wrljet

The thing I find ridiculous about the RMS problems is that Chevy V-8s used a piece of cotton clothesline rope for their rear main seals for years and they didn't leak or need replacing more often than the oil they held back.

I use Mobil 1 in minivans and other motors and don't have seal leaks.

Porsche has a decades-long history of taking decades to correct engineering mistakes. The 911 chain tensioners are an example. Plenty of other car companies managed to tension chains reliably without fanfare.

Bill

marlinspike

First, all engines burn some oil, there's a very detailed GM TSB you can look for if you care to. Yes burning a significant amount of oil does waste some power, but I know my parents Porsche doesn't burn a significant amount of 0-40. Second, thicker oil than necessary wastes hp too. Third, this is a direct quotation from the PCA website "The 15-50 is just too darn thick, and the hydraulic lifters won't pressurize when the engine is started & run cold. In many cases, the engines will be down on power, will be low on compression, and will usually make significant if not alarming ticking noises."

Here's another one "There is a strong possibility here that if you used Mobil1 15-50, that can cause the hydraulic lifters to fail to pressurize. That in turn will cause the engine to fail to achieve compression, and it will be difficult to start and won't run well until it finally warms up. That is why that weight of Mobil1 is no longer approved by Porsche (for anything but race cars without hydraulic lifters)."

I really don't know where you get that hydraulic lifters prefer thicker oil. You say you have hands on experience, but this leads me to doubt you've ever torn down an engine.

1999Porsche911

You can find quotes (just look in the owner's manual for the early 996's) directly from Porsche that 15W50 is fine for hydraulic lifters. So why did they say it was fine then and not now? Why did they deliver many of the 996's with 15W50? Were they delivering a car with an engine that didn't pressurize the lifters? Wow, I can't believe the Porsche engineers screwed up! And to think..they are the experts.

Stop reading and start doing and you''ll learn what is correct and what is marketting. Take a look at the timing variance on a 996 using 0W40 versus 15W50. It doesn't lie.


Hydraulic lifter have been in cars long before synthetic oils came to market, let alone multi-viscosity oils.

bgiere

1999, you are very,very wrong as usual. The amount of mis-information you spout about lubricants could fill a book! I'll say what Doug and others may be too polite to say: Quit giving people blatantly bad information that could damage their expensive engines. You need to lay off the oil advice. You are in way over your head on this particular subject. Stick to what you know instead.

Benjamin Choi

It's been really entertaining to read some people are justifying at length, laced w/ tenacity why they're not using the oil that the factory a.k.a. Porsche engineers are advising that we owners use on our 996 911s. It's comical and better yet it's all free to read.

I just changed the oil with M1 oh dub forty. How do you like them apples?

1999Porsche911

Porsche does not advise, recommend or otherwise suggest that you use 0W40. It is simply 1 of many brands and grades of oils that are on their SUBSCRIBED approved list. You can just as easily state that Mobil 5W50 is the oil that Porsche wants you to use since that is also on the list. People only read what they want.

gota911

OOPS! You are right, 0W-40 is what you call "mobile water." I was not trying to make it sound like you had never recommended 10W-40. My mistake on the oil weight!

BTW - My post was TOTALLY in jest! It was intended to be a little satire on the great oil debate.

wrljet

Isn't it currently the factory fill?

1999Porsche911

Yes, and the financial encouragement given Porsche by Exxon does not play any role in that decision. You can look at the different engine manufacturers around the world and easily identify who gets the most financial incentive from which oil company. IF in fact Mobil 0W40 was the best oil available, then it would be a no brainer for all engine manufacturers to use it. However, many must think that Pennzoil and Castrol and Shell are better than Mobil since they fill their engines with them.

Just like the tires that come with a car, oil manufacturers provide incentive to the the car companies to get their products used. This, by itself does not mean the products are bad, but it is a large part of the decision process.

And, do not forget the emission requirements these companies must meet, including gas mileage, A thinner oil may not be the optimum oil to use, but it gets their MPG's up. Changing your oil every 20,000 miles may not be the best for your engine, but this recommendation puts them in compliance. Keeping the same coolant in your engine for the life of the car may not the best for your engine, but, again, the car company must comply with emission requirements.

The point is, you would be niave to belive that a car manufacturer does not make decisions that compromise quality and longevity in order to meet government standards.

cdodkin

For those that have the time, or just want some info on oil, suggest you download the following doc:

http://www.trustmymechanic.com/motor-oil-bible.pdf

It's a long read, but it's a whole load of motor oil info in one place.

bgiere

As far as extended oil change intervals....Europe has been using synthetics for decades and the OCI's (oil change intervals) have been 10,000 plus for many years. If you doubt the capability there are plent of used oil analysis tests avaible for viewing at bobistheoilguy.com....many are Porsches using Mobil 1,Motul,Redline,etc....10-15,000 miles is not a long OCI...it's just that we are used to 3000 miles...10,000 miles or 2 years for an OCI is pretty darn reasonable for most of us if using a high quality synthetic. It is your money and your decsion of course, and if it makes you feel better,then that's great too!

1999Porsche911

Yeah, but if your change your oil every 10,000 miles, you are disgarding Porsche's current recommendation of every 20,000 miles. How can you do that. Are you saying that you know more than Porsche engineers? If you follow their recommendation for one thing because they are the experts, I have to assume that you would follow them for ALL recommendations otherwise the "expert" arguement does not hold any water.

gregroselli

On a side-note (seeing as how all the oil experts are in one place in this thread), if my 996 were burning oil as opposed to leaking it, could that make the fuel appear too lean/rich to the O2 sensors enough to trigger my CEL? Just trying to think outside the box here....

1999Porsche911

Most likely not. Your computer would adjust for the condition. Over time, the 02 sensors may get coked up sooner, but until then, they will adjust.

ltc

From now on, the use of the word "oil" is