Eyal 951

I feel the same about mobil. Aside from the performance weights (15w50) It doesnt even meet standards it should anymore! Mobil one is an efficiency gas milleage oil now.
Castrol Syntech (German Castrol) Is apearently an oil that doesnt burn and thin at the track, meets all the standards, and is relativly easy to get. Thats What I will be using. My oil pan gasket a did a year and a half ago is seeping. I think my RMS is as well. I wonder if switching oils will fix it for a while.
Eyal

pk951

Smokey Yunick says if i went racing today. I'd use Mobil-1 15w50.

ehall

This is a more important staement, in the context of an oil discussion than people would think, regardless of how obtuse.
*sorry peckster

The reality is that the VAST majority of these cars are road cars with a lot of time on the clock. Some, like peckster, and ski, have had the time, ooportunuity, and money to get everything in tip top shape, so they don't have to fight with small leaks. However, most of us are in the process of getting our cars into the state, which as noted above, takes time, opportunity and money. That means living with conditions while slowly, but continually fixing the leaks etc. Ofcourse there are ALL of the other little things that come up along the way, that also need attention.
So my point is that there are, say a hand full of oils, that are top notch, and show less propensity to leak, while there are others, like mobil 1 **** water, that pour through an engine like it is a sieve. Not all brands do that, even in the same weights.
In a perfect world get your leaks fixed. In the real world this info is important.
I can't help feeling that an oil that is so willing to find ANY orifice from which to leak, isn't doing crap all to coat the moving parts of my engine when it's cold. (That's is pure speculation on my part) I used mobil 1 for about two years, and never liked it, with 3k oil changes. The Valvoline that I'm running has totally stopped the leaking on the exact same engine. I'm going to try AGIP to see if I get the same of similar results, if not, I'll try Royal Purple. If neither does as well, I'll be back to valvoline in a heart beat.
My point is that reality for some, in terms of engine conditions, is very different for others. You have to do what's best for your engine, rather than drinking the poison cool-aid of some Amsoil distributer, or the opinions of a bunch of people whose cars are all in varying states of upkeep.

streckfu's

With regular oil changes of ~3k miles, it doesn't matter what you use; especially on a street car (dino or synthetic of the same weight). I can understand synthetic on a track car but you are wasting money otherwise. Dino oil is fine if you change your oil at regular intervals.

That being said, I've used Castrol GTX 20w50 in the summer and 10w30 in the winter.

Zero10

Oh no... this is the same as asking 'What religion is best?'

The general consensus in my mind is this:
Stay with synthetics. They are proven to be far superior in their lubricative ability, and longevity. You can go with longer oil change intervals, and maintain better protection than with conventional oils.

When picking a synthetic oil, my favorite brands (in this order) are:
Amsoil, Royal Purple, Mobil 1, Elf, Motul, Castrol
Then most of the other synthetics rank about the same on my list, including all house brands.

Unfortunately everybody is going to have a different view on this.

chris951

I used Valvoline in my car when I bought it and NO leaks, then I started using Mobil 1 15w-50 and leaks started appearing everywhere. I switched to Castrol 20w-50 and doesn't leak as much, however, the Mobil did its damage to my oil pan gasket(I'll be doing that spring break).

Mobil 1 is sooo thin even at 15w-50 and lets remember on an older engine is not a good idea. I'm not exactly sure the 951 oil system was designed for oil as thin as Mobil 1. I've heard great things about Amsoil, Royal Purple, and Red Line, but for costs sake, Castrol and Valvoline are good alternatives to expensive synthetics unless you are going to seriously track your car. Castrol, Valvoline and synthetics do not sludge up like Quaker State.

My experience working part-time as a mechanic is Quaker State is the WORST thing you can run in your engine. I've seen countless engines not make it to 100k miles because of Quaker State. It sludges up into carbon and sometimes becomes sticky like nasty earwax and pepsi mixed.

reno808

Dam i have been running 20/50 quakerstate hp oil for the last past year. i hope i didnt damage anything.

lleroyb

"Oh no... this is the same as asking 'What religion is best?'"

I am beginning to think there is some truth to this Zero10. Yesterday I decided to go the boutique oil route and bought a case of Redline 20w-50 at a local autoparts store. I frequent the place already for most of my non-Porsche needs so I won't have too much trouble buying it.

According to the owner's manual 20w should be good for as low as I will likely see here in Seattle(- 10 deg. C or 14 deg. F). Frankly the goofy bottles were a PITA, there is a foil paper seal instead of a cap seal. I had to push it in then pry it out with a knife to make sure the seal did not end up in the car. The case of 12 was $100 with tax I hope it is worth it. So far I have only driven it off of the ramps. Wish me luck.

Lou

Zero10

I forgot Redline in my list. It goes about in the middle. I have it in the gearbox on my 951, and I'm not impressed with it, but they show some pretty promising test results, so they still make it on my list.

Sure there is some truth to all of this, synthetics > covnentionals, and I built my list from as many independant tests that I could find, so hopefully it's pretty close. But, notice how there are still some people saying that a conventional will protect as well as a synthetic, and that Mobil 1 destroyed oil pan gaskets?....

pk951

Mineral oil will not protect the same as full synthetics thats total bull-****. Synthetics can take more heat than mineral oil period even when all the additives are broken down.

TurboTommy

Who says that just because the oil is thinner it doesn't lubricate as well!
High quality synthetics have high shear strength (even though they're thinner) and yet have less drag on moving parts (less heat). The oil gets into every nook and cranny of the microscopic imperfections of the parts. Oil pressure might be less because it flows easier; no big deal.

If it causes leaks in your older sludged up (artificial sealant) engine, that's not the oil's fault.
If there's more in your catch can, because of a less than perfect tight engine, that's not the oil's fault.

Unless you've attended share holder meetings at exxon/Mobil, how the f@#k would anybody know if they changed the formula of their products; nobody can just make statement like that!

For what it's worth, I've witnessed professional race teams using mobil 15w 50, like in bottles and cases you'd get from Wallmart.

danny951

I think the point tommy is that people have been noticing a difference in the Mobil 1 formula. I've ready a lot of posts where people have noticed a difference over the last year or so. No one can say for sure, but they have made those observations.

Ski

[QUOTE=TurboTommy]

Unless you've attended share holder meetings at exxon/Mobil, how the f@#k would anybody know if they changed the formula of their products; nobody can just make statement like that!

QUOTE]

Like share holders give a rats A$$. I stand by the statement becuase it was done a new engine(complete) that has 140+ compression, less than 2% leakdown and it stopped when the oil was changed - and it is my opinion and many others as well about it leaking more. I work in the oil industry, I have friends at Exxon in Houston, I'm not using it anymore.

RKD in OKC

When I had my 88 Turbo S I languished over oil and found after talking to several oil reps that the main thing that breaks down oil is water. Yes heat was partially a factor, but the main reason for changing oil at regular intervals was not the breakdown of the oil due to heat, but water. In that car I ran 15w40 Pennzoil Long Life and changed the oil religiously at 3000 miles. It ran great, didn't leak, and was much much cheaper than synthetics even at twice the oil change interval.

In my current 89 Turbo I have tried several brands of synthetics (mostly because that is what the previous owner was running). And have had all kinds of leaks to track down, and I noticed that the stuff turns to water after a hot day at an autocross event. So much so that the idle oil pressure drops to below two and I get a flashing !

Really leaning towards giving the old Longlife 15w40 a try once again.

lleroyb

Tommy Turbo: "For what it's worth, I've witnessed professional race teams using mobil 15w 50, like in bottles and cases you'd get from Wallmart."

Me too, that is one of the things that torments me the most. On the other hand, advertising is advertising. The ALMS teams (AJR) for example put several loose quarts of Mobil-1 on their carts that go to the pit row, in plain sight. Funny thing is I have never seen them check the oil until the car gets back to the paddock. They must be putting the oil on the cart for show, or so it would seem.

As far as Mobil-1 changing, if you look at my other recent post and check out the two sites it would appear Mobil-1 had better numbers in 1991 than it does today. The viscosity index, flash point and pour point are all lower.

Yesterday I drove the car with the Redline in it and got the highest oil pressure I have seen yet. The needle aligned exactly with the 5 bar mark. With 15w 50 M-1 it would be on the lower edge of the 5 mark after an oil change. Warm idle pressure was a little higher too.

Lou