My car, an '01 with 34k on the clock, has always run the factory fill, Mobil 1 0w40. However, I also get a puff of smoke every few starts on my car. I have come to the conclusion that the Mobil 1 is breaking down, becoming too thin, and/or slightly losing its viscosity. Perhaps that is why I am getting the puff of smoke as it is leaking past the seals (being so thin and all after it breaks down). I go through 1qt every 1000-1200 miles.

I know that Amsoil has a higher break-down temp and is a true synthetic. I know of a few BMW M owners who would go through about 1qt of Mobil 1 every 1000-1200 miles, but when they switched to the Amsoil, that stopped.

Is anyone running Amsoil 5w40 in their 996TT? If so, what is your experience? I plan on changing my oil this weekend, so any insight as to oil type and weight would be helpful. Remember, I live in Atlanta, so a 0w40 probably isn't needed. It doesn't get cold enough, especially in the spring/summer, to need a '0' lower end. I would like an oil that doesn't break down so quickly.

Ideas?

 

OPC's in Portugal where temperatures don't go below 0ºC (freezing) use Mobil1 5W-40 which is for Porsche only and can only be found through the dealers. What I do is change oil using 5W-40 and I fill up using Mobil1 15W-50 for the extra thickness. Please beware that thicker oil doesn't always mean extra shear capacity for instance a 0W-30 may have a higher resistance to shear than a 0W-40, the reason is that the bigger the difference between the lower and higher number tha more additives it has to keep it stable and these often affect shear capacity negatively.

 

Amsoil 5W-40 is all I run in my car. I'm not a big fan of Mobile-1.

 

Oh really? I just dropped you a PM.

 

Mobil 1 5w40 Truck and SUV, now called Turbodiesel, is another option. I think Amsoil is good, but I wouldn't run it if you're in warranty. There's also no reason not to mix Mobil 1 0w40 and 15w50 if you want it a little thicker.

 

I'm out of warranty. Mobil 1 just seems to break down too quickly with the turbo's temps.
I know that Castrol is Group 3 and that Mobil 1 *was* group 4 at one point, but they might have switched to Group 3 recently when they introduced their "extended life" line. It's hard to get any solid answers, but I can research some more as to a final say for Mobil 1's "synthetic" products.

Group 1 - Conventional - Mineral oil derived from crude oil
Group 2 - Hydroprocessed - Highly refined mineral oil
Group 3 – Severe hydroprocessed - Ultra refined mineral oil
Group 4 – Full synthetics (chemically derived) - Chemically built Polyalphaolefins (PAO).

CASTROL AND MOBIL GO TO BATTLE IN COURT:

Recently, Mobil accused Castrol of reformulating its synthetic by substituting other basestocks in place of its synthetic polyaphaolefins (PAO's). Castrol Syntec is a hydrocracked oil. That's right, Castrol has replaced the PAO synthetic base stock with hydroisomerized "petroleum base stock." Hydrocracking, as it's called, is the highest level of petroleum refining. Castrol isn't even a true synthetic yet Castrol ended up winning the battle when the National Advertising Division of the Council of Better Business Bureaus ruled that Castrol could still market its oil as "synthetic" despite their new formulation. Basically, they expanded the definition of synthetics to include Group III hydroprocessed petroleum oil. This high profile case took place because synthetics are recognized as the market's best hope for growth. Synthetic oil sales have outpaced petroleum oil sales by a wide margin and the gap continues to widen every year. Consumers are getting smarter and demand the best for their vehicles! Read the full story on the Castrol debacle in our informative articles section. Additionally, just as soon as Castrol won this battle, several other major oil companies jumped in and came up with hydroprocessed motor oils of their own and labeled these products to be "100% synthetic", when they still are primarily Group III hydroprocessed petroleum oils!

 

I have been running AMSOIL Series 2000 0W-30 in my MB AMG C36 for the past 10 years and I can say it has been absolutely amazing. I have had people compare Mobile One Synthetic with AMSOIL and there really isn't any comparison. Their website has a TON of information and specs in it. I also use the transmission fluid, differential fluid from AMSOIL and have had just great results. I don't have to change the fluids that often, I have had great gas mileage, and it has just been great. I have not run AMSOIL in my 2001 996 TT yet because I haven't had to change the oil yet...when I do, there are several weights or types of synthetic oils that AMS oil recommends for the TT. You can go to www.amsoil.com and check out what they recommend. I will probably run AMSOIL 5W-40 European Engine Oil, highly recommended for Turbo models and the only oil in North America to be recommended for the latest specifications of all three major European automakers - Volkswagen (Audi), BMW, and MB and also Porsche. Good luck!

 

Divexxtreme,
Just curious, why didn't you run the AMSOIL Series 2000 Racing OW-30 in your TT instead of the European 5W-40? The Series 2000 is the flagship synthetic in the AMSOIL line...did you get better results with the 5W-40?

 

Guys, don't know if I mentioned this before (might have been rennlist) anyway there is a guy based over here who is on most Euro forums called OILMAN, Honestly guys go to a search engine and put "oilman" in and you will find him around, he's in all forums Porsche, Merc, BMW, etc, etc. His knowledge of oil is something else.

www.opieoils.co.uk/lubricants.htm

 

I just had another look at his site and he has a recomend me an oil section where you can fill out info and he will get back to you.

I personally think one of the Admin/Mods should speak to him as it adds another important section to the 6speed site. I will try and find some links where he has given valued advise. He is a diamond geezer!

 

Yip, he has a section on the official Porsche GB site where he gives out advise.

 

Here is a little paragraph taken from Porsche GB

oilman
titleAndStar(237,0,0,false,"","")Non Member



Posts: 237
Joined: 8/7/2004
Status: offline If you would like oil advice or professional recommendations then this is the place to ask.

To help you, you need to help me as I use a proprietory database which requests specific information on the vehicle. Your information is important to allow me to select the correct recommendation.

Please advise the following:

Make
Model
Year
Engine size and type
Modifications
Type of driving (road/track etc)
Current oil used (brand and viscosity)

I will not post prices here (please don't ask) but you can always email me for a list.

I hope this thread will be a useful place in the future as a database for all.

Cheers
Simon

< Message edited by bones -- 18/10/2004 16:27:48 > Report | Post #: 1 RE: Oil advice and recommendations - 15/9/2004 11:57:58 showPicture("9/15/2004 11:57:58 AM",0,0,0,75433,101)oilman
titleAndStar(237,0,0,false,"","")Non Member



Posts: 237
Joined: 8/7/2004
Status: offline Some basics here so it may be worth reading before requesting a recommendation.

OLDER MODELS (late 70's to early 90's)

Your handbook will state to use only Porsche Approved oils - well, they would say that wouldn't they.

Your handbooks will list older API spec oils such as SF, SG, SH, SJ etc however, All API ratings are backward compatible. Therefore, an SL rated oil will be just fine for an SH, SG or SF rated vehicle. However, on a newer vehicle that calls for an SL rated oil, it is not recommended that you use an oil that does not indicate that it meets the SL standard.

A quick point about API specifications.

API specifications are minimum specifications for oils. They exist for your safety so that you have reasonable assurance that an oil will "adequately" protect your engine. However, these are not, by any means, a standard by which you could determine whether an oil was good or not. As an example, you'll find that even a cheap oil which costs next to nothing will most likely carry the API SL rating. That should tell you something about how hard it is to attain that rating

Moving on, your handbook will have a chart which will list data something like this -

-10 to +40 degC 20w-40 or 20w-50
-15 to +40 degC 15w-40
-20 to +35 degC 10w-40 or 10w-50
-25 to +20 degC 10w-30

"All year round fuel economy oils"
-35 to +40 degC 5w-40, 0w-40

For the UK climate there is a wide range of oils that you can consider but you should take a couple of factors into account before making your selection and they are as follows:

Age of vehicle
Engine condition
Use of vehicle (road/track etc)

The reason to consider these is that older engines tend to like thicker oils as they tend to quieten down the components and older pump designs are inefficient.

If you are using the car as a daily runner it's a completely different story to using it on a track where the engine will be more stressed and running higher temps.

The Quality of the oil is important

Moving onto the most important factor in selecting an oil, it's a cost/benefit equation.

The pecking order for quality is from worst to best as follows:

Mineral Oils
Hydrocracked/Molecularly modified mineral oils
Poly alpha olefins (Synthetic)
Esters (Synthetic)

As I have mentioned before, all oils "shear" or thermally breakdown with use but not at the same rates.

Mineral oils require the most frequent changes and Synthetics the least. Synthetics are not petroleum based and therefore more pure and uniform making them more thermally stable as a basestock.

The Viscosity improvers in Mineral and HC/MC oils which are required to meet wide temperature ranges have a tendency to "shear" with use meaning that the oil will not retain it's upper viscosity.

So, all that explained, it's important to note that oils are sold in all viscosities and made up of all different basestocks, for example.

You can obtain a 10w-40 mineral, HC/MC or Synthetic but without doubt if you want a good 10w-40 the Synthetic is the best choice should you want the best protection over a longer period.

So, what's best for older Porsches?

Viscosities such as 10w-40, 10w-50 and 15w-50 would be the best choice. Stay clear of sae 60, firstly because it's not recommended and secondly it's too thick which can cause "oil drag" and slow circulation.

As a grade 10w-50 is a good selection as it gives better cold start protection than 15w-50 but also gives the same high temperature protection of sae 50.

Look at true synthetics as they are more "shear" stable and therefore better for those times when you wish to do a bit of "spirited" driving. A synthetic should contain poly alpha olefin or ester, the best ones are a blend of the two.

NEWER MODELS (993, Boxster, Ceyanne etc)

These cars are much simpler from an oil selection point of view and here I would recommend following your handbook closely and using Porsche Approved Oils.

In almost all cases, they call for "all year round" type oils such as 5w-40, 0w-40 or 0w-30.

Recently we discovered that Porsche are no longer approving anything other than 5w or 0w oils for use in the 993 (disconcerting as we know of owners using 10w-60 oils in their 993's).

The factory fill oils on all new Porsche models for the last few years has been 0w or 5w oils so you would be advised to use these thinner oils.

These oils have some benefits over their heavier counterparts.

Better Fuel Economy
Better Power delivery (less oil drag etc)
Required to meet new emissions

So, what would we recommend here.

Use Porsche approved ones, if it doesn't say so on the bottle don't use it. (we have a range of approved ones) Also check your handbook before buying.

The issue of quality still arises and as mentioned above the use of "true" synthetic oils is a must to ensure that your engine is getting the best protection.

Hope this helps

Simon

 

Looks like the typical cop out. Like so many who do not understand oil, the recommendation of : "Use Porsche approved ones". Absolutely brilliant reasoning. LOL!

 

elaborate!

 

Simon makes no technical or other analysis of what oil is BEST, but simply states to use what Porsche recommends. Those of you you have read my posts on the proper oil to use have been exposed to many argments for and against using a specfic weight of oil.

I continue to beleive that high mileage engines that only use the 0W40 Mobil oil in hotter climates will experence problems (maybe catystrophic) as valve guides, bearings and lifters wear prematurely due to insufficient oil protection of these componants.

As these compnants wear and their fit becomes looser, there is an increased chance that a crank or cam bends, etc. Or even worse, a ring or 2 shatters and starts a sequence of events that will destroy the entire engine.

JMO of coarse but is a result of many years of experience,