Dumb question - oil top-up

[John996C4S]

So, 18 months and 9000 miles into owning my 996 C4S I need to top up the oil. It started off at the top notch of the electronic indicator, and is now one notch into the lower half.

I am wary of overfilling. What's the recommended procedure, and is there a rough guide to how much oil 'per notch'?

I'd also be interested in any views on whether the consumption is excessive.

Regards

John

[RiccardoG]

Normally top to bottom is 1L (this applies to most cars).

[Trev450]

Iirc its about 0.3 of a litre per notch.

Your oil consumption doesn't sound excessive at all. Porsche claim up to 1 litre per 1000 miles is acceptable. I, however, would not be happy if mine was using that much.

[burman]

John if in doubt add a small amount and check it on the dipstick, which at least you have got, unlike my 997C2S.
I think you will only need something under half a litre.

[John996C4S]

Thanks all, much appreciated.

John

[6C4GTS]

IME each bar is about 200-250ml. A lot of owners keep the level 2-3 bars from the top to avoid any overfill catastrophes.
Have you not had an oil change in 18 months?

[John996C4S]

6C4GTS said:

IME each bar is about 200-250ml. A lot of owners keep the level 2-3 bars from the top to avoid any overfill catastrophes.
Have you not had an oil change in 18 months?

Nope, service due end of year so it will happen then. Only 9000 miles, and at that level I'm happy to stick with the 24 month schedule.

[Callughan]

6C4GTS said:

IME each bar is about 200-250ml. A lot of owners keep the level 2-3 bars from the top to avoid any overfill catastrophes.
Have you not had an oil change in 18 months?

Agreed and yep its 200ml.

At the minimum an oil change every year, more if you track or if you run it hard.

Mine would need top up every month or so.

[911mark911]

hi also another question to follow on from this, I am a new owner and need to add a little bit of oil (halfway) but don't what is in there already can you mix oils?

[Callughan]

911mark911 said:

hi also another question to follow on from this, I am a new owner and need to add a little bit of oil (halfway) but don't what is in there already can you mix oils?

Better to drain and put fresh batch in.

Not expensive and does the world of good.

[Rockster]

911mark911 said:

hi also another question to follow on from this, I am a new owner and need to add a little bit of oil (halfway) but don't what is in there already can you mix oils?

According to Porsche all approved oils are miscible. Porsche goes on to say, paraphrasing, you should use the same oil that the engine was filled with but in a pinch any approved oil will do. Better than running the engine with too low an oil level.

If you do not know what oil is in the engine you should. If you bought the car with the oil type unknown the first thing you should have done was have an oil/filter service done and ideally using an approved oil.

If the oil level is critically low put some approved oil in the engine, but then you should get the car in for an oil/filter service pronto and when you pick up the car and drive it away after, be sure you have two bottles of the same oil in the trunk handy to use to top up the oil level if necessary before the next oil/filter service.

[Pete Eroleum]

As burman says, always use the dipstick if you have one. 100% reliable, it never lies. Electronic indicators
are just indicators.

[anonymous-user]

John996C4S said:

6C4GTS said:

IME each bar is about 200-250ml. A lot of owners keep the level 2-3 bars from the top to avoid any overfill catastrophes.
Have you not had an oil change in 18 months?

Nope, service due end of year so it will happen then. Only 9000 miles, and at that level I'm happy to stick with the 24 month schedule.

Brave man. You're six months and a few thousand miles past a sensible oil change.

[John996C4S]

REALIST123 said:

Brave man. You're six months and a few thousand miles past a sensible oil change.

So the recommended service intervals are inappropriately long?

[anonymous-user]

John996C4S said:

REALIST123 said:

Brave man. You're six months and a few thousand miles past a sensible oil change.

So the recommended service intervals are inappropriately long?

In most owners experience yes. Talk to the people who have cars that have covered lots of miles without developing a thirst for oil, and there is no reason why a 911 should use any oil at all, and you'll find that they almost always change the oil annually at least and after 4/5000 miles.

It's well established that these are fragile engines, to say the least, so the minimal cost of an extra oil change once a year is well worth it.

[6C4GTS]

I change oil and filter at least every 5k.

[BertBert]

REALIST123 said:

In most owners experience yes. Talk to the people who have cars that have covered lots of miles without developing a thirst for oil, and there is no reason why a 911 should use any oil at all, and you'll find that they almost always change the oil annually at least and after 4/5000 miles.

It's well established that these are fragile engines, to say the least, so the minimal cost of an extra oil change once a year is well worth it.

Forgive me, but what is it about "owners experience" tells you this? They, like you, think it's better. There's no denying that there's no harm and likely to be good to come from frequent oil changes, but do we have more than that? Any evidence or even telling experiences of the Porsche interval being too long?

As for oil usage, the Porsche guidelines seem to allow for quite a lot of oil usage. How are they wrong and you know better?

I did say forgive me as it sounds like I am attacking. I'm attacking ideas with no basis in evidence!

Bert

[Callughan]

From 03 to 04 when the 2 year interval was introduced there were no material changes to the engine.

[anonymous-user]

BertBert said:

REALIST123 said:

In most owners experience yes. Talk to the people who have cars that have covered lots of miles without developing a thirst for oil, and there is no reason why a 911 should use any oil at all, and you'll find that they almost always change the oil annually at least and after 4/5000 miles.

It's well established that these are fragile engines, to say the least, so the minimal cost of an extra oil change once a year is well worth it.

Forgive me, but what is it about "owners experience" tells you this? They, like you, think it's better. There's no denying that there's no harm and likely to be good to come from frequent oil changes, but do we have more than that? Any evidence or even telling experiences of the Porsche interval being too long?

As for oil usage, the Porsche guidelines seem to allow for quite a lot of oil usage. How are they wrong and you know better?

I did say forgive me as it sounds like I am attacking. I'm attacking ideas with no basis in evidence!

Bert

I'm not going to get into the old running in v not running in, oil consumption is OK v it's terrible debate but there is no doubt that Porsche, like other manufacturers, quote excessive oil consumption as being acceptable simply to stave off complaints from those that abuse their engines or get a poorly assembled one.

I know a number of informed owners running cars to high mileages under sensible regimes, that consume negligible oil. Common sense says that those engines have less wear than similar ones using up to a litre every 1000 miles or whatever ridiculous figure Porsche say is OK.

Frankly, the oil usage recommendation from them should be filed with their insistence that the M96/97 engines weren't flawed, that you really must use N rated tyres and that OPC service is essential.

[Rockster]

Pete Eroleum said:

As burman says, always use the dipstick if you have one. 100% reliable, it never lies. Electronic indicators
are just indicators.

Actually, no, the dipstick is not 100% reliable. The shortcomings of a dipstick are well known. The risk of it getting caught and not giving a valid reading, the messy aspect of using one that cause most owners to shun checking the oil.

The electronic e-oil level systems are very reliable and make it very easy to check the oil level. My Boxster has the dipstick but I can't recall the last time I used it. I rely on the e-oil level display. My Turbo doesn't even have a dipstick and I don't miss it one bit.