What Oil Viscosity To Use?

[re34perGTT]

Hi all,

I own an r34 gtt and am looking for an oil to use to suit daily driving and the odd track day. I live in Perth so it doesn't get that cold over here as well. If anyone could recommend what combination would be best ie 10w-50, 5w-40 etc it would be greatly appreciated !

Attached is some oils Supercheap sell. Any recommendations on what one to buy would also be great

Thanks in advance

[re34perGTT]

Also before anyone says search the forums I've seen lots of stuff on what brand of oil people use but not too much on the viscosity, but if someone finds a forum discussing this my apologies and could you please link me !

[KiwiRS4T]

If you go to the track at all a full synthetic gives you a measure of extra protection.

There are lots of opinions about viscosity but I use Motul 300V 15W 40

If you have an oil pressure gauge and preferably an oil temp gauge as well you can see what works for you.

[Ryno]

For years I've persisted with using 10W-40 weight oil as I believe that's what's recommend. Using that weight I've always experienced a slight amount of oil misting out through the front of the engine (cam shaft seals etc). Several seal changes over the years and different cam breather setups never fixed the issue.

I recently changed to 15W-50 weight fully synthetic and the leaks appear to be gone.

[Missileman]

Nice Zinc content and not too expensive, my motor is low Ks so oil consumption is close to zero...http://www.penriteoil.com.au/products.php?id_categ=1&id_fuel_type=3&id_products=7

[niZmO_Man]

Why not have all the combinations?

Penrite Premium 5 (5W-60)

[scotty nm35]

In b4 'you need gearbox weight oil.'

Damn, too late...

[Joshbigt62r]

I run Castrol 10w-60 and have done for years. Many of the top nane tuners/mechanics performance shoos recommend this oil also.

[re34perGTT]

Thanks for all the suggestions! What oil on the pic I sent should I buy ?

[GTSBoy]

Given the usage model of your car you could realistically use just about any of those oils.

Given that Perth gets pretty hot and that you plan to do some track work and that it IS a turbo, avoid anything with a 30 rating. You need at least 40. If you tend to run the oil to high temperatures (do you even know how hot your oil gets?) then a 50 would be better.

Out of all that lot in the Supercrap listing, I would lean towards the Penrite 10 10ths or HPR10.

[niZmO_Man]

Thanks for all the suggestions! What oil on the pic I sent should I buy ?

Penrite Racing 10. Change it every 10k km with oil filter.

[Chris32]

Been using Penrite Racing 10 for 8 oil changes so far and I can't fault it.

My car runs an external oil cooler, so the oil temp is at 80° for most of the time.

Highest I've seen it get to is 100° after some prolonged spirited driving, but it gets down to 80° pretty quickly and oil pressure is stable from when it first goes in to when I change it at 5000kms. Ive been tempted to go longer between changes but its not overly expensive

Have used Motul, Mobil 1 in the past and the car feels happier. Tempted to try the Nulon synthetic at some stage also

[MrStabby]

I reckon ?W-40 is the best choice. AFAIK the only two valid reasons to go thicker are;

1. To bring oil pressure up to spec in a worn motor

2. To hack around running your oil too hot.

Instead of #2, get an oil cooler that will keep your oil below 120 Deg, and use a full synth 40.

[GTSBoy]

^ per what he said, even going up to a 50 or 60 hot grade oil only buys you a TINY bit more oil viscosity once temperatures are up to 100°C or more. You are far better off getting oil temperature under control than bandaiding it with "thicker" oil.

[AngryRB]

my pick is mobil 0-40w fully synthetic with a bottle of Zddp additive,

[re34perGTT]

Yeah I know but I have <2 weeks to do all this stuff to my car for the track day and adding an oil cooler isn't an option right now, but when I get the time I definitely will. And thanks for the suggestions guys. I was looking at the penrite 10w-50 oil before and I think I'll go with it for now until I get an oil cooler, then maybe I'll go for a 10w-40 oil or stick with the penrite depending on how it goes. Once again much appreciation for all the continuous help here !

[Sinista32]

Penrite Everyday 10w -40

[niZmO_Man]

R32 GT-R, 160k+ km (probably more), no oil cooler, two overheats with 5W-60 (like 130+°C oil temps), three track days. Motor sounds the same as it's always been, car runs fine .

Ran a track day with Racing 10 as well, I think it runs better with that, but my car runs hot on the track.

Now that I have an oil cooler, I might switch back to Racing 10.

[Roy]

Each to their own I guess but if its a street car that is only doing the occasional track day then frankly as long as its a reasonable quality semi synth oil can you really drive a car that hard on the road that a 10W-40 or 15W-50 or thereabouts is going to be an issue?

When you do a track day, the 1-2 times a year ALWAYS put a fresh filter and sump of oil in the car. That't my practice. And frankly people saying run a cooler, keep it under 100deg....my experience is your oil temp will run over 100, more like 110-120deg c which is perfectly fine.

Remember that the oil going through/around the cams and lifters is subject to far less shear and temp and only running at half the speed of the crank vsgoing through the mains and big end so you are only measuring the average oil temp on your gauge.

The old wives tail , which seems to hold true on race cars is run the oil over 100deg c so any moisture/condensation, blow by gases etc dont stay entrained. How true that is I dont know...but of course those engines are purpose built and toleranced accordingly

So that is the BS I tell myself and every time I go to the track I always run a genuine Nissan oil filter and Castrol 10W60. I love the viscosity, rape my engine with boost and revs and havent lost a bottom end.

If you find on your aftermarket pressure guage you have 60psi at 7,000rpm with the oil up to temp with XX oil then I would be bumping up viscosity so that you are between 70-80psi

[re34perGTT]

Cheers mate, great advice ! Well I just got a service and put in the new oil and new filter and track days next week so I should be fine but for the next one I'll definitely do that