Macster

There's more: Since the Turbo has a dry sump oil system the engine/oil must be hot and the engine running at idle and the car stationary and level before an oil level check can be done.

Sincerely,

Macster.

Gator996

So if I am using the dash indicator, what is a proper level for it to indicate? I read somewhere that some let it get to the bottom bar? I know it's bad to overfill.

Macster

Well, between the min and the max lines.

However, that doesn't take into account this represents a considerable difference in oil quantity. IIRC approx. 1.5 liters or 1.6 quarts of oil.

This means with the oil level at the max line there is say 8 quarts (well, there's more than this in the engine counting the filter, oil cooler, and so on but I think my point will be clear) of oil in the engine.

With the oil level at the min line there is only 6.5 quarts of oil in the engine. While there is no harm in running the oil level low there is less of a safety margin should the oil level go even lower.

The oil level sensor is not intended/designed to indicate how much extra oil is in the engine, only that the level is over the max. level, neither is it intended/designed to indicate how much under the min line of oil there is in the engine.

My philosophy is I want to run the oil level closer to the max level without going over, within reason. I'm not going to add oil the minute the level drops one bar from max.

But I do want the engine to have as much oil in it as it was clearly designed to run with but no more.

I do not ever use the lowest bar flashing as a sign to add oil. Somewhere -- maybe in the owners manual (I do not have one handy to consult) -- doing this is cautioned against.

Now granted some engines use more oil than others. This is natural.

In my case, my Turbo uses a bit less than a quart every 5K miles. (The Boxster about the same believe it or not.)

So even though the oil level starts out at the max line (but not above) I do not add any oil until the level has dropped a couple of bars, then I will add oil but just enough oil to bring the level up to the bar just below the max bar or maybe even the max bar.

An exception to the above is that if I'm heading out on a longish drive, starting out on a hundreds (or thousands) of mile road trip, I'll top up the engine oil to the max line even though the oil level may be just 2 or even 1 bar below the max line level. Also, I make it a point to put a full (and unopened) bottle of oil in the front trunk just in case.

So if your engine uses some oil you can let the oil level drop a few bars if you want before topping the level up. But I repeat I would never ever let the oil level get so low the bottom bar was flashing.

To me, even though some do this and they have not reported any engine problems arising from this practice, I simply choose not to run the oil level that low.

Sincerely,

Macster.

Gator996

Excellent explanation and I thank you!

Thundertub

+1 exactly what Macster said.

The only thing I would add is that I make sure the oil level is at the top line before I go to a track event. Never over that line, but always up to that line so that I am far less likely to suck air into the oil pick-up in the sump when going through long hard corners.

mcipseric

Isn't it risky to fill the oil to the top before a track event? Don't you need room for expansion?
On my 993, filling to the top is a big no-no as it will surely expand and start sucking oil into the intakes and you will get a bunch of smoke. Granted, the 993 is a dry sump system.....
I am new to the 996 and and my 996 is a dedicated track car. I have always been keeping my oil level at the middle mark on the dip stick. No higher.

logray

Here's an interesting fact for you:

My 3.4L core 3.6L rebored & rebuilt engine required nearly exactly 10.8 US quarts to get the dipstick to read 3/4 full, which is about where I like to run it. Of course, the engine was nearly completely dry aside from some start up lubes.

The stock 3.6L takes less oil.

But in the specifications I thought it was interesting to discover more conversion errors (there are many in the work shop manuals). Here's what it says:

---------------------------------
Engine oil quantity: Approx 10.25L (2.22 imp gal)
Change quantity: Change quantity 8.25L (1.79 imp gal)
---------------------------------

10.25 liters is actually 2.25 imperial gallons, and 8.25L is actually 1.81 imperial gallons.

10.25 L = 10.83 US quarts = 2.71 US gallons

Thundertub

Apples/Oranges. Completely different oil systems.

996 is a WET sump, which means that the minute you start it, some oil immediately starts to leave the sump to go to work. The sump is not full again until well after you shut it down and all the oil has drained back into the sump. You check a wet sump system when the oil is cold, before starting, and after standing, preferrably overnight. The measurement is in the sump.

You check a DRY sump system by heating up the engine and oil first, then leave it running at idle a few moments to allow the oil pump to return the oil to the OIL TANK. This is where expansion could be an issue for overfilling. The measurement is in the TANK.

Wet sumps return oil to the sump... SO, when you start with a properly full sump, shortly therafter, a lot of it isn't in there when and as long as the engine is still running. The higher the RPM the less oil in the sump at that moment since it is pumped out under suction, and returns more or less by gravity.

Simplistic response, I know.

996_North

Great, thanks Macster. You and Thundertub are great at helping out newbies..like me. I appreciate it.