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Which GT3 engine oil?

Roro

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1 Oct 2010
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7,466
Would heavier oil protect my engine better now I'm doing the odd trackday now and then? Or does it depend more on how hard I drive the car (I don't... Really)?

Mobil 5w10 I think is standard, but why shouldn't I use something thicker?

Surely thicker oil would provide better lubrication for the metal stuff that goes round and round really fast inside the engine when it's on?

(.... sorry but that's about as technical as I'm capable of getting :oops:)
 
I looked at this and to be honest I went back to a 0-40 from the car having 10-60 in. The Porsche approved oil is 0-40 and 5-40 in high temps. Ie when hot they are both 40 rating. A 60 rating when hot is nearly twice as thick as the 40 so while you will have higher pressures the flow rate is likely to be down and the pumps will be working harder and be more strained.

On that basis I would leave alone unless you see very high temps with a marked drop in pressures below the Porsche 3.5bar at 3000 rpm.

Certainly wouldn't put unapproved oil in if in warranty.


Just my opinion of course....
 
It is not twice as thick and there is more to it than the numbers.

This really is a doomed debate whenever it appears TBH.

Put in what you feel comfortable with - Personally I use Millers Nanodrive 10w 50NT without any issues. I spoke to the Hartech and Millers oils chaps directly and was more than happy with the answers and the science behind the answers.
 
Cheers for the responses chaps :thumb:

Not sure I understand why this is a 'doomed debate' :?:

The pumps having to work harder to push thicker oil around makes sense to me, so unless some upgrades are planned in those areas sticking to OEM recommendations for the car sounds sensible.
 
Ps - Fish thanks for the viscosity correction - I may have been mixing up with the oil I use in my 500! :eek:

:thumb:
 
Roro said:
Not sure I understand why this is a 'doomed debate' :?:

The subject comes up quite often and there are a number of people with strong but contrasting opinions on what the answer is. Since it isn't clear cut some of them will argue about it from dawn to dusk on the pretext that they are right and anyone who disagrees is wrong. The debate is considered doomed as pretty much every car forum that covers Porsche has done it to death without ever really establishing an answer.

But a summary for you is that Porsche GB always use 0w40 in everything regardless. The independents tend to use 10w50 or 10w60 for cars where the customer is tracking the car. Where you really want the heavy grade motorsport stuff is if you are making the engine work really hard - if you are at Spa or Silverstone and it is dry and over 30 degrees would be an obvious use case...

Oil connoisseurs will note that BMW approve only 10w60 for M cars and as a consequence the rev counter has those little warning lights for how many revs not to use until the oil is up to temperature. If you put it in your Porsche you really ought to behave likewise - look for about 80 degrees of oil temp before spanking it to look after your engine.

For a mostly road car with track time only a couple of times a year I reckon that you are probably better off to stay 0w40. Only once the car is doing regular track usage does this even really become a question.

But that is just MHO, and there really are a lot of people who will argue with it.
 
Having used every weight of Mobil oil from 0W40 through 10W60 in my engine pre-rebuild, empirical evidence would tend to indicate that using heavier oil results in no oil being required between changes (every 3-4K miles in my case). The 0W40 stuff runs out like water when it comes out hot & required smallish top-ups so I assume it is being burnt off by coming past the rings &/or guides. Although the main & scavenge pumps were replaced at rebuild, they were all operating perfectly after 85K miles (about 25K of which were on track). My take is that the weight of oil used is secondary to the frequency of changing it if you are going to look after the engine. I just feel that heavier oil seems to work better for my particular usage; YMMV ;)

Since Mobil discontinued their 15W50 Rally formula Motorsport oil a couple of years back, I have settled on Millers NT 10W50 which gives me a healthy 5 bar at 3K RPM even when hot. I put it in my E55 AMG at the last change (8K miles ago now) and again, no top-up has been needed. Using 0W40 Mobil (as recommended by Merc), I was topping up about 1 litre every 1500 miles - the AMG has done 110K miles.
 
Also consider BMW started using TWS to improve the oil useage problem in E39 M5s not as a performance advantage.

My 6.1 has been on 10W60 from the I dependants for a longtime but this year my Indy used 5W40 Porsche approved, it's noticeably quieter on start up but the oil pressure at hot idle is definitely lower (about 0.5 Bar infact), I think at the next service I might go for a 5W50 but the very best Ester 5W40s nowadays are much, much better than they were a few years ago.

The true answer is without monitoring actual oil temperatures it's hard to make an informed choice.
 
This is very interesting. I didn't know that this was such a contentious issue!

Why is oil usage / consumption a bad thing?

If the car was burning oil and you were topping up now and then, wouldn't that mean the oil would be fresher overall, than oil that was never topped up?
 
Go to www.opieoils.com and ask there what they recommend. They will tell you what they think is best etc.

As for oil usage, it could be numerous things regarding consumption, some could be just general usage others could be that your engine internals are *****
 
What do they put in the Cup cars?
 
s2000db said:
What do they put in the Cup cars?

0W40 generally. It's changed for every meeting so probably gets a maximum of 2 hours of running before it gets changed. Not really an option for a road car.
 
Good choice; that's what Fearnsport put in GT cars.
 
NXI20 said:
Good choice; that's what Fearnsport put in GT cars.

Nick, do you prefer the 10w50 you're using now or the 10w60? I'm currently using 10w60 as per Fearnsport but about to do a change.
 

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