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-   -   Synthetic Oil? (https://www.gmforum.com/performance-brainstorming-tuning-96/synthetic-oil-238793/)

Joeywhat 07-08-2006 12:30 AM

Synthetic Oil?
 
How many people here use synthetic oil? I am going to do a tune up at my next oil change, and, among other things, am planning on switching to a synthetic. how many miles do you guys get before needing to change? I've heard many people say they can manage 5000-7500 miles under normal driving conditions.

I will be using Royal Purple oil, not any of the fake stuff.

willwren 07-08-2006 01:11 AM

Royal Purple is of no added benefit over any other fully synthetic oil, but has added costs. My suggestion would be to save the money, and use a less expensive synthetic with a trusted name.

On the flip side, we have cars here well over the 300k mark, and they've had nothing in them but dinosaur juice.

FattyAzzBonneville 07-08-2006 01:23 AM

my dad bought my car new and since day one he used mobil 1 10w30 synthetic oil every 3000-4000 miles and even at 118k on my car i still get 165 psi in each cylinder. that pretty good compression if u ask me. although my car runs 17's and we cant figure out why :lol:

I have no idea if this is true but my dad allways tells me that if you take a car with 50k that has used regular oil and you put in synthetic it will leak out because the seals are used to the bigger molocules? i doubt this, but is it true?

willwren 07-08-2006 08:55 AM


Originally Posted by FattyAzzBonneville
my dad bought my car new and since day one he used mobil 1 10w30 synthetic oil every 3000-4000 miles and even at 118k on my car i still get 165 psi in each cylinder. that pretty good compression if u ask me. although my car runs 17's and we cant figure out why :lol:

I have no idea if this is true but my dad allways tells me that if you take a car with 50k that has used regular oil and you put in synthetic it will leak out because the seals are used to the bigger molocules? i doubt this, but is it true?

Fatty, my SSEi had Dino Juice in it for it's first 85k miles, and I switched to Mobil1. I have yet to personally see any of these rumored 'leaky' cars after switching. It's an automotive myth and if there's any truth to it, they are very isolated cases.

I switched my SLE ove at 115k, and haven't seen a drop of oil leaked or used either.

toastedoats 07-08-2006 09:24 AM


Originally Posted by willwren

Originally Posted by FattyAzzBonneville
my dad bought my car new and since day one he used mobil 1 10w30 synthetic oil every 3000-4000 miles and even at 118k on my car i still get 165 psi in each cylinder. that pretty good compression if u ask me. although my car runs 17's and we cant figure out why :lol:

I have no idea if this is true but my dad allways tells me that if you take a car with 50k that has used regular oil and you put in synthetic it will leak out because the seals are used to the bigger molocules? i doubt this, but is it true?

Fatty, my SSEi had Dino Juice in it for it's first 85k miles, and I switched to Mobil1. I have yet to personally see any of these rumored 'leaky' cars after switching. It's an automotive myth and if there's any truth to it, they are very isolated cases.

I switched my SLE ove at 115k, and haven't seen a drop of oil leaked or used either.

the only instances of this phantom leaking when switching to synthetic that i am familiar with are when switching to a much thinner oil. like some of these crazy people thinking that 15w40 is benefitial, then switching to 5w30 synthetic.

Switching to synthetic after using petroleum causeing leakage is one of those overly used mechanic myths.

mkaake 07-08-2006 11:03 AM


Originally Posted by willwren

Originally Posted by FattyAzzBonneville
my dad bought my car new and since day one he used mobil 1 10w30 synthetic oil every 3000-4000 miles and even at 118k on my car i still get 165 psi in each cylinder. that pretty good compression if u ask me. although my car runs 17's and we cant figure out why :lol:

I have no idea if this is true but my dad allways tells me that if you take a car with 50k that has used regular oil and you put in synthetic it will leak out because the seals are used to the bigger molocules? i doubt this, but is it true?

Fatty, my SSEi had Dino Juice in it for it's first 85k miles, and I switched to Mobil1. I have yet to personally see any of these rumored 'leaky' cars after switching. It's an automotive myth and if there's any truth to it, they are very isolated cases.

I switched my SLE ove at 115k, and haven't seen a drop of oil leaked or used either.

:stupid:

People had me pretty well afraid to try synth, but I went ahead and did it anyway, well after the 100k mark. If I searched, I could probably find just how many miles I *did* have, but memory strikes me as being around 115k. I'm a lot further along in miles now, and it doesn't leak a bit more than the dino juice did.

On the other hand, I now have consistent oil pressure. Cold start? No problem. 55 psi. Hot start? No problem. 55 psi. Cruising? No problem. 55 psi. Always constant, no matter what I do to it.

As for oil life, I let my car tell me when to change the oil. Twice, to compensate for running synth. I've never had any issues doing this at all, but there are others who would rather stick to a specified mile interval...

MACDRIVE 07-08-2006 03:14 PM

I've been using Valvoline MaxLife 10W-40 in my L36. Very impressed! The MaxLife is a thin 10W-40 and part synthetic. My oil pressure has gone from 45psi hot to 55psi hot. Fuel mileage is up by 5mpg. Engine feels smoother (less buzz) at all rpms.

If I was to go full synthetic, I would try the Valvoline Synpower 5W-40. :D

TommyGloves 07-08-2006 04:17 PM

I use Mobil 1 (5 qt jugs from Walmart) in both my SSEi and GTP (Wife's Aztek as well). I use to change it every 3K, but noticed that I could go for as long until the Oil Change Indicator pops on.

Joeywhat 07-08-2006 04:58 PM

I will probably stick to royal purple because 1) I use it in my camaro, and I know how well it works, and 2) I already have some, so I won't have to buy anymore as of now. I may look into some of the cheaper stuff after the next oil change. I have also heard good things about AMSOIL synth oil, so I may try that afterwards.

So it sounds like there is some noticable improvement in mileage with the synth oil? I'm not terribly interested in getting better mileage (although it is nice), I just want to keep my car running well, and hopefully save a few bucks by changing my oil every 5000 miles or even longer.

Timothy's Buick 07-09-2006 12:06 AM


Originally Posted by willwren

Originally Posted by FattyAzzBonneville
my dad bought my car new and since day one he used mobil 1 10w30 synthetic oil every 3000-4000 miles and even at 118k on my car i still get 165 psi in each cylinder. that pretty good compression if u ask me. although my car runs 17's and we cant figure out why :lol:

I have no idea if this is true but my dad allways tells me that if you take a car with 50k that has used regular oil and you put in synthetic it will leak out because the seals are used to the bigger molocules? i doubt this, but is it true?

Fatty, my SSEi had Dino Juice in it for it's first 85k miles, and I switched to Mobil1. I have yet to personally see any of these rumored 'leaky' cars after switching. It's an automotive myth and if there's any truth to it, they are very isolated cases.

I switched my SLE ove at 115k, and haven't seen a drop of oil leaked or used either.


I think this myth originated from older cars, which would leak oil right from the factory, putting synthetic, older synthetic would just worsen the leaks. I know, in my Citation, with 307060 kms, it leaked oil everywheres, putting synthetic would make it horribly worse.

I was afraid that switching to synthetic would break down seals in my 3800, but it never leaked to begin with and besides, if the oilpan seal leaks, i can easily remove it and reinstall it in 1/2 hour, lol.

I run Mobil one, 10w30 super synthetic. I grab a jug when its on sale, and my goodness, its delicious stuff!! :lol:


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