Porsche 911UK Forum

Welcome to the @Porsche911UK website. Register a free account today to become a member! Sign up is quick and easy, then you can view, participate in topics and posts across the site that covers all things Porsche.

Already registered and looking to recovery your account, select 'login in' and then the 'forget your password' option.

0W40 or 5W40?

RossJ

Member
Joined
25 Oct 2018
Messages
6
Hi All,

I have a 997.1 C4S that's done ~62k miles and I'm curious to know what the best oil grade is that I should be using?

The car's still covered by Porsche warranty and is being serviced at my local OPC, hence choices are limited to 0W40 and 5W40 based on what's in the manual and the approved oil list I've been sent by Porsche.

The folks at the OPC only use 0W40 and were a bit surprised that I'd think of putting anything else in the car, hence the question.

The internet (being the cacophony of voices that it can sometimes be) seems to suggest that if I use anything anything other than 10W50 (as apparently recommended by Hartech) my engine is sure to explode/get scored bores, but also that if I use 5W40 there's more wear at lower temperatures as the engine's warming up, although other specialists (Paragon Porsche, Revolution Porsche and Precision Porsche to name the ones I found online) seem to recommend 5W40.

Any ideas?

Cheers
 
As DeMort says 5W40 up to about 70k then consider swapping to 10w50 but TBH if your happy at 5w40 thats better than the brown water the OPC want to use .
Dont forget when your talking to the OPC they are now only fitters theres very little proper time served knowledge there . they just change things that are broken they cant fix a broken part like an indie could try and do. So I am not surprised you got a look of surprise from them as their little computer won't tell them how to do that :floor: :floor: :floor:
 
Cheers chaps, appreciate the advice! The guy at the OPC did tell me that they only recommend 0W40 because they have a literal vat of the stuff and seemingly no-one typically questions the oil that goes into their cars so that's all they use. Guess they also service newer cars for the most part.

So, the next question is, if 5W40 is good, then what 5W40 do I use? The Porsche approved list (that I have to choose from) has probably a hundred different variants from myriad manufacturers and I've no clue what makes one 5W40 different from another 5W40?

I can post the list if it helps, just it's massive.
 
Hartec

If it was me I would use what the guys a Hartec recommended, Top engine Bulder who have done a lot of research and testing on the 997.1 motor .They know a great deal about Porsche motors.
 
Re: Hartec

tgdesign said:
If it was me I would use what the guys a Hartec recommended, Top engine Bulder who have done a lot of research and testing on the 997.1 motor .They know a great deal about Porsche motors.

Millers NanoDrive CFS NT+, I use 5w40 in the Boxster @60K and 10w50 in the 996 @109K :thumb:
 
In my 997.1 C4S I was using Mobil 0W40 up to around 60k miles and it was consuming a little bit of oil, say one third of a litre every 1000 miles, which is well within tolerances.

Since switching to Millers 5W40 I am currently at 66k miles with very little oil usage at all, so something is working well.... :thumb:
 
I use Mobil 3000 5w-40. I provided the oil to OPC at my latest service. I've found oil consumption has nearly halved since switching to this oil from the standard Mobil 1 0w-40.
 
Basic rule as I see it is
New car or low mileage = factory tight tolerances/clearance in the moving parts so a 'thin' oil is great 0/40 etc
Older car 60,000+ miles the tolerances and clearances are now larger due to use, so a 'thicker' oil protects better due to the more worn engine, and to be clear I'm not suggesting a 60k mile car is worn out, far from it but tolerances are more.
OPC recommend what's in the book but they also deal with mainly newer lower mileage cars
 
It's only thicker when it's cold. Once up to temp. 0w 40 and 5w 40 are exactly the same. My mates argument is thinner when cold is better as it reaches the parts in need of oil quicker on initial start up than thicker stuff :dont know:

Jury's still out for me. All I know is mine doesn't use virtually any oil, though it does use slightly less on the 5w 40 than 0w 40. Also, until last year mines run on 0w 40 mobil 1 all its life (around 125k miles).
 
5w 40 for me.

going to try millers 10w 50 at next oil change

mine is a 90k mile 997 3.8 which has been rebuilt at 83k.
 
Alex said:
It's only thicker when it's cold. Once up to temp. 0w 40 and 5w 40 are exactly the same. My mates argument is thinner when cold is better as it reaches the parts in need of oil quicker on initial start up than thicker stuff :dont know:

Jury's still out for me. All I know is mine doesn't use virtually any oil, though it does use slightly less on the 5w 40 than 0w 40. Also, until last year mines run on 0w 40 mobil 1 all its life (around 125k miles).

so scenario is, older engine and space between e.g. bearings
New 20 thousandths of one inch
100k miles 35 thousandths of one inch. (these are examples, Not actual)
Over night stood in the centrally heated garage, the thin oil would drain from the gap where capillary action used to keep it there ready for starting, the very slightly thicker oil will stay due to that very same capillary action, therefore every time you start up there is less wear on the older engine with the thicker oils, when hot I would say minimal advantage as the pump is sending high pressure hot oil to all the parts anyway.
Its just the initial start from cold.
maybe i'm talking my logical engineering rubbish :dont know:
 

Forum statistics

Threads
124,352
Messages
1,439,436
Members
48,708
Latest member
JLav211
Back
Top