Oil change
- Thread starter 911kev
- Start date
I have used Millers 10-60 and it has been great, I have now got Castrol 10-60 in and I think the Millers is slightly
better, My car feels a little smoother and seems to hold pressure a little better with the Millers, but it may all be in my head, along with the voices saying a need a supercharger!
better, My car feels a little smoother and seems to hold pressure a little better with the Millers, but it may all be in my head, along with the voices saying a need a supercharger!
paulf968
New member
as Dave mentions I am one of the people who vote for Silkolene PRO S 5W-40, been very happy with it for the last 4 yrs -- full synthetic and ester based (keeps its SAE rating throughout its life).
NB thicker oils do absorb more power due to higher oil shearing forces with our large cranks -- so if you want max bhp then stick to a high quality 40 grade -- if you want the ultimate in longevity for your engine then a 50 or 60 grade is the way to go
NB thicker oils do absorb more power due to higher oil shearing forces with our large cranks -- so if you want max bhp then stick to a high quality 40 grade -- if you want the ultimate in longevity for your engine then a 50 or 60 grade is the way to go
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sawood12
New member
Another vote here for Silkolene Pro S (i use 5w40). I'm not a great fan of using thicker oils to maintain pressure. It is the flow of oil over the moving parts of the engine that is important and not the pressure. Trying to blow a McDonalds Triple Thick milkshake through a straw will require alot of pressure but the resultant flow would be very poor compared to blowing water through the straw where pressure would be less but flow good. I tend to stick to the Porsche recommended grades (i.e. from 5w40 through to 15w50 for the UK climate and normal driving according to my handbook) and if oil pressure is not as it should be investigate why - it might just be a dodgy gauge or sender. By using thicker oils you may be masking a much more serious problem and exasberating it.
Neil Haughey
New member
ISTR the owners manual only goes up to 50 hot so in theory a 10-60 is outside of the recommended range? Having said that the table does allow for a 20-50 or a 15-40 for example. I have given up trying to decipher the best oil. I have used mobil 15w-50 in my S2 for a few years now and this has worked really well for me, the 968 currently has 5w-40 and as long as she doesn't burn much oil this summer I will probably stick with that. The list of recommended oils is pretty large just about anything and everything is on there but some notable exceptions was the dropping of Fuchs, don't know why?
Super_Marv
New member
I changed from Castrol RS to Millers CFS and found the engine smoother and a little more willing to rev too.
paulf968
New member
Hi - pb
Generally speaking, the possible problem with a 0W-40 oil would be if the engine or seals are getting a bit tired. Then oil leaks might develop or a bit more noise eg from the top end at start up (hydraulic valves taking a moment to get going) .
Mind you in winter that oil will help the engine turn over quickly on the starter motor.
There is another theory I have read somewhere -- that as our engine was really designed in the 80's, the tolerances are not quite as tight as they are these days and therefore a 5W-XX or 10W-XX would be more advisable. Personally I will not go lower than a fully syn 5W-40 for this reason.
If you have no probs and the oil pressure holds up nicely -- stick with it.
Generally speaking, the possible problem with a 0W-40 oil would be if the engine or seals are getting a bit tired. Then oil leaks might develop or a bit more noise eg from the top end at start up (hydraulic valves taking a moment to get going) .
Mind you in winter that oil will help the engine turn over quickly on the starter motor.
There is another theory I have read somewhere -- that as our engine was really designed in the 80's, the tolerances are not quite as tight as they are these days and therefore a 5W-XX or 10W-XX would be more advisable. Personally I will not go lower than a fully syn 5W-40 for this reason.
If you have no probs and the oil pressure holds up nicely -- stick with it.
hi paul,
yeah oil pressure is great with the mobil 1, even when really hot it is 3 bar at idle and 5 bar at 2500rpm, not really any noise on starting, it has 95K up it and uses a tiny amount when driven hard which is most of the time, although i religously wait till it's warmed up and use 2/3k rpm max till then. When kirkmans did the belts they commented on how oil tight the engine was, ie cam balance belt seals etc and they know the car from when the sutton coldfield OPC parts manager had it.
I'm planning on doing a few trackdays this year and I've booked two full days at spa in june with goldtrack and so was thinkng may be i should use something a little thicker. I might still do that, but mobil 1 is so cheap at cost co.
sawood12
New member
I don't subscribe to this notion that back in the '80's the tolerances were not as good. In the '80's (and before than) it was perfectly possible to manufacture bearings to exactly the same tolerances as bearings used in today's engines and the materials are essentially the same. I think that the reason engine oil has become thinner over the years is because oil technology has improved. You can now use thinner oils with the correct properties to fully protect the engine. It's the same reason why modern cars service intervals are not upto 20k miles despite the performance of engines being vastly improved over the years. I'm sure if today's oils were available thirty years ago then our cars would have been specc'd with 0w30 as most modern family cars seem to be.
I queried the chap at Opie oils regarding trackdays and he said as long as I only did a couple or three a year and wasn't driving really hard for a long period of time then a modern synthetic oil at the manufacturers recommended grade is fine. I guess you've got to use your common sense and gauge how hard you're driving your car. On the basis that you're usually only out on track for 20 - 30 mins at a time, and the first and last couple of laps are warm up and cool down laps, and in between you rarely get a chance to be fully on-it for a full clear lap let alone stringing a few laps together, then you're probably not working the engine as hard enough to really build up as high engine and oil temps as you think you are. I suppose the best thing to do is to ensure that your water and oil rads are flushed and clear to make sure they are working as efficiently as they can be and maybe even install an additional oil cooler to be sure. They are relatively cheap.
I queried the chap at Opie oils regarding trackdays and he said as long as I only did a couple or three a year and wasn't driving really hard for a long period of time then a modern synthetic oil at the manufacturers recommended grade is fine. I guess you've got to use your common sense and gauge how hard you're driving your car. On the basis that you're usually only out on track for 20 - 30 mins at a time, and the first and last couple of laps are warm up and cool down laps, and in between you rarely get a chance to be fully on-it for a full clear lap let alone stringing a few laps together, then you're probably not working the engine as hard enough to really build up as high engine and oil temps as you think you are. I suppose the best thing to do is to ensure that your water and oil rads are flushed and clear to make sure they are working as efficiently as they can be and maybe even install an additional oil cooler to be sure. They are relatively cheap.
Hi Scott I agree with the majority of what you say but I think I'll swap the oil for something of high quality of a little thicker viscosity before I go, it's two days of open pitlane. I know the circuit very well indeed and was only 0.5 secs off of the lap record for my class. Having been to a goldtrack day there before in my old mx5 I know even when it's busy there's so much room you dont really get too much tarffic, consequently you can really motor.
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