Oil

hoover · 05-01-2004, 01:35 PM

What do you guys think please, I want to use Mobil 1 15/50 but most stores sell 0/40, I'm thinking the latter might be too thin on an 84000 miler.

..P · 05-01-2004, 04:19 PM

Im running Mobil-1 15w50 in two 944s, a 928 and twin Ford 427 solid lifter marine motors, and they all love it.

The oldest 944 is a '84 with 160,000 miles, and the '90 has 88,000.

I interviewed several oil engineers, Mobil being one, for a publication a while back, and the Mobil guy said he would use the 15W50 on a 928 all year long, even if he lived in Cleveland Ohio. Come to find out, it will flow down to colder temps than some 5 weight dinosaur oils will. I like the fact that it will flow so well when cold, thereby keeping the most dangerous wear situation to a minimum, and still be able to function well when hot. A real hot 50 weight oil is about the same as a cold 30 weight, in some senses (film strength) but even when cold this stuff flows incredibly well.

It also burns with "no ash". The '84 sometimes smokes a bit upon startup "IF" it sits for a week, because this oil seeps into places other oil can't go as easily, down valve stems. If I run the car every day I get none of this, but if it sits a week, I'll get a bit of blue smoke. A 0-40 doesn't sound like a good choice to me, but that my opinion.

As for gear lube, look up the Amsoil page, and look at the Series 2000 75-90, I can tell you this is the greatest stuff since sliced bread for a 944 transaxle.

regards, P

hoover · 05-02-2004, 06:41 AM

Thanx for you detailed reply, I'll hang on for 15/50, sounds to be the best bet.

CJFusco · CJFusco's Garage

in a recent magazine article - it was either EXCELLENCE or 911 & PORSCHE WORLD - it was recommended that ANYONE with an older 944 or 928 should run 15W-50 oil all-year round, preferrably synthetic. The only drawback to this is that synthetic oil seems to find a way to leak where conventional oil wouldn't - according to the article, if there is a small hole/crack somewhere, residue from the conventional oil would cake up (like a scab) and the leak would be less prominent. This doesn't happen with synthetic oil, causing it to leak a bit more.

mambodave · 05-02-2004, 07:04 AM

I use Moble 1 15/50 also.

You said you cant find it?

Walmart, Napa, Advance,Autozone,Pepboys carry it

Belive it or not, Walmart seems to always have it.

hoover · 05-02-2004, 10:36 AM

Well I've found a supplier, and the oil is now in the engine, pity about the price, had to buy two 4litre cans. The filter removal was a bit messy. Thanks for the input.

Zero10 · 05-02-2004, 10:38 AM

I'm running Amsoil 20W50 in my tired ol 944. It really likes it, brought the compression up almost 40psi (from 100 to 138ish). Drives better, better mileage as well, but mine's a real extreme case.

I'll vouch for the series 2000 75W90 gear oil. Made my transmission feel like it was brand new (Seriously!). Plus, it's freakin green!

mambodave · 05-02-2004, 11:05 AM

Quote:

Originally posted by Zero10
I'm running Amsoil 20W50 in my tired ol 944. It really likes it, brought the compression up almost 40psi (from 100 to 138ish). Drives better, better mileage as well, but mine's a real extreme case.

I'll vouch for the series 2000 75W90 gear oil. Made my transmission feel like it was brand new (Seriously!). Plus, it's freakin green!

Synthetic? Where do you get it?

..P · 05-02-2004, 06:02 PM

Good to hear the supporting info for the Mobil 1. I contend it's about as close to a "no wear" situation you can get. Of course, having said that, I do contend Amsoil is a better product, but not sure just how much better due to cost, but yes, Amsoil is a fine motor oil.

As for the gear lube, the reason I recommend it, is because it made such a great difference in my transaxle with 165,000 miles on it.

You have to go to the Amsoil web site to get a line on how to order the stuff, and the'll ship to any address. It's a bit pricey, but the gear lube sure beats a trans rebuild.

P

hoover · 05-03-2004, 12:46 PM

This Amsoil seems great stuff, but I'm hearing stories of synthetic not too good for brass/bronze bearings in g/box. Others say no problem. Anyone got the true facts?

..P · 05:48 PM

Quote:

Originally posted by hoover
This Amsoil seems great stuff, but I'm hearing stories of synthetic not too good for brass/bronze bearings in g/box. Others say no problem. Anyone got the true facts?

Yes indeed, I have the answer for sure.

First of all, it's the GL rating that has to do with "yellow metals" in the gearbox. Normal "dino" gear lubes get much hotter than synthetic, and therefore they must take care to keep the sulphur in the oil from reacting with the yellow metal and causing corrosion. This was apparently done with special blends and additives.

Synthetic gear lube runs so much cooler that this is generally not a problem in the first place.

You will note, Amsoil Series 2000 75W90 has a "GL" rating that includes the Porsche requirement, and exceeds the Porsche requirement. You will also note, if you look far enough into the Mobil-1 gear lube, that it does not meet the Porsche requirement, however, since it is a cool running synthetic it is "probably" ok to use, but Amsoil clearly has the advantage with their gear lube. I have not compared Amsoil to Red Line, which I understand has a good product but the Series 2000 is one heck of a good product, and you have absolutely NO WORRY about anything in a Porsche transaxle if you're using that product. I was amazed at the difference it made in my high milage 1984 944, made it quiet and also shift much better.

Check this link for Amsoil. You will see it's rated from GL2 through GL5. Compare any other gear lube to this spec, if it's better, it must be one heck of a fantastic product. http://www.amsoil.com/products/tgr.html

If you take this advice, then you may also want to take the advice I offer about K&N air filters, which apparently only on this forum, seem to have some fans. They're junk, offer no improvement in milage or power, and admit way too much microscopic silica, thereby accelerating the wear between rings and cylinder walls. If you don't take the advice on K&N, then you may not want to take the advice I offer on the gear lube either, because I may not have a clue about what I'm talking about. lol

regards, P

serge944 · serge944's Garage

Quote:

Originally posted by mambodave
I use Moble 1 15/50 also.

You said you cant find it?

Walmart, Napa, Advance,Autozone,Pepboys carry it

Belive it or not, Walmart seems to always have it.

Ya, i always get it at wal mart. Usually cheaper than anywhere else...3.89 a quart.

nickd · 05-04-2004, 09:11 AM

There has been some talk lately about Mobil 1 not "adhering" (for lack of a better description) to engine components as well as dino oil. For example, if the oil pickup gets briefly uncovered in a high-g turn then the dino oil seems to stick to the engine components a little longer than the synths until the oil pickup can pull some more oil through the system. Thus giving you a little more protection in such a situation. This is just through the grapevine.

I use Mobil 1, but it's in a brand new turbo engine which definately benefits from the synth properties. If you're tracking the car you might want to check out this "adhering" property amongst other brands. Maybe some of the fancier brands like Royal Purple, etc. do a better job than Mobil under these conditions.

As far as the Amsoil synth gear oil- I would NOT recommend a one size fits all GL rating. I don't care who makes it. Each GL rating has very specific properties and a GL5 is not necessarily better than a GL4 (actually worse in many situations). The 944 Audi trans use GL4. My G31 Porsche 'box uses a GL5. Each oil is suited to the two the boxes.

That being said, Mobil 1 only offers a GL5 and no GL4 gear oil. So, no, you shouldn't use Mobil 1 in your 944 trans. I feel like Amsoil is the latest snake oil. Any manufacture that has a dyno chart claiming an extra 25hp (even if it is a big V8) by switching to their oil is full of it.

-nick

Manute · 05-05-2004, 06:02 AM

I use Catrol GTX 15/50.Nothing but classics.

hoover · 05-05-2004, 12:30 PM

If I change to synthetic, will there be a reaction with what's left of the 'old' oil in the g/box? Will I need to flush it somehow? Thanx.

Zero10 · 05-05-2004, 11:19 PM

I changed the gearbox oil to a cheap GL4 synthetic, and drove it for 3-4 months before putting in the Amsoil, but the old transmission fluid was almost like caramel it was so thick, and it just stank! So I figuried mine needed some extra cleaning. For the most part, you should just drain and fill with the new stuff. I'm sure there is some way to flush it, although it may not be very easy to do.

I also am skeptical of the one-GL-fits-all claim, but I really like the results of their wear tests, and I have seen them backed up elsewhere, so I am inclided to believe them.
The one thing that does worry me, is that the series 2000 gear oil is a LIFETIME oil, as in, never change it. That sounds like a terrible idea to me. Maybe I'll double the drain interval, but surely not lifetime.

I don't know if Amsoil is worth the extra bucks for putting in the engine, but I found it pretty cheap in Calgary, so I decided to chance it. It is staying much cleaner that the Mobil 1 did, but it's also a much thicker oil.

I heard about that adhesion issue before, but the last time I heard of it was about 10 years ago. From what I understand, all the good synthetics adhere to the metals, so even when there is no oil flow, there is still librucation. To help prevent damage on startup. I could be wrong though.

Blackfoot · Blackfoot's Garage

I used to get librucated when younger, but now have gotten away from that.

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