Jump to content
SAU Community

Recommended Posts

Some time ago we back to back tested Castrol FR 5W30 and 10W60 in a race engine (not an RB) on the dyno. Sure the race engine was built “loose” compared to a brand new “standard” road engine, but probably no looser than a 100,000ks’ old road engine. On the dyno there was very little difference in power output at all rpm ranges, with the 5W30 slightly ahead. But in real world conditions I don’t think you would ever notice the power or fuel consumption differences.

So I have continued to use the 10W60 in my road cars (and race cars) for the temperature safety margin it gives me.

:kiss: cheers :rofl:

PS; I didn't notice any significant oil pressure differences at normal operating temperatures, the oil pressure relief valve controls that.

Edited by Sydneykid

With the 5w40 Motul gear, over 3500rpm its a smidge under 6kgcm2... I should walk out to the car and have a look what units the std guage use.. lol

SK, to back up what you are saying I have seen on the net somewhere a dyno back to back with different oils in a subaru turbo thing, the castrol 10w60 actually made more power than some of the other lighter weight oils (splitting hairs type results, but none the less it wasn't less power), if I remember correctly better than the majority of 5w40/5w50 oils with the only one beating it being the mobil 1 0w40.

I would have kept running the 10w60 but was concerned with such high oil pressure, I must admit fuel economy is the same between oils.

Just cruising at 100km/h it was sitting damn close to 6kgcm/2 vs the 5w40 that sits on roughly 4.5..

Busky2k, I remember when whatsisname was running the motul 300v 10w40 in his close to 300rwkw rb25, he ended up moving to the 300v 15w50 as the 10w40 was not cutting it, how he knew this im not sure.

PS; I didn't notice any significant oil pressure differences at normal operating temperatures, the oil pressure relief valve controls that.

Yes very true , but it really depends on the engine too. Some go into relief just off idle. Others don't until 5000rpm etc. So different viscosities behave differently between engines. For example a 10W60 might go into relief at 4000rpm, but a 10W30 in the same motor might not go into relief until 6000rpm. So the latter oil would provide more flow for the same pressure.

Whilst the fuel economy benefits between thick and thin are small, they are definitely there but we're not talking say a trend you could see just over 1 tankful. For example, an ILSAC GF-4 rated oil must show 2% (IIRC) better fuel economy than a refererence fully synthetic 10W30. Moreover, many manufacturers in the USA are moving to 5W20 purely for fuel economy reasons. I believe people who would benefit the most from a thinner oil is one who does frequent short trips, where the cold viscosity differences between a 10W60 and a 10W30 are very large.

However I wouldn't say a thick oil would make you loose power compared to a thin on the dyno as the differences are down to the margin of error.

Cheers :D

Edited by Busky2k

Ive been using castrol R 10w 60 in my 33 since compliance...its only had 1 oil change so far at 5000kms ( due for the next 1 in about 2-3000km).

on startup, the pressure is at 3/4 of the stock gauge (6). when its warmed up and driving, it sits right on 4, and when stopped at the lights etc, it goes to 2.

None of that means anything to me, just thought i'd put it up for those who know what they're talking about.

justin911 uses the same oil, and his gauge shows those same readings in his 33 as well :D

personally i think 5000kms is too many between changes. but i am a catious mofo when it comes to maintenence as i punish the ring out of my cars i like to look after them as best i can in every other respect.

  • Like 1
Ive been using castrol R 10w 60 in my 33 since compliance...its only had 1 oil change so far at 5000kms ( due for the next 1 in about 2-3000km).

on startup, the pressure is at 3/4 of the stock gauge (6). when its warmed up and driving, it sits right on 4, and when stopped at the lights etc, it goes to 2.

None of that means anything to me, just thought i'd put it up for those who know what they're talking about.

justin911 uses the same oil, and his gauge shows those same readings in his 33 as well :D

My oil pressure is quite a bit higher than that, my oil pump is 'supposed' to be an rb25det pump.

First thing in the morning no matter what oil I use its up over the 8, well the only oil that was around 7.5 was the 10w30 castrol.

The idle is it sits on 2.

  • 4 weeks later...

lots of talk about pressure not much on viscosity...look at the cSt ratings of the 10W60 etc...compared with the 10W30...cold start is miles different...which is when 90% engine wear occurs.

on top of that a wide spread oil will need ot be changed more often due to the VII content to get the spread...never go past the POE stock oils such as redline and Motul 300v for example.

you op. temp visc. ratings will be similar in a 30 or a 40 60 is probably quite thick still...but the cold start is where u have a gain.

my 2 cents.

lots of talk about pressure not much on viscosity...look at the cSt ratings of the 10W60 etc...compared with the 10W30...cold start is miles different...which is when 90% engine wear occurs.

on top of that a wide spread oil will need ot be changed more often due to the VII content to get the spread...never go past the POE stock oils such as redline and Motul 300v for example.

you op. temp visc. ratings will be similar in a 30 or a 40 60 is probably quite thick still...but the cold start is where u have a gain.

my 2 cents.

for those that dont understand technical stuff, were you saying 10w 60 is good or bad?

is there any reason too high oil pressure is bad? mine is up at 85-90psi at idle when stone cold, and drops to 40-50psi at idle when warm, then hits around 80psi on full rpm under load. its a jun oil pump though, and im running the castrol 10w60 edge as well. it this just because of the relief valve spring being stronger in jun pumps?

is this a benefit ive got such good oil pressure or is there a downside to it?

Edited by CruiseLiner

I cant begin to tell you how good the formular R range is. used the 10w-60 on my GTiR and every single change on my GTR. every 3-5000kms. the 10w-60 is designed for high stress engines. wouldnt you agree that a GTR is a stressful piece of equipment.. therefore since i like pushing my GTR to 9000rpm (katimoto chipped ecu) i think ill use the formula R.

I actually put the formular R EDGE in on sunday and immediately i noticed that it became smooth and quieter again like a tammed lion. maybe its my mind talking but i think the edge is improved it does say so on the bottle. I think ill always use the 10w-60 it only costs me $55 a bottle. and i give my GTR more throttle than brakes. I highly recommend it.

Keep in mind a good oil filter is needed too. DONT USE VALVOLINE. im using a RYCO filter which cost $11 at repco (DICKHEADS). ill be using genuine Nissan Filters next time.

hope that helps u sway ur mind. BTW its not too thick IMO

Mark.

I cant begin to tell you how good the formular R range is. used the 10w-60 on my GTiR and every single change on my GTR. every 3-5000kms. the 10w-60 is designed for high stress engines. wouldnt you agree that a GTR is a stressful piece of equipment.. therefore since i like pushing my GTR to 9000rpm (katimoto chipped ecu) i think ill use the formula R.

I actually put the formular R EDGE in on sunday and immediately i noticed that it became smooth and quieter again like a tammed lion. maybe its my mind talking but i think the edge is improved it does say so on the bottle. I think ill always use the 10w-60 it only costs me $55 a bottle. and i give my GTR more throttle than brakes. I highly recommend it.

Keep in mind a good oil filter is needed too. DONT USE VALVOLINE. im using a RYCO filter which cost $11 at repco (DICKHEADS). ill be using genuine Nissan Filters next time.

hope that helps u sway ur mind. BTW its not too thick IMO

Mark.

Nissan oil filter cost me just tad over 9 bucks at dealer.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Latest Posts

    • Yeah, that's fine**. But the numbers you came up with are just wrong. Try it for yourself. Put in any voltage from the possible range and see what result you get. You get nonsense. ** When I say "fine", I mean, it's still shit. The very simple linear formula (slope & intercept) is shit for a sensor with a non-linear response. This is the curve, from your data above. Look at the CURVE! It's only really linear between about 30 and 90 °C. And if you used only that range to define a curve, it would be great. But you would go more and more wrong as you went to higher temps. And that is why the slope & intercept found when you use 50 and 150 as the end points is so bad halfway between those points. The real curve is a long way below the linear curve which just zips straight between the end points, like this one. You could probably use the same slope and a lower intercept, to move that straight line down, and spread the error out. But you would 5-10°C off in a lot of places. You'd need to say what temperature range you really wanted to be most right - say, 100 to 130, and plop the line closest to teh real curve in that region, which would make it quite wrong down at the lower temperatures. Let me just say that HPTuners are not being realistic in only allowing for a simple linear curve. 
    • I feel I should re-iterate. The above picture is the only option available in the software and the blurb from HP Tuners I quoted earlier is the only way to add data to it and that's the description they offer as to how to figure it out. The only fields available is the blank box after (Input/ ) and the box right before = Output. Those are the only numbers that can be entered.
    • No, your formula is arse backwards. Mine is totally different to yours, and is the one I said was bang on at 50 and 150. I'll put your data into Excel (actually it already is, chart it and fit a linear fit to it, aiming to make it evenly wrong across the whole span. But not now. Other things to do first.
    • God damnit. The only option I actually have in the software is the one that is screenshotted. I am glad that I at least got it right... for those two points. Would it actually change anything if I chose/used 80C and 120C as the two points instead? My brain wants to imagine the formula put into HPtuners would be the same equation, otherwise none of this makes sense to me, unless: 1) The formula you put into VCM Scanner/HPTuners is always linear 2) The two points/input pairs are only arbitrary to choose (as the documentation implies) IF the actual scaling of the sensor is linear. then 3) If the scaling is not linear, the two points you choose matter a great deal, because the formula will draw a line between those two points only.
    • Nah, that is hella wrong. If I do a simple linear between 150°C (0.407v) and 50°C (2.98v) I get the formula Temperature = -38.8651*voltage + 165.8181 It is perfectly correct at 50 and 150, but it is as much as 20° out in the region of 110°C, because the actual data is significantly non-linear there. It is no more than 4° out down at the lowest temperatures, but is is seriously shit almost everywhere. I cannot believe that the instruction is to do a 2 point linear fit. I would say the method I used previously would have to be better.
×
×
  • Create New...