fonzy
Well-Known Member
So my pop was asking whether there were any benefits from synthetic oil in the old slant 6. I know there was some problem with cork gaskets in the past? Thanks for the input, I hope this is in the right thread.
synthetic oil?
- Thread starter fonzy
- Start date
-
nm9stheham
Well-Known Member
My dad bought a '76 Dart Lite new and switched it to Mobil 1 Synthetic at 10K miles. I sold it many years later with over 250k miles. The engine had not be touched internally and still read full compression on cylinders. It has very superior lubrication properties and does nto break donw like petroleum based oils. It did not leak.
At that time, there were reports of the synthetics being prone to leaks. It was mostly due to older engines with all the seals and gaskets worn. The full synthetics like Mobil 1 do not have the viscosity changes like petroleum oils over temperature. So, when cold, they stay thin and tended to leak/seep out of older engines when cold. That was when most engines ran on heavier oil weights as standard, like 10W40.
With the newer engines running on 5W20 and 5W30 weights nowadays, the seals and gaksets have to manage lighter oils and the viscosity difference between the common light petroleum oils and synthetics is not nearly as much as it used to be.
I never have seen a problem running synthetics with cork gaskets specifically, and I have run a lot or synthetic oil (but very few cork gaskets in the last 20+ years). Perhaps cork gaskets tend to shrink more and thus have more issues with lighter oils in general?
At that time, there were reports of the synthetics being prone to leaks. It was mostly due to older engines with all the seals and gaskets worn. The full synthetics like Mobil 1 do not have the viscosity changes like petroleum oils over temperature. So, when cold, they stay thin and tended to leak/seep out of older engines when cold. That was when most engines ran on heavier oil weights as standard, like 10W40.
With the newer engines running on 5W20 and 5W30 weights nowadays, the seals and gaksets have to manage lighter oils and the viscosity difference between the common light petroleum oils and synthetics is not nearly as much as it used to be.
I never have seen a problem running synthetics with cork gaskets specifically, and I have run a lot or synthetic oil (but very few cork gaskets in the last 20+ years). Perhaps cork gaskets tend to shrink more and thus have more issues with lighter oils in general?
-
