Another Oil Thread - Synthetic vs Mineral
01-18-2012, 12:34 PM
#1
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Another Oil Thread - Synthetic vs Mineral
I've read a lot of the previous threads on oil but wanted to nail down a consensus of synthetic oil vs. mineral oil. Years ago I was told the the synthetic oil on the market did not have the same sealing characteristics of mineral (regular) oil and thus could leak past rings and cause other seals to leak. Some more recent pundits state that the synthetic oil on the market has done away with that problem. Any opinion?
I am looking to track my 1987 951 this season and want to use synthetic for obvious reasons but want to make sure it is the right choice. Any opinions either way and on weight as well?
Thanks to all the RLers!
I am looking to track my 1987 951 this season and want to use synthetic for obvious reasons but want to make sure it is the right choice. Any opinions either way and on weight as well?
Thanks to all the RLers!
01-18-2012, 12:53 PM
#3
Rainman
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I stick with dinosaur blood for the reason that Synthetics were not quite so available in the 1970s when our main bearings were designed. Everything in the 944 engine is a product of 1976-1982 engineering and design philosophy. Seals are intended for use with dinosaur juice, rings and bearings designed around it as well. My grandfather spent his life working in the petroleum industry and was one of the players involved in developing modern weight mineral oils and synthetics, and I trust his advice here.
While it may be true that modern synthetics have been developed to the point that they can keep the seals hydrated and rings sealed, the cost difference alone is enough to keep me on mineral oils, although that price gap is starting to close.
I rebuilt my engine in 2005/early 2006 and have run exclusively 20W-50 dinosaur oil in it, mostly Pennzoil, changed every 3 months with the filter since then. Early last year I had the oil pan off (had the engine out of the car, figured I may as well replace the pan gasket for good measure) and there were no signs of sludge and barely a light coat of "varnish" after 5 years. See picture.
Just put 6.5 quarts of 20W-50 in on Saturday and it's running strong
While it may be true that modern synthetics have been developed to the point that they can keep the seals hydrated and rings sealed, the cost difference alone is enough to keep me on mineral oils, although that price gap is starting to close.
I rebuilt my engine in 2005/early 2006 and have run exclusively 20W-50 dinosaur oil in it, mostly Pennzoil, changed every 3 months with the filter since then. Early last year I had the oil pan off (had the engine out of the car, figured I may as well replace the pan gasket for good measure) and there were no signs of sludge and barely a light coat of "varnish" after 5 years. See picture.
Just put 6.5 quarts of 20W-50 in on Saturday and it's running strong
01-18-2012, 01:17 PM
#5
I stick with dinosaur blood for the reason that Synthetics were not quite so available in the 1970s when our main bearings were designed. Everything in the 944 engine is a product of 1976-1982 engineering and design philosophy. Seals are intended for use with dinosaur juice, rings and bearings designed around it as well. My grandfather spent his life working in the petroleum industry and was one of the players involved in developing modern weight mineral oils and synthetics, and I trust his advice here.
While it may be true that modern synthetics have been developed to the point that they can keep the seals hydrated and rings sealed, the cost difference alone is enough to keep me on mineral oils, although that price gap is starting to close.
I rebuilt my engine in 2005/early 2006 and have run exclusively 20W-50 dinosaur oil in it, mostly Pennzoil, changed every 3 months with the filter since then. Early last year I had the oil pan off (had the engine out of the car, figured I may as well replace the pan gasket for good measure) and there were no signs of sludge and barely a light coat of "varnish" after 5 years. See picture.
Just put 6.5 quarts of 20W-50 in on Saturday and it's running strong
While it may be true that modern synthetics have been developed to the point that they can keep the seals hydrated and rings sealed, the cost difference alone is enough to keep me on mineral oils, although that price gap is starting to close.
I rebuilt my engine in 2005/early 2006 and have run exclusively 20W-50 dinosaur oil in it, mostly Pennzoil, changed every 3 months with the filter since then. Early last year I had the oil pan off (had the engine out of the car, figured I may as well replace the pan gasket for good measure) and there were no signs of sludge and barely a light coat of "varnish" after 5 years. See picture.
Just put 6.5 quarts of 20W-50 in on Saturday and it's running strong
01-18-2012, 01:30 PM
#6
Instructor
I had a Q45 that leaked like a seive when I used full synthetic...but didnt leak a drop on dyno oil. I suggest blend as a minimum or pure dyno to keep seals lubricated.
I understood new cars changed their seals, not that the new synthetics were good for older engines...anyone know the definitive answer?
I understood new cars changed their seals, not that the new synthetics were good for older engines...anyone know the definitive answer?
01-18-2012, 02:53 PM
#7
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I stick with dinosaur blood for the reason that Synthetics were not quite so available in the 1970s when our main bearings were designed. Everything in the 944 engine is a product of 1976-1982 engineering and design philosophy. Seals are intended for use with dinosaur juice, rings and bearings designed around it as well. My grandfather spent his life working in the petroleum industry and was one of the players involved in developing modern weight mineral oils and synthetics, and I trust his advice here.
While it may be true that modern synthetics have been developed to the point that they can keep the seals hydrated and rings sealed, the cost difference alone is enough to keep me on mineral oils, although that price gap is starting to close.
I rebuilt my engine in 2005/early 2006 and have run exclusively 20W-50 dinosaur oil in it, mostly Pennzoil, changed every 3 months with the filter since then. Early last year I had the oil pan off (had the engine out of the car, figured I may as well replace the pan gasket for good measure) and there were no signs of sludge and barely a light coat of "varnish" after 5 years. See picture.
Just put 6.5 quarts of 20W-50 in on Saturday and it's running strong
While it may be true that modern synthetics have been developed to the point that they can keep the seals hydrated and rings sealed, the cost difference alone is enough to keep me on mineral oils, although that price gap is starting to close.
I rebuilt my engine in 2005/early 2006 and have run exclusively 20W-50 dinosaur oil in it, mostly Pennzoil, changed every 3 months with the filter since then. Early last year I had the oil pan off (had the engine out of the car, figured I may as well replace the pan gasket for good measure) and there were no signs of sludge and barely a light coat of "varnish" after 5 years. See picture.
Just put 6.5 quarts of 20W-50 in on Saturday and it's running strong
Any thoughts to the blend some have suggested? The higher temperatures of a track day concern me. I am thinking about installing a Lindsey oil cooler.
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01-18-2012, 04:36 PM
#8
I've read a lot of the previous threads on oil but wanted to nail down a consensus of synthetic oil vs. mineral oil. Years ago I was told the the synthetic oil on the market did not have the same sealing characteristics of mineral (regular) oil and thus could leak past rings and cause other seals to leak. Some more recent pundits state that the synthetic oil on the market has done away with that problem. Any opinion?
A widely accepted concensus on leakage when switching is based on detergent content. The idea being that deposits of dirt or sludge actually clog or seal the small imperfections in the seals. Synthetics with their detergent blends clean these small imperfections either creating leaks, or worsening them.
Most studies I've read concluded that their is no real advantage to a synthetic oil over a mineral oil under normal driving conditions. The synthetics do have a better tolerence to high oil temperatures, low temperature flow, and also better sheer stability (oil film/hydrodynamic wedge).
As far as the bearings, rings, and seals being designed to use mineral oil...I highly doubt that to be the case, but maybe an engineer can chime in, as I am just self educated on topics such as these. I pulled my old engine apart with 181,000 miles (45,000 of which were from me with synthetic oil, and new front engine seals) and the crank main and rod bearings looked great, with minimal varnish and no discernable sludge.
I am also running full synthetic in my new engine on the advice from the builder.
01-18-2012, 04:52 PM
#9
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This thread will resolve nothing!!! 
On a turbo, I'd be inclined to run synthetic due to possible higher underhood temps and wanting to keep the turbo lubricated safely. On an N/A car, Dino would be fine since underhood temps are usually lower.
With any oil, the regularity of changing and getting it tested might be of more value than the Synthetic vs dino debate.
Go ahead and track your car with a "proper viscosity" oil as spelled out in the owner manual. I too am of the old school of adding a "bit more" than dipstick full to try and keep the oil pick up points able to do their job.
On a turbo, I'd be inclined to run synthetic due to possible higher underhood temps and wanting to keep the turbo lubricated safely. On an N/A car, Dino would be fine since underhood temps are usually lower.
With any oil, the regularity of changing and getting it tested might be of more value than the Synthetic vs dino debate.
Go ahead and track your car with a "proper viscosity" oil as spelled out in the owner manual. I too am of the old school of adding a "bit more" than dipstick full to try and keep the oil pick up points able to do their job.
01-18-2012, 04:59 PM
#10
Adequate cooling is also a must! The stock system is barely adequate. I installed a larger oil cooler, and on a hot day after a few hard runs I have yet to see anything higher than 200 deg F. I am anxious to see how they will hold up on the track.
01-18-2012, 05:09 PM
#11
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It's better than hanging out on the "I'd hit it" thread and losing hours of my afternoon!
In all seriousness, good information all around. I think I need to invest in a better oil cooler and perhaps I will do a blend of synthetic and dino and get the best of both worlds.
Anyone want to give any advice on oil weight for a track day versus daily driving?
In all seriousness, good information all around. I think I need to invest in a better oil cooler and perhaps I will do a blend of synthetic and dino and get the best of both worlds.
Anyone want to give any advice on oil weight for a track day versus daily driving?
01-18-2012, 07:47 PM
#12
Former Vendor
The one thing that leans me towards synthetic is the longer range you get out of it. If you can get 5 thousand good miles out of synthetic vs. 3 on dino you are money ahead in the long run, no? Synthetic won't varnish on the bottom half, either.
I have ran myself ragged on bobistheoilguy researching this, and it's still clear as mud. BTW, I had my synthetic tested on our XC-90 last time it came out because I just had to know. They said I would have been good to 6800 miles on it. So, I figure good synth. every 6k from now on and quit worrying about it.
I have ran myself ragged on bobistheoilguy researching this, and it's still clear as mud. BTW, I had my synthetic tested on our XC-90 last time it came out because I just had to know. They said I would have been good to 6800 miles on it. So, I figure good synth. every 6k from now on and quit worrying about it.
01-18-2012, 07:55 PM
#13
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You owe it to yourself to check out Brad Penn oil.
http://www.penngrade1.com/
It's expensive, but you get what you pay for.
http://www.penngrade1.com/
It's expensive, but you get what you pay for.
01-18-2012, 08:13 PM
#15
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Look at it this way. How much did you pay to fill the gas tank and how often do you do that? If you treat oil the same way you won't have a problem. Before you track it change the oil, when your done at the track change the oil.