changing to synthetic after 150,000k

[know1]

I just bought a 94ss with 150,000k on it, and after talking to the previous owner I found out the it has not been getting either synthetic oil or 94 octane. I have began using 94 whenever I fill up but am about to go get the oil flushed/refilled and was wondering if it was too late to switch to synthetic oil.

Thanks

[ericem]

same question, people seem to think it will make it leak more, but mine doesn't leak or burn, so i guess thats how u debate.

The thing is someone told me once you use full synthetic, you can't go back to normal oil? Is this true?

[dscoobydoo]

The thought behind not going to synthetic after that many miles is that the dino oil will have coated the seals and started to form bonds with the seals and/or possibly filled holes in the seals. By going to synthetic, these bonds will start to break down and you might see more oil being burned or on the ground. Why not compromise and go to a mix blend instead of full synthetic. That is what I use on our SS and we have 152,000 miles on it. No oil leaks here.

[Manarius]

Why exactly is everyone so concerned with going to Synthetics? Dino Oil has worked for the past 50 years, there's no good reason to spend the extra money on Synthetics when the Dino Oil works just fine.

[ericem]

Why exactly is everyone so concerned with going to Synthetics? Dino Oil has worked for the past 50 years, there's no good reason to spend the extra money on Synthetics when the Dino Oil works just fine.

well you do not have to change it as OFTEN, and seems to help on those cold start ups, and most likely offers better lubrication because it is more difficult to break down. Do you have any long term tests in comparison?

My dads truck ran dino oil in the beginning, and on cold starts it would struggle and the HLA's woudl click away, now with synthetic on cold starts, starts much mroe easily, and no more HLA ticking. Maybe even the seals will last longer, anything can happen.

On USMB another guy said he switch all his subi's synthetic(full) and one is his early gen legacy with 180k and he said there were no oil leaks.

[Manarius]

well you do not have to change it as OFTEN, and seems to help on those cold start ups, and most likely offers better lubrication because it is more difficult to break down. Do you have any long term tests in comparison?

My dads truck ran dino oil in the beginning, and on cold starts it would struggle and the HLA's woudl click away, now with synthetic on cold starts, starts much mroe easily, and no more HLA ticking. Maybe even the seals will last longer, anything can happen.

On USMB another guy said he switch all his subi's synthetic(full) and one is his early gen legacy with 180k and he said there were no oil leaks.

So, you're saying that the synthetic oil doesn't get as dirty in the same period of time as dino oil? That doesn't make any sense. If it's lubricating everywhere, it should get just as dirty as dino oil in same period of time. Is the extra cost of synthetic offset by the lower number of times you have to change it?

And, what do cold starts have to do with synthetic vs dino? And, what do clicking HLA's have to do with it either? Clicking HLA's come from them needed to be bled or have something like "Marvel Oil" or whatever put in to quiet them down - not changing to synthetics with chemicals in them that could potentially break down the rubber seals in the engine.

For the average daily driver car, I see no reason to switch to Synthetic Oil. It's a waste of money.

[Splinter]

You dont need to run 94... 91 is fine. Even 89 is good in the winter.

You wont notice any difference between 91 and 94 tho, unless you're tuned for it.

[206er]

Why exactly is everyone so concerned with going to Synthetics? Dino Oil has worked for the past 50 years, there's no good reason to spend the extra money on Synthetics when the Dino Oil works just fine.

less chance of coking in a turbocharger, greater lubricity and resistance to thermal breakdown, etc.
they used babbit bearings for over half a century too, doesnt make those worth running now that superior technology has come around.
and as far as I know, people have been running dino oil in engines for well over a hundred years.