Jump to content
SAU Community

Recommended Posts

Hi Alex,

I'm no expert when it comes to oil but some peoples ideas on this forum (not this thread) can be totally wrong. Remembering oil is a very complex item and in terms of lubrication, there are many tradeoffs from start up lubrication to hot lubrication, and the amount of heat the oil transfers around the car.

In reply to your question Alex the 10w-60 seems ok for Canberra all year round. The manual (for my car and I believe yours) says 7.5-35w oil. So a 5 or 10 weight oil when cold should be fine. The higher number (hot) can generally be as high as you want, if you are racing the 60w is when most people recommend as the oil gets very hot and as you probably know oil thins out the hotter it gets, daily driving 40 is fine as the oil never reaches really high temperatures.

I've been running Shell 5-40w but I will be using the Castrol 10-60w in Summer or for any track days.

I've never changed oil on an RB25 but it can't be as hard as the RB26. Just don't rev the engine to get the last bits of oil out :-)

Link to comment
https://www.sau.com.au/forums/topic/220214-what-oil/#findComment-3884876
Share on other sites

Hi Alex,

I'm no expert when it comes to oil but some peoples ideas on this forum (not this thread) can be totally wrong. Remembering oil is a very complex item and in terms of lubrication, there are many tradeoffs from start up lubrication to hot lubrication, and the amount of heat the oil transfers around the car.

In reply to your question Alex the 10w-60 seems ok for Canberra all year round. The manual (for my car and I believe yours) says 7.5-35w oil. So a 5 or 10 weight oil when cold should be fine. The higher number (hot) can generally be as high as you want, if you are racing the 60w is when most people recommend as the oil gets very hot and as you probably know oil thins out the hotter it gets, daily driving 40 is fine as the oil never reaches really high temperatures.

I've been running Shell 5-40w but I will be using the Castrol 10-60w in Summer or for any track days.

I've never changed oil on an RB25 but it can't be as hard as the RB26. Just don't rev the engine to get the last bits of oil out :-)

an important thing to note, is that while you are definitely correct in using thicker oils in racing, for daily driven purposes using too thick of an oil can be detrimental in the worst cases. certainly with cars like skylines, people want to rev the engine occasionally, however the cars may only be used for 30-40 minutes at a time. if i recall properly the best viscosity for protection at high revs is between 10-15 centistokes. for a 10w-60 oil to reach 15cs it needs to be over 120 degrees C, while 10w40 needs to be over 100degrees C. 10w40 only starts to become too thin over 120degrees.

the problem is at 90 degrees C, 10w60 oil is still 30cs and too thick for revving an engine. high engine speed and high viscosity can lead to foaming and worst of all cavitation

im not an oil expert either, im just saying its important to identify what purpose your oil needs to fulfill, racing protection or daily longevity. for my next oil change ill probably get a synthetic like 5w-40 or 0w40 as the viscosity offers more protection when the car is first started at low temperature. your current shell 5w-40 sounds like a good bet for daily use, perhaps its a good idea to put in thicker oil specifically for a track day, but run the thinner oil when you go back to daily use

Link to comment
https://www.sau.com.au/forums/topic/220214-what-oil/#findComment-3885794
Share on other sites

an important thing to note, is that while you are definitely correct in using thicker oils in racing, for daily driven purposes using too thick of an oil can be detrimental in the worst cases. certainly with cars like skylines, people want to rev the engine occasionally, however the cars may only be used for 30-40 minutes at a time. if i recall properly the best viscosity for protection at high revs is between 10-15 centistokes. for a 10w-60 oil to reach 15cs it needs to be over 120 degrees C, while 10w40 needs to be over 100degrees C. 10w40 only starts to become too thin over 120degrees.

the problem is at 90 degrees C, 10w60 oil is still 30cs and too thick for revving an engine. high engine speed and high viscosity can lead to foaming and worst of all cavitation

im not an oil expert either, im just saying its important to identify what purpose your oil needs to fulfill, racing protection or daily longevity. for my next oil change ill probably get a synthetic like 5w-40 or 0w40 as the viscosity offers more protection when the car is first started at low temperature. your current shell 5w-40 sounds like a good bet for daily use, perhaps its a good idea to put in thicker oil specifically for a track day, but run the thinner oil when you go back to daily use

Hey Zoomzoom sounds like he knows what he's talking about. We had to find someone who could put some science behind it.

Just remember get the oil that is classed as a fully synthetic oil and also remember that different oils of the same rated viscosity can react differently.

I remember a certain mechanic telling me the 5-40 weight oil was too light for the GTR when cold (the 5) and that was why I was having a leakage issue.

Link to comment
https://www.sau.com.au/forums/topic/220214-what-oil/#findComment-3887759
Share on other sites

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


  • Similar Content

  • Latest Posts

    • Time to decide what’s more import, your power level or your budget because you’re going to struggle to keep both 
    • Our Southern Highlands Cruise is proudly registered with “R U OK?” Day.  Sometimes the best way to check in on your mates is by getting out for a drive together. Sharing a common passion like cars creates the perfect space to chat, connect, and support each other.  A simple “R U OK?” can make all the difference. Let's enjoy the drive, the company, and look out for one another. PLEASE WEAR YELLOW FOR “R U OK?” DAY Sunday 14th September 2025 9:30AM Meeting Crossroads Homemaker Centre 10:00AM Cruise Departure Via Old Hume Hwy 11:45AM Arrival at Mittagong RSL Club Meet Location: Crossroads Homemaker Centre Final Destination: Mittagong RSL Club *Disclaimer* There will be a lead and follow car so no one should get lost. If you would like to attend or bring others along please put your name down and a +1 as numbers will be needed prior! This is NOT a race and we will all be adhering to all road rules. If this is what you want please come to one of our many track days. This is an official SAU:NSW event and will be run under a CAMS permit. One of the things that really sets our club apart is our commitment to being true enthusiasts. When on normal roads we strive to maintain good relations with the authorities as well as the public in general. When attending one of Skylines Australia NSW events please try to: • Be aware of surrounding environment and act accordingly. • Drive courteously on the state’s roads as a true enthusiast should. • Understand how important it is to maintain the good name of SAU NSW and thus, treat others accordingly. • Any misbehavior will not be tolerated and you will be asked to leave.
    • Yep, its been down for a while, as I understand it it will be back soon.
    • Yeah I also looked at Plazmaman, but, it ended up alot  cheaper getting black ones through EFI when you also added in the delivery cost
    • Nice shot! They look super clean. The roof rack delete on the black one is interesting. Would like to see more pictures from different angles. It's subtle but could make quite a difference to how the car looks in profile.
×
×
  • Create New...