High Mileage Switch to Synthetic

[SVT_Jeff]

Recently purchased a 95 Cobra with a 124,000 miles on it. Previous owner ran Castrol non synthetic. I run synthetic in all my vehicles and would like to in this one but not sure if it's a good idea with the mileage. I've searched here and on the Amsoil, RP and Mobil 1 website and found nothing definitive on this question. Opinions?

Thank You

 

[oldmodman]

I hope the experts chime in, but personally I would be afraid of starting oil leaks. I don't know if it's just an "old wives tail" but I have always heard that the additive and detergent package in a high end synthetic can remove deposits that are preventing oil weepage at gasket interfaces and even from oil seals.

I do know that I have been using Mobil 1 in my 1992 Ford explorer since new and when I pulled a valve cover the metal was a beautiful golden color and there was absolutely no sludge. But when I yanked the valve cover on a friend's Explorer it was caked with crud. And he had used supermarket dino oil.

 

[SID297]

I hope the experts chime in, but personally I would be afraid of starting oil leaks. I don't know if it's just an "old wives tail" but I have always heard that the additive and detergent package in a high end synthetic can remove deposits that are preventing oil weepage at gasket interfaces and even from oil seals.

I do know that I have been using Mobil 1 in my 1992 Ford explorer since new and when I pulled a valve cover the metal was a beautiful golden color and there was absolutely no sludge. But when I yanked the valve cover on a friend's Explorer it was caked with crud. And he had used supermarket dino oil.

You are correct, I've seen it happen myself.

 

[traktrbeam]

I bought a '99 Crown Vic with a little over 200K on it. Switched it over to Mobil 1 5w-30 2 years ago, still no leaks.

 

[UnleashedBeast]

oldmodman is very correct. A true synthetic didn't actually cause the leak, it simply exposed the imperfections and damage to gaskets and seals that were already there. Darn that superior cleaning ability.

High Mileage lubricants have additives that "swell seals" to decrease leaks. It's something you can try OP. Change to a synthetic lubricant, then monitor oil consumption and leaks over the next 1,000 miles of use. If no consumption or leaks are detected, your seals are in good shape.

 

[SVT_Jeff]

Thanks for the info guys, much appreciated!

 

[lpheaven]

changed to full synth in my dd 2003 mitsu gallant with 130somthingK on it and guess what oil spots in my driveway where i park it and where i NEVER had spots before

 

[deadernie]

I know this wont help you decide but I've got a 96 Explorer 5.0 that I bought with 160K miles on it and now has a bit over 200K miles on it and have been using Mobil 1 in it since I've had it with no problems.

Pretty much the same with my 96 Ranger 2.3. Bought at 170K and now has over 284K. The valve cover weeps a bit but I don't think it has anything to do with the synthetic oil.

Maybe it has to do more with how well it was maintained previously and how much or little sludge was built up as a result of neglect and abuse. I don't know anything about my Explorers history before I got it but I do know the Ranger was well cared for.

 

[ReVviNg HiGh]

I would consider a syn blend hi mileage oil like valvoline max life or full syn max life as the oil has additives that will swell seals to prevent leaks and get the benefit of synthetic additives or full syn oil.

 

[Devcon 7]

Ive switched a high mileage car to synthetic with no problem but for your application look into some brad penn