Synthetic bad for seals ? Long Run

[Ndx]

Quote:
I've heard that synthetic oil can adversely affect my seals. Does Auto-Rx® help?
A: We believe that high-mileage engines using synthetic/semi-synthetic or high mileage oil weaken the seal material and it loses its pliability.


so running synthetic oil is bad for seals ?

 

[firemachine69]

Notice the "we believe" part?

 

[fred]

Funny how old rumors never die.

 

[ZZman]

Any high mileage engine may suffer from seal issues. Synthetic is not the issue. When Synthetics first came out there were issues with seal material that have long since been fixed.

 

[bmwtechguy]

While the above post may be true, it is still possible that using synthetic oil in an engine that used mineral oil all its life may begin to leak oil. I find this is true the older the engine is (older seal material?), and the worse the maintenance practices (infrequent oil changes). Also, in my experience, the group III type synthetics have been less likely to leak than some of the others. FWIW.

 

[VK56VD]

I'm sure the new synthetic oils, especially group III oils are fine for seals.

What I am having trouble understanding is people that use a quality high mileage oil such as MaxLife are on a route to seals weakening due to the seal conditioners and swelling. Can I assume there are bad long term effects of using High mileage oil all the time?

I know some have reported using MaxLife in new/newer vehicles and never had problems. Will the problems occur sooner in older vehicles?

 

[ZZman]

I guess it depends on what you mean by "in the long run". Most people don't keep their cars for very long so it would depend on how long or how many miles you keep the vehicle. For most people this is a none issue. Most people could run 100-200,000 miles with no issues. Some probably will have issues in that amount of time.
In which group you might fall, who knows?

 

[harry j]

Originally Posted By: Ndx
Quote:
I've heard that synthetic oil can adversely affect my seals. Does Auto-Rx® help?
A: We believe that high-mileage engines using synthetic/semi-synthetic or high mileage oil weaken the seal material and it loses its pliability.


so running synthetic oil is bad for seals ?



I have been running Amsoil 0w30 in 1993 Civic for over 135,000 miles, no leaks.

 

[dan3952]

Perhaps there is something that happens, in an old engine, in the process of going from a *MaxLife* synthetic oil back to a regular dino oil.. as I just did. If the Max Life formulation causes the seals to swell up like a raisin to help them stop leaking, they might go back the way they were after a regular oil is put back in. I don't know how many of my seals have cracks in a 10 year old engine, but I can't imagine this scenario helping the situation any with regard to wear on rubber parts.

Also I don't know why people use the MaxLife with new cars.. I have 211,000 km on my 2.3 and it leaks and burns oil.. and at that point the MaxLife use helped a bit but didn't cure either problem.

Originally Posted By: Spartuss
I'm sure the new synthetic ils, especially group III oils are fine for seals.

What I am having trouble understanding is people that use a quality high mileage oil such as MaxLife are on a route to seals weakening due to the seal conditioners and swelling. Can I assume there are bad long term effects of using High mileage oil all the time?

I know some have reported using MaxLife in new/newer vehicles and never had problems. Will the problems occur sooner in older vehicles?

 

[FrankN4]

I have 204,000 miles on a 1999 Chevrolet Cavalier that got Mobil 1 15W-50 the minute I got it home from the dealer. No leaks or no oil consumption of any kind.

I have a 1986 Toyota pickup that has 250,000 miles on Mobil 1 15W-50. No leaks and no oil consumption.

I don't know if these qualify as "older engines" but there has been no problems for 18 years on synthetics.

I can remember when synthetics first began to gain popularity. One of the discussions was that the "new" synthetics would clean deposits from the engines that had been running on conventional oils. These deposits would be on the seals also. As the seals were cleaned, the synthetics would penetrate the seals and and seep. Now the synthetics have seal conditioners and even the HM conventional oils have seal conditioners. The irony is that the seal conditioners are actually a group V synthetic.

There is also a thread on here, somewhere, I can't find it, that says that in the last few years seals have been made from a material that is not sensitive to nor do they need seal conditioners.

 

[buster]

BeeS. Fully synthetic oils contain esters that increase seal swell and make seals more pliable, not less. They also keep engines more clean which helps prolong the life of engine seals.