Synthetic for a 30 year old engine?

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47
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California
Thread starter
I just purchased a 1989 Camaro with 67k original miles. The owner has serviced the car well, but has always used conventional oil. Can I convert to synthetic or is this going to cause problems? Thank you.
 
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12,441
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Phoenix, AZ
At 30 years old, I don't see the point. Are you going to be putting a ton of miles on it? Unless the gaskets have been changed recently, I wouldn't bother. Although I do run a 1970 VW Beetle on synthetic, but it's already got oil leaks everywhere, it's parked in gravel, and sees very low mileage.
 
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1,627
Location
Cincinnati, USA
Put in conventional oil once. Run it a few hundred miles. Look for leaks and loss of (burning) oil. You can't go by what came in it when sold to you, might just be high viscosity goop meant to quiet the engine. Anyway with the correct conventional in you have a baseline. If seals are leaking, switching to synthetic will probably make it worse with all else equal, but you can use high mileage synthetic with seal conditioners. If the seals are not leaking with conventional oil, do not put high mileage conventional or synthetic in. It does nothing good for seals until they start leaking. If you switch to synthetic and THEN it starts leaking, I'd top it off with high mileage oil and switch to 50% high mileage oil on the next change, not using more of the stuff than needed to keep leaks under control. Shorter answer: Sure it's a good idea to switch to synthetic but don't try to drop down to 5W-20 because the engine is designed for 10W-30 or thicker.
 
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12,782
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ROCHESTER, NY
Yes, you can switch to synthetic oil. Will you have leaking issues? It remains to be seen. Since the engine has been well maintained according to the previous owner, there shouldn't be any sludge in the engine therefore, the synthetic oil shouldn't have any sludge to remove which could cause some future oil leaking! My 38 year old Firebird V8 engine has ONLY used conventional oil all of it's life but, I don't drive it hard. However, with most conventional & high mileage oils now being a synblend, I guess I am using some syn oil.
 
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492
Location
South Wales, UK
Originally Posted by Dave9
Anyway with the correct conventional in you have a baseline. If seals are leaking, switching to synthetic will probably make it worse with all else equal, but you can use high mileage synthetic with seal conditioners. If the seals are not leaking with conventional oil, do not put high mileage conventional or synthetic in. It does nothing good for seals until they start leaking. If you switch to synthetic and THEN it starts leaking, I'd top it off with high mileage oil and switch to 50% high mileage oil on the next change, not using more of the stuff than needed to keep leaks under control. Shorter answer: Sure it's a good idea to switch to synthetic but don't try to drop down to 5W-20 because the engine is designed for 10W-30 or thicker.
Disagree with the high mileage oil. The seals conditioners help to ensure the old seals are elastic and pliable. Regardless of oil leaks or not they're worthwhile on older cars! Agree with the viscosity. Keep the same operational viscosity. I.e. if you're using a 15w40 you could go for Castrol Edge 0w40.
 
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2,213
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Lyndhurst NJ
No need for the syn, Im pretty sure even the conventional will have some syn in it. Id go with a VWB or PYB in 10/40 or so to start, maybe try a high mileage like said. Dont over think it! The car ran on conventional for a long time, Im sure its happy with the same stuff going back in.
 
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1,793
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South Carolina
I changed to sythetic oil in my: 1993 F150 at 182K (now at 255K), 1997 B2500 Van at 160K (now at 175K) and 2000 4Runner at 245K (now at 250K). No leaks. No problems.
 
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844
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California
Sounds like the compromise to meet in the middle of all the suggestions above would be <span style="font-weight: bold">Maxlife Synblend 10w30</span>. It'd be hard for me not to spend the extra couple of bucks and use the full synthetic version though.
 
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1,335
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South Carolina
I switched to synthetic in my 1985 Bronco when it had 217k miles. I ran Amsoil Z-Rod 10w-30 in it until I pulled the engine at 297k miles to swap in a big block. It was run exclusively on Castrol GTX 10w-30 before then. No leaks at all. Quieted a valvetrain tick it had as well.
 
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5,488
Location
Florida
Originally Posted by ka9mnx
I changed to sythetic oil in my: 1993 F150 at 182K (now at 255K), 1997 B2500 Van at 160K (now at 175K) and 2000 4Runner at 245K (now at 250K). No leaks. No problems.
Perfect post. Thank you. My 208,000 mile 17 year old beater didnt leak a drop when I started using synthetic oil when I bought it at 203k. I can't believe that so many keep on posting nonsense about synthetic oil causing leaks to appear. Lol. If the seal is about to start ooozing oil, it's only a matter of time regardless of what oil you use. using SM or SN rated oil (synthetic or not) = the same specs, cleaning power, durability, etc. there's technically nothing different between the oils. The synthetic can simply handle more abuse. What is this, 1990s with old wives tales still going around about "GASP" synthetic oil will cause leaks EVERYWHERE!!!! Ahhhhhhhh!!!!! duh
 
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4,672
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MN
Originally Posted by Artem
What is this, 1990s with old wives tales still going around about "GASP" synthetic oil will cause leaks EVERYWHERE!!!! Ahhhhhhhh!!!!! duh
This 'rumour' going around may have some basis in fact: If there was gunk, gooey junk, sticking to and near the seals, then a modern synthetic oil might be better at getting rid of that sludgy goo, which was actually helping the old seals do their job & seal ! See the 26:00 minute point in the Valvoline Technical Center frank & honest discussion: https://www.youtube.com/watch?v=FXqkOZAkXZw for a better explanation. I'd use a Valvoline Maxlife oil 5w30 in that old car to help the seals get pliable. Or SuperTech High Mileage 5w30, synthetic or conventional. I might favor the full syn versions of those oils, but in this case, any version, conventional, blend, or full-syn will do here, as long as its got the HM's extra seal conditioners.
 
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