95 C4 993

Everything I needed to know about oil, I learned from Wacky Packages.

Steve Weiner-Rennsport Systems

Everyone has an opinion about oils based on experience and this subject is largely regarded as a stepchild to religion & politics in many places. I would recommend listening to the people who have been building engines for a long time.

You may call me anytime to discuss oils as I really don't wish to subject myself to flaming on this,... (Its already happened in the past).

That said, I would tell you with any hesitation that 0w-40 is totally inappropriate for any air-cooled 911 engine unless the outside air temps are consistently below freezing. Further, there are really much better 0w-40 products than Mobil 1 to use in this case.

matt777

Thanks Bill! That is exactly what I needed to see. I didn't find it on the Canadian site. The ZN and P levels are higher than I would have guessed.

ps I think I got hosed at the dealer on the filters. $73 plus tax? They are actual Porsche logo filters. If I had planned better I could of got them elsewhere although I might have spent the savings on shipping. Not a big deal though.

face-ache

ahhhhh, It's about time we had another oil thread...

mongrelcat

I gather from reading the mega thread on Pelican that Mobil changed the 15w50 formula a few years back including reduced ZDDP (Zinc and Phosphorous) levels. Subsequently they have changed the formula back, as indicated in the data sheet above and VOAs from 2 years ago. Although the 15w50 is SM oil it is not required to have lower levels of Zn/P (~800ppm ) by nature of it being 15w50.

Has anyone seen a recent Virgin or Used Analysis for M1 15w50? I checked the Pelican thread and BITOG and didn't come up with anything.

BTW, I'm using it, as it was recommended by 4 of 4 mechanics that I asked, and it's what has always been used in my car (in whatever incarnation was available at the time.)

mlk118s

I would try the 0w40 M1. I from about October '08 to late January of this year I drove my '95 Cab daily with 15w50 M1 in it. It is a great oil and worked well. When the outside temp was above 65F I couldn't recommend it more, but as the weather got colder, it took a LOT longer for the car to get up to temp. If you plan on driving the car in cold,(You are in Canada correct?) or dare I even say cool weather you really have to run the car hard to bring it up to temp within 20 min of start up, this of course increases wear.... I suspect the M1 0w40 which is what the cars new owner is running should be ideal. He is an engineer and rates it highly. Also, keep in mind 964 series cars are typically known to run hotter then 993's, so the 15w50 may be more to their benefit. Just my 2 cents. Mine was a '95 OBD I,Pre-VarioRam with 56k miles..not sure it matters but want to give as much info as i can.

anto1150

Steve,

I've always used M1 0-40 as adviced from Porsche and never noticed oil temp raising over the average, even in >36 °C external temp.
I drive the car in wide range of temperatures, say -2 to 38 °C. Would you advice a different oil grade?

grazie
antonino

Slow Guy

Guys, just about all of these questions have been answered in previous oil threads, this one being the most recent:

anything-new-on-the-mobil-1-front

I can understand Steve's reluctance in going through it again. He did an awful lot of typing in that thread.

matt777

With the potential of a $10k+ engine overhaul bill I think long discussions on suitable oils are appropriate. Some chose to stay away due to horrible flashbacks of sifting through very long threads.

anto1150

Bill,

thanks, I missed that one...!

GaryB

John Walker in Seattle did my last oil change. He used the Mobil 15-50, BUT also added a half-can of Comp Cam to increase the ZDDP levels.

Rinty

That's the issue, as I see it. What is available, on the shelf, in Canada for air cooled Porsche owners . I've never seen Brad Penn or Swepco at any retail outlet here. And the sense I get from the oil threads is that Mobil 1 might not cut it.

ilko

Why not just add a little bit of GM Eos or ZDDPlus in the Mobil 1?

bart1

I get my BP from a guy when I see him at the track or he meets me close to his place in Nashville. Only $5 a quart, without any additional tax, shipping, etc.

I'm sure there is a way to get in in Canadia if you try.

Steve Weiner-Rennsport Systems

Good question and I'm glad you asked,....

Oil chemistries are quite complex as each element and additive carries some side effects to be countered. Higher levels of ZDDP tend to leave excess deposits on pistons, rings, and ring lands which will restrict their ability to rotate and seal. Oil companies deal with this by adding a carefully balanced blend of detergents containing Magnesium, Calcium and Sodium compounds to remove and scavenge these deposits.

Indescriminately fortifying an off-the-shelf oil with additional ZDDP creates a big internal problem unless one performs sufficient oil analysis to know what to use, and how much of a detergent package to add. This is not a DIY exercise.

Racing (and break-in) oils containing very high (>1400-1800ppm) levels of ZDDP are not left in the engine more than a weekend so they do not require a robust detergent to keep the pistons and rings clear of deposits.

My best advice is to buy an oil that already contains a robust package of the additives you need for your engine. Thankfully, there are good products to choose from.

I hope this helps,...there are several publications you can buy from the SAE on this subject that explains this in great detail. Its quite an education,........