1996targa

I just looked over my receipts for an oil change that I did a few weeks ago at an authorized Porsched dealer in the San Francisco Bay Area and realized that the Porsche dealer used 10W40 Mobil 1. I recall that this is a different grade of oil than what my previous oil changes have used: 15W50 Mobil 1.

First question: Will the 10W40 grade of Mobil 1 be harmful to my 993's engine?

Second question: Is 15W50 considered a 993 engine oil standard? If so, why?

Third quetion: Is there a logical reason the Bay Area Porsche dealer uses the 10W40 grade of Mobil 1 instead? Local weather? Average driving conditions? Others?

Fourth question: Should I go back to the dealer and request an oil change back to the standard grade of Mobil 1?

Your advice would be much appreciated...thanks in advance.

FlyYellow

mobil 1 15-50 - that's what i use.... it is what is recommended from the factory and what most seem to use - good enough for me.

cheers,
boris

1996targa

Boris, thanks for your input.

BTW: I just went to the Mobil 1 website and found that Mobil 1 10W40 is actually "Mobil 1 MX4T 10W-40 Motorcycle Oil"! If that is what I've been driving around in for the past 1000miles, is that bad news? I also found many websites that say 10W40 is actually bad oil for cars, but o.k. for motorcylces. Is this also true?

How can an authorized Porsche dealer put 10W40 in my 993 if the oil is intended for motorcylces? What should I do? (Instinct says go to an indepedent Porsche shop and put in 15W50, but can I get my money back for the last 10W40 oil change?)

STLPCA

There are dozens of threads addressing your questions about M1 oil viscosity. Bottom line is you'll be fine w/10W40, although M1 0W40 is among those that Porsche presently recommends for your car. Are you sure it wasn't 0W40? If you track the car or live in a particularly hot climate you should consider using 15W50. Many here, including me, use 15W50 all year 'round (incl freezing cold winters) & have not had any issues. However, if I changed my oil twice/year I would use 0W40 for the colder months & 15W50 for the others. My car sleeps in a heated garaged. Much, much more if you do a search.

PCA Tech Section - 993 Oil Viscosity Recs

1996targa

Dan, thanks for your input. Here is what additional info I found out:

I called the Porsche Dealer this morning and asked them to check their records for when they last changed my 993 oil. Their computer records indicate that my oil change was done with 'normal' Mobil (non-Mobil 1) 10W40, as opposed to using Mobile 1 0W40 (which they use for all the Porsches they service). They have normal 10W40 because they are also a Mercedes dealer and some of the Mercedes use normal 10W40.

The service manager insists that the mechanic must have used Mobil 1 0W40 for my oil change, and that the 10W40 record was a typo. They offered to change the oil again with Mobil 1 0W40. They said they do not use 15W50 (which I prefer).

What I plan to do on Monday is go to my idependent mechanic and get an oil change done right using Mobil 1 15W50. While I get the new oil change, is there any (easy) way I can check if the oil the dealer had used was normal 10W40 or Mobil 1 0W40, e.g. sample it and then send it to a lab or back to Mobil Corp. If there is a way to find out that they had infact used normal 10W40 instead of Mobil 1 0W40, what compensation can I/should I seek from them. I already asked the dealer for a refund on the 10W40 oil change ($225) so that I can do it right elsewhere, but the service manager already said no.

Also, I've put 1000 miles on my 993 since the 10W40 oil change. Could I have damaged my engine with normal 10W40 oil in it? Should I even be worried about this or am I just being too paranoid?

Thanks for your comments

Newbie

Ray Calvo

Been using Mobil 1 0W40 for several years in both Audi & 993. No trouble. Use it on the track in the 993 also.

STLPCA

Easy test: synthetic tastes different (don't ask how I know)

Were I you, I'd just let the dealer do a change w/0W40 M1. You should discuss the issue w/the dealership's owner or GM. I think a "customer relations" price adjustment is appropriate for your hassle. However, barring highly unlikely circumstances, push comes to shove your "damages" will be limited to the cost of the dealer's bill. BTW, were you charged for M1 or dino? Big difference in price.

IMHO 1,000 miles w/new dino 10W40 won't hurt anything.

Perhaps Steve W will add his opinion.

chris walrod

Doubt you have any damage related to the oil in your car now. In my mind, the issue would be IF they used synthetic or not? If not, $225 is all the more reason to DIY..

Not sure if oil labs could tell whether or not what type of oil it is?

Anyone else know?

Traffic53

i'd be frightened. your engine is probably screwed dude.

maybe you should sell that targa while you can, you know...to me.

rockitman

Whether it's 10w-40 or 0w-40, both are just as thick as the other at temp...40 weight, so there is no advantage going with 15 for the low number. Most engine wear occurs at startup. You want the thinest oil so that it gets pumped to all the internal parts the fastest. 0w is quicker than 15w, hence less wear and tear. :-)

Steve Weiner-Rennsport Systems

Hi:

As you can see, the subject of oil generates many opinions,...

Porsche dealers (and others) tend NOT to buy many grades of oil for servicing the wide range of cars that come through the door as a matter of expediency. In short, its a "one-size-fits-all, sort of thing.

You will not damage anything using thinner oils in your 993 (uncless you go to the track in hot weather), but we do not use nor advocate using the 0w-40 and 10w-40 oils in 993's unless the outside air temperature is below freezing.

996 and later Porsches do very well with 0w-40, but the air-cooled cars really do better with 15w-50 unless its very cold outside.

Bottom line; if you live in a climate that sees temperatures over 70 deg at this time of year, you should use the 15w-50 especially if you do any track events.

1996targa

thanks for the input guys...very helpful! I think I will go ahead with a new M1 oil change.