1990 Corvette Regular vs Synthetic Oil
09-11-2013, 10:12 PM
#1
Advanced
Thread Starter
1990 Corvette Regular vs Synthetic Oil
I believe this car has probably just had regular oil in it its whole life (70k miles). Is there any reason not to switch over to a 5w30 Mobil 1 synthetic for here in the North East? I was all ready to drop 5 quarts in when I read a thread where someone posted that if it has always had regular oil then don't switch, but I can't think of a reason....does anyone know a good reason for me not to go synthetic?
09-11-2013, 10:58 PM
#2
Team Owner
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St. Jude Donor '05
No reason not to go for it.
Wont hurt a thing
Wont hurt a thing
09-12-2013, 07:34 AM
#4
Le Mans Master
In some older cars changing from dino oil to synthetic oil has caused gaskets to leak.... Some people will say this is impossible, but I have had it happen in one of my own vehicles, so it is possible....
...WW
...WW
09-12-2013, 08:43 AM
#5
while synthetic oil most likely won't hurt anything, a late model SBC on dino oil with 3-5K changes will probably outlast you. personally, I don't want my 90 in my funeral procession - 
. i'd be more concerned with the filter quality.
. i'd be more concerned with the filter quality.
09-12-2013, 09:44 AM
#6
Drifting
I would not make a change myself. I run Mobil 1 in my 04 C5, because GM tells me too. I run 10/40 standard in my hybrid L98 just because I always have, and it's my belief that Gen 1's should run a thicker oil. Just my 2 cents!
09-12-2013, 11:19 AM
#7
Make the switch !
There is not a valid reason NOT to do so. Yes, there have been some leaks reported but they could have also been caused by the wind direction that day....or the cloud cover? Pure coincidence. The oils are compatible. I also hear of MANY people claiming that their trans went out when they changed the fluid. That's more likely because they do not change the fluid until the trans is not acting right...again, coincidence.
The benefits of synthetics farrrrrrr outweigh the risk. I run syn in my build L98 and can now go 5000 miles summer and maybe more in winter. Its down to 2 changes per yr. I'll run 5-30wt in a cold climate and 10-40 or 15-50 in extreme heat climates summertime.
As someone elose stated, the choice of filter is even more important. If you use synthetic and because it does not breakdown chemically as fast as conventional oils, you can buy time by just changing the filter after 3-4000 miles. Top off with a qt of fresh syn oil and you're good to go. I actually use the Walmart brand synthetic oil when I'm poor and it seems to have similar properties as the name brands...At $17 for 5 qts....its a deal.
Do some research on filters and make a decision,. That's a personal preference. My advise is to select one that has a good element double layered so it traps more dirt. You will have to change it sooner but that's the point isn't it? to collect and remove the contaminates.
Good luck and enjoy !
There is not a valid reason NOT to do so. Yes, there have been some leaks reported but they could have also been caused by the wind direction that day....or the cloud cover? Pure coincidence. The oils are compatible. I also hear of MANY people claiming that their trans went out when they changed the fluid. That's more likely because they do not change the fluid until the trans is not acting right...again, coincidence.
The benefits of synthetics farrrrrrr outweigh the risk. I run syn in my build L98 and can now go 5000 miles summer and maybe more in winter. Its down to 2 changes per yr. I'll run 5-30wt in a cold climate and 10-40 or 15-50 in extreme heat climates summertime.
As someone elose stated, the choice of filter is even more important. If you use synthetic and because it does not breakdown chemically as fast as conventional oils, you can buy time by just changing the filter after 3-4000 miles. Top off with a qt of fresh syn oil and you're good to go. I actually use the Walmart brand synthetic oil when I'm poor and it seems to have similar properties as the name brands...At $17 for 5 qts....its a deal.
Do some research on filters and make a decision,. That's a personal preference. My advise is to select one that has a good element double layered so it traps more dirt. You will have to change it sooner but that's the point isn't it? to collect and remove the contaminates.
Good luck and enjoy !
09-12-2013, 11:31 AM
#8
Le Mans Master
The synthetic oil is better.
I try to use it in everything even my lawn mowers. It lasts longer without breaking down, better flow in cold weather, same or better lubrication.
As for the synthetic leaking myth or not, If your seals and gaskets are in good shape, the synthetic should be fine. If your seals and gaskets are getting older and borderline, the synthetic will find smaller gaps than dino oil to leak from.
I have switched to synthetic on several cars with no problems, but on my '88 Corvette when I switched at 110k, it started leaking a lot. I had never noticed it leaking with dino oil, but with synthetic it leaked. It was so bad at the valve covers that it would run down and smoke on the exhaust. I replaced the valve cover gaskets and that took care of most of it, but it wasn't done leaking until the next dino oil change.
I try to use it in everything even my lawn mowers. It lasts longer without breaking down, better flow in cold weather, same or better lubrication.
As for the synthetic leaking myth or not, If your seals and gaskets are in good shape, the synthetic should be fine. If your seals and gaskets are getting older and borderline, the synthetic will find smaller gaps than dino oil to leak from.
I have switched to synthetic on several cars with no problems, but on my '88 Corvette when I switched at 110k, it started leaking a lot. I had never noticed it leaking with dino oil, but with synthetic it leaked. It was so bad at the valve covers that it would run down and smoke on the exhaust. I replaced the valve cover gaskets and that took care of most of it, but it wasn't done leaking until the next dino oil change.
09-12-2013, 12:30 PM
#9
Safety Car
As long as you don't have any oil leaks make the change, I have done it on many older cars with great success.
Synthetic oil helps cool the inside of the engine, my 88 used to hold engine oil heat with regular oil, but when I switched the oil temp would drop.
I use it in all my toys and equipment.
Synthetic oil helps cool the inside of the engine, my 88 used to hold engine oil heat with regular oil, but when I switched the oil temp would drop.
I use it in all my toys and equipment.
09-12-2013, 12:57 PM
#10
Le Mans Master
Make the switch !
There is not a valid reason NOT to do so. Yes, there have been some leaks reported but they could have also been caused by the wind direction that day....or the cloud cover? Pure coincidence. The oils are compatible. I also hear of MANY people claiming that their trans went out when they changed the fluid. That's more likely because they do not change the fluid until the trans is not acting right...again, coincidence. !
There is not a valid reason NOT to do so. Yes, there have been some leaks reported but they could have also been caused by the wind direction that day....or the cloud cover? Pure coincidence. The oils are compatible. I also hear of MANY people claiming that their trans went out when they changed the fluid. That's more likely because they do not change the fluid until the trans is not acting right...again, coincidence. !
.The leaks are from the swell rate caused by the different oils.. When you use dino oil you have more gasket swell , then when you change over to synthetic oil on an older car the synthetic causes less gasket swell which lets oil get past the gasket.There are articles all over the web from different oil companys explaining this phenomenon... Rubber gaskets will eliminate this problem...Now the question is will the OP have a problem with his car leaking after switching to synthetic?? Only trying synthetic will answer that question, and if it leaks he can always switch back........WW
Last edited by WW7; 09-12-2013 at 01:44 PM.
09-12-2013, 01:29 PM
#13
Le Mans Master
I just sent you a PM of a post from a site I can't list on here..Read it and believe what the man has to say. He's a well respected person on the subject....WW
Last edited by WW7; 09-12-2013 at 01:46 PM.
09-12-2013, 01:31 PM
#14
Team Owner
One way to know is to do an oil analysis. My Powerstroke is hard on oil so when I took it to 7500 and sent it in, they said to back it down to 5000. We shall see what the 5000 used oil analysis shows
09-12-2013, 03:22 PM
#15
Advanced
Thread Starter
Ok....NAPA Gold it will be....I use Wix Racing on My Grand National. I have always been an AC Delco fan, so I am sorry to have to leave them. Wix makes the Napa Gold filter. Anyone want to buy the 3 AC Delco Filters I just ordered in? lol
09-12-2013, 04:51 PM
#16
Le Mans Master
..Im talking about the store brand Fram filters, not the Pro filters...383Vett schooled me a few years ago on the difference....
..WW
Last edited by WW7; 09-12-2013 at 07:53 PM.
09-12-2013, 05:48 PM
#17
Advanced
Thread Starter
Well I am already a Wix fan. Stock Grand Nationals were always urged to be fitted with the PF52 Delco filter for the slight extra capacity and the anti drainback. This is different I guess. I ordered a set of 56" race ramps 2 days ago and they came today, so I will get it done tonight unless it rains.
09-12-2013, 09:10 PM
#18
Drifting
In some older cars changing from dino oil to synthetic oil has caused gaskets to leak.... Some people will say this is impossible, but I have had it happen in one of my own vehicles, so it is possible.......WW
My 90 leaked a little bit after I first put full synthetic in her, but it has stopped after the second oil change with synthetic.
09-22-2013, 10:28 PM
#20
this winter things are coming apart, and the leaks will be fixed.