oil
Pro
Joined: Nov 2011
Posts: 542
Likes: 2
From: Miami FL
I believe the factory recommendation for 86 is 5W30 dino oil...
You will not hurt it going to full synthetic, but you probably want to stay with the recommended thickness for start up protection. It is probaby way overkill for your needs in a street driven car.
You might see increased leaks with Synthetic oil though; depending on your mileage and current oil leaks. Mobil 1 has a high mileage synthetic oil that is actualy meant to help with oil leaks in high mileage cars.
You will not hurt it going to full synthetic, but you probably want to stay with the recommended thickness for start up protection. It is probaby way overkill for your needs in a street driven car.
You might see increased leaks with Synthetic oil though; depending on your mileage and current oil leaks. Mobil 1 has a high mileage synthetic oil that is actualy meant to help with oil leaks in high mileage cars.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
FYI; LORE, from the older days of synthetic oils. If you have leaks it will leak a like amount regardless of synthetic or regular type oil.
I agree that 15/40 is fine, but I would run something thinner for a variety of reasons including start-up flow and fuel economy.
I agree that 15/40 is fine, but I would run something thinner for a variety of reasons including start-up flow and fuel economy.
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Team Owner
Joined: Jul 2004
Posts: 28,521
Likes: 3,312
From: Hartford WI
Pro
Joined: Nov 2011
Posts: 542
Likes: 2
From: Miami FL
I have used both for the longest time and in two particular cars that I bought uses but low mileage and changed to synthetic oil, both developed slow leaks right after the oil changes that were nbot present before. This is my actual experience, not hearsay. I did solve the leaks and all was good after that.
Last edited by speedycat3; Mar 18, 2013 at 03:48 AM.
Race Director
Joined: Aug 2000
Posts: 11,470
Likes: 765
Last edited by Joe C; Mar 18, 2013 at 04:15 AM.
Le Mans Master
Joined: Jul 2004
Posts: 6,234
Likes: 699
From: Clifton Park, NY ............Clearwater, FL ... 85 Original Owner
Pro
Joined: Mar 2013
Posts: 700
Likes: 162
From: Huntington WV
All BS aside, to answer the simple question..YES, it is ok to run Royal Purple brand but stick to the correct viscosity for the car. Is it necessary or will it help performance? Not so you would actually notice it.
Team Owner
Joined: Jul 2004
Posts: 28,521
Likes: 3,312
From: Hartford WI
urban legend! show me one lab report analysis, done by an independent laboratory, or manufacturer, that's shows a transmission failure caused by a full fluid flush. BET YA CAN'T... if any of that crap were true, it would be plastered all over the FSM's. i'm not saying that there hasn't been a failure after a flush, but i'd bet those transmissions had issues before the flush, and in desperation the owner (or shop) tried a full service as a last resort. shortly after, the transmission fails - blame the flush. ...and the legend begins.
What it probably came from is someone who flushed his trans as it was on it's last legs in the hopes that it will miracle itself into healing and it didn't.
Team Owner
Joined: Jul 2004
Posts: 28,521
Likes: 3,312
From: Hartford WI
I have done it with high and low mileage cars and so far, we have not found a single leak that could be attributed to the oil. Just because it is unexplained doesn't mean the first answer that comes to mind is the right one.
Le Mans Master
Joined: Jul 2004
Posts: 6,234
Likes: 699
From: Clifton Park, NY ............Clearwater, FL ... 85 Original Owner
Use Mobil 1 since new, develop leaks over the next 20 + years. Leaks stop after switching to regular 5-30 oil. Was suggested to try it from the local vette shop. Nothing else was done.
It worked
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
^There it is then^ Scientific PROOF! 
There are many reasons why it MAY have stopped leaking, if in fact it stopped leaking, slowed or whatever. I have more than your one anecdotal example, but going the other way, that "proves" that synthetic oil doesn't cause leaks -as I have swapped every car I've owned TO, synthetic after buying it. These would all (but two of them) be considered "high mile". I would guess that the additive package in your conventional oil had something to help older seals...but don't know.
It's cool for you however, that you fixed you oil leaks w/an oil change.
There are many reasons why it MAY have stopped leaking, if in fact it stopped leaking, slowed or whatever. I have more than your one anecdotal example, but going the other way, that "proves" that synthetic oil doesn't cause leaks -as I have swapped every car I've owned TO, synthetic after buying it. These would all (but two of them) be considered "high mile". I would guess that the additive package in your conventional oil had something to help older seals...but don't know.
It's cool for you however, that you fixed you oil leaks w/an oil change.
Last edited by Tom400CFI; Mar 18, 2013 at 10:51 AM.
Drifting
Joined: Nov 2012
Posts: 1,331
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Burning Brakes
Joined: Jul 2012
Posts: 826
Likes: 3
From: Seabeck WA
Besides synthetics, which I don't think you want to switch to at this stage of the game, UNOCAL's Royal Triton Purple is probably the finest motor oil you can buy. Problem: It's not being made anymore, so buy it up whenever you can find it!
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