Boeing 717

Had my oil changed today by an Ex Porsche Mechanic, he put this in and said it was good stuff, have you guys had any experience with it??

http://rennsportsystems.com/oils/motul-8100-x-cess/

ilko

I've heard good things about it. My new 993 was serviced with that oil and I would have no qualms about putting it in the 997TT.

Kevin

My recommendation for factory approved oil

http://www.mobil.com/USA-English/Lub...il1_5W-50.aspx

Boeing 717

Hey Kevin, thanks. I wanted to put 50 weight in my car to quiet the rattling a little bit. Do you think that would help?? That particular tech was not a fan of 50 weight and said something to the effect that these engines were designed for 40 weight and he didn't have any in stock so I just went with the 40.
Why do you recommend that?

Boeing 717

New 993??

Macster

The 5w-50 oil is an approved oil.

The problem is people focus on the viscosity. I have to point out that there is more to an oil than its viscosity.

Also, I suspect that "40" or "50" has some variability. Not that the oil viscosity varies from batch to batch but that an approved say xW-40 oil's true viscosity may be a bit higher (or lower, that's always a real possibility too.. everyone thinks "thicker" is better but it may not be) than other non-approved xW-40 oils.

An approved 0w-40, 5w-40, and 5w-50 oil may be quite close in actual viscosity at engine operating temperature compared to non-approved oils.

My point is that the approved 5w-50 may not have that much additional actual viscosity than any of the other approved oils.

But you are welcome to give it a try if you want.

I've run 5w-50 oil in both of my cars and I really didn't notice any decrease in engine noise at any time, other than the normal drop off in engine noise when changing the oil.

Fresh oil in an engine is like getting a new engine in that the engine quiets down some. I notice this even though I change oil every 5K miles.

I'm not a fan of oil additives but techs who I talk to and respect tell me they recommend Swepco 502 oil treatment, the one with micronized Moly. (I had some analyzed: it contains moly -- I forget how many ppm: 200, or was it 2000?; and that's it.)

They tell me they recommend Swepco oil additive (treatment) for engines that do no see regular use, for engines that are used infrequently. The additive reduces engine noise upon engine start. As I've mentioned before I tried some in both engines and didn't really notice any difference even though in one case I added the stuff some few K miles after the oil change. I used it to top up the oil level instead of another bottle of oil.

You have to keep in mind we are talking about IC reciprocating engines that have a lot of stuff going back and forth, up and down, opening and closing, and all happening real close to the cabin. Healthy engines are noisy. Turbo engines are noisier because they are more raw. You are dealing with an engine that from 3.6l produces nearly 500hp. That is some engine and it is not going to idle like a Cadillac engine. It is going to idle more like a race car engine, like a highly tuned engine (which it is) and it is going to be a visceral experience. The Boxster engine idles like a sewing machine compared to how my Turbo's engine sounds at idle. I like it but of course tastes vary.

There is a risk that if one goes too to thick of an oil that the oil may not flow properly when the engine is cold, or when hot it may not flow out of a bearing space taking heat with it. Thus the oil lingers too long and picks up even more heat -- courtesy of its higher viscosity -- and the oil could break down due it its own too high viscosity for the application.

Remember in the case of main/rod bearings the oil is being force into a gap that measures around 0.001 of an inch and is being forced into this tiny gap at up to 60 or more psi. The oil is all that keeps the rapidly rotating main or rod journal from touching the stationary bearing. There is a huge amount of friction involved, hydraulic friction, and pressure, and the oil gets hot. It has to hold together but still flow so it can carry the heat it develops from this friction and pressure and from the metal bearing surfaces in which it is contact with away and the incoming oil that replaces it has a heat level it can tolerate.

Consider what this means: Say the main bearing diameter is 3". The circumference is 9.4". Every revolution has 9.4" of metal going past it. At 6K rpms, that's 100 revolutions per second, so that's 9.4" * 100 or 940" per second of metal going by one stationary spot per second. 940" is 78'. I have seen machine tools with ways/slides that run over 100' in length. To image the amount of heat just the slide (not counting the table weight and the weight of the part on the table) generated if that table could move 78 feet in one second and do this second after second after second is mind boggling.

jhbrennan

I add a bottle of this every oil change and like Macster, I use this to top the oil to the proper level instead of the 9th bottle. Also, like Macster I found it difficult to notice any changes...although it does sound quieter - must be the placebo effect of the additional ZDDP.
http://www.redlineoil.com/product.aspx?pid=121&pcid=1

Kevin

I like the 5W50. In warmer parts of the country the 50 weight does help. I have stack of Blackstone and other oil reports showing that the 40 weight sheer near a 30 weight oil as miles get racked up between oil changes. We want an oil that will be stable and not shear as the miles are put on the engine between oil changes. Porsche states and recommends the 5W50 in warmer climates. This is the very same engine design that ran 15W50. I wouldn't recommend running that weight with the vario cam system.

A wise choice would be to run 5W50 in the summer and 0W40 in the winter. In the Seattle climate I run the 5W40 and 5W50. 20W50 VTwin for my air cooled turbocharged engines.

These engine are like blenders. The multiple vaned oil pumps (four pumps in this engine) chop up the oil at a molecular level. When tested we see this happening. Some oils fair better than others. These are facts with data backing it up. One can also see that as the oil sheers, engine wear increases. The oil samples show more copper, aluminum and iron in these tests.

The better oil is resistant to sheer. Less sheer, equals less engine wear. The idle noise can be reduced and brought to a minimum. As the oil gets mileage on it, the engine at idle will give you that increased noise level.

At the end of the day, pick your oil that you want to run, if you are concerned about noise and oil pressure there are solutions. I would run the 5W50 all year round unless you are in the North with snow on the ground. With the 997TT we can visually see the water temperature AND oil temp. Most of us park our cars in the garage, so in the winter the engine oil doesn't drop to ambient temps.

ilko, I wouldn't recommend running a 5W oil in the air cooled 993 or 993TT. The oil recommendation is the Mobil air cooled VTwin 20W50.

Kevin

Boeing 717, if you look on page 207 in your owners manual it states> above minus 13 F SAE 0W40, 5W40 AND 5W50 is approved by Porsche..

Below -13F OW40 is the only recommended oil.

Dryfly57

It's the only oil I use!

Kevin

As Macster wrote>>

There is a risk that if one goes too to thick of an oil that the oil may not flow properly when the engine is cold, or when hot it may not flow out of a bearing space taking heat with it. Thus the oil lingers too long and picks up even more heat -- courtesy of its higher viscosity -- and the oil could break down due it its own too high viscosity for the application.

This is NOT the case for a 5W50 oil above minus 13F in this engine. There are Rennlisters that are running the BMW Castrol 10W60 for many years. I wouldn't run that weight unless you lived in the desert with temps over 100F. The bearing system that is in our 997TT use the very same main bearings as it air cooled 930, 964 and 993 which used a higher 15W50 and 20W50 spec'd from the factory. The rod bearings that are used in this engine come from the air cooled 993 and 993TT. It is the hydraulic vario cam and multi lift inlet tappets that require the lighter weight oil. It has been reported on Rennlist that folk have noticed less "randon" OIL PUFF's on start up when moving away from OW40..

Boeing 717

Ok thanks for all the info guys. Next round im gonna try the 50 weight.

ilko

Yeah, kinda fell into my lap...

Back on topic, I currently have M1 0W-40 in the 997TT but bought some Mobil 1 5W-40 TDT to try on the next oil change based on some recommendations here...

Igooz

Must be Orange!

ilko

For $14000 it can be.