Is it true that you shouldn't put synthetic oil in older cars because the seals in the engine can't handle it?

I have heard you shouldn't put synthetic in older engines because it will hurt the seals, the seals can't handle the thinner oil, and you will develop leaks.





IS this true?Is it true that you shouldn't put synthetic oil in older cars because the seals in the engine can't handle it?
No it's not true.. It's BS, a myth, an old wives tell.





Syn. oil vs. std. oil of the same weight is the same thickness.. A 10W30 in syn, is the same thickness as a 10W30 in reg. oil.





Syn. oil will not hurt seals, or cause leaks.





If fact it's the other way around.. A reg oil will break down and thin out with heat.. Syn oil will not.. It takes a much higher temp to break the syn oil down.Is it true that you shouldn't put synthetic oil in older cars because the seals in the engine can't handle it?
I agree, it is an old wives tale. Another myth is that you cannot mix syn. and conventional oils. If that were true we wouldn't have Durablend or Syntec Blends. Report Abuse

a toyota w/ 58000 miles is barely broken in- do it, man ! youll get 2,000,000,000,000 more miles out of it
well,I am running with synthetic with no problems,at 180,000 clicks.My oil pressure is lower due to the thinner oil,but seems to be ok otherwise
Oh, Synthetic oil is ';thinner';? What crap!!


Syn oil comes in a variety of viscosities, from 5 through 40 (at least).


Consult your operators manual and see if it is OK to use it. My guess is that it is OK%26lt; but check first.
yes running syn. oil is great but if you have a small oil leak it will make the oil leaks bigger because of the lube property's of the oil. it wont hurt the seals they just leak more. i use the oil in my car.it has over 145000 miles . you just need to keep on top of the oil leaks.
the car is already broken in to run an the thicker oil. The synthetic is too thin. you just burn it out the tail pipe.