Synthetic & Seals

[HBCALI]

I've been running Valvoline Synthetic in my Honda for the past few oil changes. The vehicle recently switched from Honda OE oil when I purchased the car from the prior owner (drank Honda oil the whole time prior). However, I'm wondering if the Synthetic is doing anything to keep my seals conditioned. It helps with longer OCI's, but am I shortchanging my seals in the long-run?

Should I switch to a "blend" to ensure my seals get a fair dose of dino to keep them conditioned? How much should I think about this?

 

[mechtech2]

To quote HBCALI:

"I really can't feel the difference between any of them."

New GF5 oils should all be very good to excellent with seal compatibility, with any base stock.
Dino and Syth have neither been historically superior in this regard.

 

[Tom NJ]

No worries. Oil formulations are tested for seal compatibility, so if a synthetic base oil that shrinks seals is used, the formulation will contain a seal swell additive to compensate.

Tom NJ

 

[Pablo]

No worries, synthetic and seal life are grossly over worried here.

My viewpoint: Every car that I inherited (not new) had lived it's life on conventional oil. Most all leaked oil before I got them.

My theory: Dried crusties from conventional oil are much harder on seals than any fresh oil - regardless of base type.

 

[Kestas]

I asked the seal engineers at my company this question. They told me seals arte tested in the lubricant specified by the manufacturer for the application. The fact that someone may decide to use aftermarket synthetic instead of the specified lube is up to the individual. We don't have the resources to test contingent cases.

I hope Tom is correct, that the lube companies test for compatibility. But I don't know how the lube companies can cover or foresee all the different types of elastomers in the market.

Otherwise, I don't think it's a practical concern. Synthetics have been in widespread use for decades in a variety of applications. I'm sure we would have seen bad news rear its ugly head by now.

 

[The Critic]

Originally Posted By: Kestas
I asked the seal engineers at my company this question. They told me seals arte tested in the lubricant specified by the manufacturer for the application. The fact that someone may decide to use aftermarket synthetic instead of the specified lube is up to the individual. We don't have the resources to test contingent cases.

This may be the reason why Toyota recommends switching to synthetic oil at the first oil change (for vehicles that were not originally equipped with synthetic), and recommends that you not switch back to conventional once you switch to synthetic.

 

[pavelow]

Synthetic oils are very common these days, so I'm sure the seals that are put into engines are compatible with them. With that said, even though oil companies say you can switch back and forth between dino and syn, it's best practice to pick one and stick with it.

 

[ChuckBerry]

Why is that "best practice"? What difference does it make?

 

[pavelow]

Why switch back and forth? What's the point? Pick an oil and type and stick with it. That's what best practice means. lol

 

[ChuckBerry]

Why NOT switch back and forth? You haven't defined what best practice means in this context. Why do you advise not switching?

Best practice does not equal habit. Habit can lead you to miss an oil that might work better for your vehicle, or at the very least for your pocket book.

 

[turbochem]

Originally Posted By: pavelow
Synthetic oils are very common these days, so I'm sure the seals that are put into engines are compatible with them. With that said, even though oil companies say you can switch back and forth between dino and syn, it's best practice to pick one and stick with it.


"best practice" based on what exactly?

 

[shadow7]

I heard it's good to stay with one kind. Engines might get used to dino and might not like syn anymore...JMO

 

[toyotapriusguy]

Originally Posted By: pavelow
Why switch back and forth? What's the point? Pick an oil and type and stick with it. That's what best practice means. lol


Because some months one oils on sale and other months it isn't

 

[Kestas]

Originally Posted By: shadow7
I heard it's good to stay with one kind. Engines might get used to dino and might not like syn anymore...JMO

That's a myth. An owner can switch back and forth at will with no down side. How would an engine "not like" an oil if you switch?... what is affected?

 

[Steve S]

Oils are blended to achieve certain charistics as required to pass the specs and all is taken into consideration when blending the add packages and their base oil use.

 

[garlicbreadman]

lol this forum makes people worry too much. honestly, just grab some oil and go.....
dont need to overthink it

 

[ChuckBerry]

If the internet is not for overthinking small decisions and having raging debates over pointless minutiae, what is it for?