral based (aka, "conventional" oil), the amount is meaningless in most seal locations and in most circumstances. The potential for a leak is due to the smaller size of the molecules in synthetic versus conventional oils. However, synthetic oil cannot possibly cause or otherwise mechanically enlarge a leak. In any event, any "distinction" is meaningless simply because if you put synthetic oil in a car and you can see a leak from a seal it was most decidedly leaking anyway with regular oil and so would have to be repaired regardless of the oil "type" you are using.

In your specific case, with a relatively newer car and low miles on the engine, this possibility of a leak is probably not at least for a while, although you are getting close to the time frame when just due to rubber aging (over time, not mileage related), leaks will start developing anyway. The bottom line is you can and should use synthetic oil in your circumstances due to its huge advantages in physical properties and potential to lengthen the service life of your engine and even seemingly unrelated parts like oxygen sensors and the catalytic converters (synthetics don’t have the sulfur and other elemental contaminants that mineral oil has).

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!

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: how do you install spark plugs

Hi there, thanks for writing in. The quick and easy rundown of replacing your spark plugs is to carefully remove the spark plug wire from each spark plug, being sure to mark each one so you remember where they go...

Q: Oil leaking all out under front end

It sounds like the oil pan ruptured or tore from an impact. The crankshaft is above the pan and probably is not damaged however there is an oil pick up tube and screen assembly in the lower oil pan area...

Q: Air conditioning not working

The AC system has many components that may be the cause of it blowing warm. The most common failure is the AC compressor leaking out of the front seal. It could also be an internal failure, such as a leak...

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 Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...