discoganya

I know, I know, this has been discussed to death. I've read almost all the threads, but I still can't make up my mind.

My Indy says they've had great luck with 15W50 , so he recommends getting it. My car has always had 0W40 from the dealer till now. The viscosity difference is about 21% at 100C (running conditions) but almost 56% at 40C (cold start). Keeping in mind the approaching warm weather ...

1) Should I make the switch? Has anyone else made the switch? Does the car feel any different ? (e.g. https://rennlist.com/forums/996-forum/292838-i-m-running-15w50-and.html)
2) Will it cause any problems in the short term (i.e. suddenly changing the type of oil)?
3) Will it cause any problems in the long term (i.e. seizure, more wear and tear, etc)?

1999Porsche911

NO!!! Don't do it! Porsche does not approve it! It won't flow fast enough! Your engine will blow up! You will lose power! Your variocam will not work! It won't start because it is too thick! Your valves will lock up!, etc, etc, etc.

All these reasons, plus dozens more will be given to you not to use, what I consider, is the proper oil for your engine in moderate and higher temps. Those who will attack you will not provide any evidence to their claims (maybe a link to a website or 2) and will not accept that a large percentage of these engines regularly run with the 15W50 with no problems whatsoever along with the added benefit of no lifter noise, less chance of leakage, better compression, less or no oil burning and smoother operation of the variocam.

So, it is up to you. However, do not tell anyone that you make the change as you will be forever banned from talking about oil again on this forum.

It is, however, a no brainer to NOT use 0W40.

rcg412

1) I made the switch in my 01 at 75K miles, based on mechanic recommendation. Car was slightly smoother... otherwise no change.
2) No - many people run 15w50
3) Doubtful... would imagine though thie higher viscosity would prevent more leaks and may provide slightly better protection but #3 is purely opinion.

spiderv6

Did you see the Excellence article (last month I think) on oil? It's worth a read and I will stick with 0W40 after reading it.

bgiere

Whatever you do, 1999, don't let any facts get in the way of your stellar advice!

pl

There’s a fundamental flow in that article.
It doesn’t mention anything about oil analyze.
To recommend oil/oil change interval without some hard data from oil analyze is not convincing.

LVDell

1999Porsche911

Been waiting along time for some of these "facts" you keep mentioning? Having trouble finding some, are we?

bgiere

No problem finding 'em...You have a problem accepting them...wether they are from me or anyone else...You should go back and read some of your own prior posts and some of the responses you generate from others...now that is truly worthy of a laugh! I think maybe you do it for entertainment value....

CosmosC4S

My indy mechanic also recommends 15W50 for all the Pcars he works on.
I've not had any issues using it, no lifter noise complaints, and I had excellent results from a compression test.
OH, and I have 80k+ miles and running...

I did question him on his choice of 15W50 over 0W40,
He said STFU, coz' he knows better than I do.....

discoganya

C'mon 1999Porsche911 ... I've read your comments about a 100 times. I've read all the counter arguments, all the rebuttals and all the "hard facts".

Who else has real experience with 15W50 (like rcg412 posted)?

Thanks rcg412 & Cosmos, BTW.

nycebo

Seriously, couldn't you have done a more extensive search on the forum a read the sideways-8 posts detailing everyone's opinion? It's like Talleyrand once quipped, "If we go on explaining we shall cease to understand one another."

450knotOffice

Oh, yea! Here we go again.


FWIW, I talked to a friend who is a mechanic at Newport Porsche here in SoCal and asked him what HE and his fellow mechanics feel about 0W40(as opposed to the corporate stance). He unequivocally stated that he feels it is the best oil. He's seen no problems with it and really does recommend it. He doesn't feel the old recommendations are bad, just that the newer viscosity is a better idea.

I also had a nice talk about this with the owner of the independent shop I use, Hergesheimer Motorsports, and he agreed. He also uses 0W40 in his shop. He also said there is nothing wrong with the thicker oil, just that the lighter oil is better for these engines.

So I use 0W40.

LVDell

Sure would be great if we could get the 5W-50 here in the states.

nycebo

Alright, real experience? I had 0W-40 and switched to 15W-50. I noticed nothing except the car seemed to get worse mileage. I'm switching back in the spring.