Please can someone advise on what enfine and gearbox oil to use for my 1993 t/t. I use it for short journey to work and weekends for kicking my mates supras ass ha ha . I am bit confused as so many advices on what one to use . am i right in thinking 15-50 is right fully synthetic?? and what about gearbox and diff.

 

Also how easy it to change rear diff oil and front diff oil ( or is it part of engine??) and the gearbox oil ?? Also where can i go to get amounts to put in.

 

Help !!! :mac1:

Hi mate

 

Engine oil choice always causes great debate here :p

 

Personally, if the engine is in good shape, reasonable mileage and not heavily modded then a 5w40 fully synth is fine. If the engine is modded then a 5w50 would be better.

 

15w is too thick for winter use IMO.

 

See stickey thread from Oilman - he is also the guy to purchase from at reasonable prices.

 

Don't know about gear oil....

 

Richard :cool:

Best one we've experienced is AMSOIL 75w-90...runs perfect for all weather types and is widely used in a lot of Z32s in the US.

Winter and short journeys point to a 0W40. Mine is approaching 140k miles and I've always put in RS 0-40 Castrol summer and winter. I'd rather have lub getting round fast when stone cold than worry about track days in mid summer. Original tubs too.

 

Sure some will say get thick stuff to dull the rattles on a worn engine or on a very highly stressed engine but I would suggest it'll only wear faster while it waits on treacley oil to get round on a cold morning and while they are waiting the turbo shafts could run dry and run the seals too. Anyway when is a zed engine ever stressed under "normal" driving!

Winter and short journeys point to a 0W40. Mine is approaching 140k miles and I've always put in RS 0-40 Castrol summer and winter. I'd rather have lub getting round fast when stone cold than worry about track days in mid summer. Original tubs too.

 

Sure some will say get thick stuff to dull the rattles on a worn engine or on a very highly stressed engine but I would suggest it'll only wear faster while it waits on treacley oil to get round on a cold morning and while they are waiting the turbo shafts could run dry and run the seals too. Anyway when is a zed engine ever stressed under "normal" driving!

 

Wise words, Willie

 

if the engine is in good form it shouldn't rattle anyway. Nissan recommend 10w40, so a 5w40 or 0w40 would offer the same protection when hot but be better than the 10w40 from cold.

 

I don't like the Mobil 1 0w40 though, that always seemed thinner when I used it in my Mk3 Soop. But RS 0w40 gave no probs :confused:

 

Richard :)

I would look at the following grades:

 

Engine

 

5w-40, 10w-40 or 10w-50 (0w and 15w are not ideal) Fully Synthetic

 

Gearbox

 

80w-90 is specified but I would use a better oil like Fully Synthetic 75w-90

 

If you want to put the best in then ensure they are ester based oils (see my thread and the reasons why) and you can find the Silkolene or Motul range on my website.

 

You can always email me for a price list.

 

Cheers

Simon

you do not need a fully synthetic for these cars a semi is fine (engine oil) , most people on the board use Castrol RS 10/60 failing that Leigh in the traders section (Japcity) does a very good range in millers oils 10/40 10/60 at good prices , If leigh does not have any in stock I have a far bit as I use it for all the cars that come in the garage.

 

Ryan

I use castrol magnatec.

Millers 10/60 which is a for the Engine is a fully synthetic competition oil.

This is what I used in my 300ZX, and my Skyline.

 

The oil comes in 5 litres and retails at £38, but I can do deals if bought in boxes of 4.

 

Millers have a whole range I also use their CRX fully synthetic gearbox oil, and CRX LS for the Limited Slip Diff.

 

If your interested contact me on 01628 669660 or 07717 453532.

Or if you prefer email me on info@japcityltd.co.uk

 

Leigh.

As I've said before, you don't need a 10w-60 and don't be fooled into believing that you need sae 60 due to high temps.

 

A decent Fully synthetic 5w-40, 10w-40 or 10w-50 will do just fine as it will handle temps of up to 130 degC which is more than adequate.

 

Thinner oils will give better cold start, better BHP and better fuel economy so if your engine is in good nick, there is no reason not to use them.

 

Perhaps I can remind you of this post:

 

Surely the thicker the oil the better!

 

This isn't always true - even when using a petroleum oil.

 

Although it is true that heavier viscosity oils (which are generally thought of as being thicker) will hold up better under heavy loads and high temperatures, this doesn't necessarily make them a better choice for all applications.

 

On many newer vehicles only 0w-40, 5w40 or 10w40 engine oils are recommended by the manufacturer. If you choose to use a higher viscosity oil than what is recommended, at the very least you are likely to reduce performance of the engine. Fuel economy will likely go down and engine performance will drop.

 

In the winter months it is highly recommended that you not use a heavier grade oil than what is recommended by the manufacturer. In cold start conditions you could very well be causing more engine wear than when using a lighter viscosity oil.

 

In the summer months, going to a heavier grade is less of an issue, but there are still some things to be aware of.

 

Moving one grade up from the recommended viscosity is not likely to cause any problems (say from a 10w40 to a 10w50 oil). The differences in pumping and flow resitance will be slight. Although, efficiency of the engine will decrease, the oil will likely still flow adequately through the engine to maintain proper protection. However, it will not likely protect any better than the lighter weight oil recommended by the manufacturer.

 

Moving two grades up from the recommended viscosity (say 10w40 to 10w-60) is a little more extreme and could cause long term engine damage if not short term. Although the oil will still probably flow ok through the engine, it is a heavier visocosity oil. As such it will be more difficult to pump the oil through the engine.

 

More friction will be present than with a lighter viscosity oil. More friction means more heat. In other words, by going to a thicker oil in the summer months, you may actually be causing more heat build-up within the engine. You'll still be providing adequate protection from metal to metal contact in the engine by going with a high viscosity, but the higher viscosity will raise engine temperatures.

 

In the short run, this is no big deal. However, over the long term, when engine components are run at higher temperatures, they WILL wear out more quickly. As such, if you intend on keeping the vehicle for awhile, keep this in mind if you're considering using a heavier weight oil than the manufacturer recommends.

The best advice is to is to stay away from viscosity grades that are not mentioned in your owner's manual.

 

The book recommends 10w-40 so stay around this viscosity unless you are using the car for competition in which case a 10w-50 may be warranted. If you are doing a lot of cold starts and short trips, a 5w-40 may be warranted.

 

Look at the tech specs for Motul 300 range and Silkolene PRO range here. These are proper synthetic oils that will give the best protection.

 

http://www.opieoils.co.uk/lubricants.htm

 

Cheers

Simon

A slight error in your post above.

 

A 10/60 is not a thicker oil.

 

The 10 is the viscosity at cold, and hence a 10/30, 10/40 or 10/60 are all the same at cold. However a 10/60 will hold on to its elasticity to a much higher temperature, and hence its much more sutitable to the stresses and strains a Turbo engine will put it under.

 

A 10/60 oil in a rally car at the end of a stage can drop to the viscosity of a 10/30 but due to the elasticity not being breached will return to its 10/60 visoscity once cooled down again. However a 10/40 or 10/30 would of breached its point of elasticity, and the oil would have lost its elastic properties. Hence degradation and the need to change the oil more frequently.

 

This is why many tuners are now of Skylines, 300ZX and Supra's are now using a 10/60 synthetic oil.

 

Leigh.

 

To find out more details:- http://www.millersoils.net/index2.html

Leigh.

 

I was referring to the viscosity when hot not cold.

 

I would also like to point out that some well known 10w-60's are not synthetics, they are in fact hydrocracked petroleum oils and due to the wide viscosity range require buckets of VI Improver to prop them up. This makes them more not less prone to shearing with use. So unless the oil has shear stable basestocks (pao/ester) within a couple of thousand miles it will be a 10w-30 or 10w-40 whereas a proper synthetic oil will be far more thermally stable for a far longer period.

 

Finally, modern engines rarely require sae 60 when hot when thinner true synthetic oils are more than capable of handling extremely high temperatures and give better power deliver and fuel consumption.

 

Perhaps people here should read this:

 

If you are "modding" your car and adding BHP then consider your oil choice carefully as the stock manufacturers recommended oil will not give you the protection that your engine requires.

 

A standard oil will not be thermally stable enough to cope with higher temperatures without "shearing" meaning that the oil will not give the same protection after a couple of thousand miles as it it when it was new.

 

Let’s start with the fundamentals. An engine is a device for converting fuel into motive power. Car enthusiasts get so deep into the details they lose sight of this!

 

To get more power, an engine must be modified such that it converts more fuel per minute into power than it did in standard form. To produce 6.6 million foot-pounds per minute of power (ie 200 BHP) a modern engine will burn about 0.5 litres of fuel per minute.(Equivalent to 18mpg at 120mph). So, to increase this output to 300BHP or 9.9 million foot-pounds per minute it must be modified to burn (in theory) 0.75 litres.

However, fuel efficiency often goes out of the window when power is the only consideration, so the true fuel burn will be rather more than 0.75 litres/min.

 

That’s the fundamental point, here’s the fundamental problem:

 

Less than 30% of the fuel (assuming it’s petrol) is converted to all those foot-pounds. The rest is thrown away as waste heat. True, most of it goes down the exhaust, but over 10% has to be eliminated from the engine internals, and the first line of defence is the oil.

 

More power means a bigger heat elimination problem. Every component runs hotter; For instance, piston crowns and rings will be running at 280-300C instead of a more normal 240-260C, so it is essential that the oil films on cylinder walls provide an efficient heat path to the block casting, and finally to the coolant.

 

Any breakdown or carbonisation of the oil will restrict the heat transfer area, leading to serious overheating.

 

A modern synthetic lubricant based on true temperature-resistant synthetics is essential for long-term reliability. At 250C+, a mineral or hydrocracked mineral oil, particularly a 5W/X or 10W/X grade, is surprisingly volatile, and an oil film around this temperature will be severely depleted by evaporation loss.

 

Back in the 1970s the solution was to use a thick oil, typically 20W/50; in the late 1980s even 10W/60 grades were used. But in modern very high RPM engines with efficient high-delivery oil pumps thick oils waste power, and impede heat transfer in some situations.

 

A light viscosity good synthetic formulated for severe competition use is the logical and intelligent choice for the 21st century.

 

Hope this explains what I'm talking about.

 

Cheers

Simon

 

PS. Do you work for Millers Oils then?

Simon,just to put you in the picture regarding Silkolene,a member on here bought some off you and ended up pouring it in the bin as his Z32 did not like it,he went back to using Castrol RS and the car feels much better so he said.

Mac, I agree that the Silkolene is crap too, I had it in my Z and IMHO it is way way too thin for a Z ??? I am sure that after driving my car quite fast for a day that it had something to do with a tapping/rattling coming from my bearings/Hydraulic lifters. If you speak to Baggins (Z TECH) on this one he will probably tell you the same as in the Silkolene is way too thin, it's like P155.....

Well, can't argue with that but I find it unbelievable. He never spoke to me about it and I would certainly like to hear the reasons why he didn't get on with it.

 

Cheers

Simon

What grade is too thin? There are several and some are very heavy viscosities.

 

Regarding tappets perhaps you should read this!

 

http://www.lancerregister.com/showthread.php?s=&threadid=59020&highlight=silkolene

 

Cheers

Simon

Hi Simon,

 

No I don't work for Millers but I do sell it.

 

I only sell products I would put in my own car, and spend lots of time researching and then trying the product myself.

 

I back this up with reports of useage in Motorsport scenarios.

 

The Millers oil I sell is all competition grade oils.

They all start CFS for Competition Fully Synthetic, and come in 10/30, 10/40, 10/60, and for Endurance racing 15/50 grades.

 

From experience and backup support the 10/60 is best for the 300ZX.

Its also the oil recommended by well known tuners for the Skyline.

 

Leigh.

In case anyone is interested, Costco do Mobile One 10/40 4 litres for £23.00 inc vat

Firstly in answer to your question Karl, only use a good quality brand name synthetic oil!

 

If you are in Dire financial straights then you can get away with a semi for a while!

 

I heard the same story about someone pouring silkolene out and it being like water when it was cold, I have heard this is a good thing though as it will reach parts of the engine on start up faster than a thick oil.

Dont want to cause a war but im using castrol rs 10/60 and am about to put a slightly thinner oil in for winter, i have the choice of either castrol rs 0/40, or valvoline fully synth 5/50.

 

Which is best and why???

Why would you change to a thinner oil for the winter???

 

We don't live in Siberia, a 10/60 is good down to -20 degrees C. This means that it properties at startup from cold are no different down to this temperature.

This is the same for all oils starting with 10, see the attachment oil chart.

 

Now all you would be doing by changing to a thinner oil, is reduce your higher temperature protection, because the viscosity of the oil would not be as good.

 

Leigh.

Please can someone advise on what enfine and gearbox oil to use for my 1993 t/t. I use it for short journey to work and weekends for kicking my mates supras ass ha ha . I am bit confused as so many advices on what one to use . am i right in thinking 15-50 is right fully synthetic?? and what about gearbox and diff.

 

Also how easy it to change rear diff oil and front diff oil ( or is it part of engine??) and the gearbox oil ?? Also where can i go to get amounts to put in.

 

Help !!! :mac1:

 

LOL!! oh yeah, this was the origional question! ;)

 

engine oil, as Baggins said elswhere in this thread, A good quality Semi Synthetic is fine. until recently i used Mobil Super S 10W40. as most of us here change our oils far too frequently (i do mine every 3000 miles) & wont benefit from the cost of a fully synth over semi.

I now use a fully synth 5W40 (Mobil Synt S) only cos thats what i stock at work now & its free! :D

 

rear diff & gearbox oil is easy to change, but follow the manual as you need to short a temp sensor out on the diff to prime the pump to the oil cooler.

 

& there is no front diff - these arnt 4WD you know ;)

Well, can't argue with that but I find it unbelievable. He never spoke to me about it and I would certainly like to hear the reasons why he didn't get on with it.

 

Cheers

Simon

I don't doubt that silkolene is a good oil used in the right circumstance and I don't doubt that you know your stuff oilman but having used silkolene i can only come to one conclusion and that is I would certainly not put it in my car ever again let alone any of my customers , as someone has pointed out, this oil for what ever reason is like water when going in cold even thinner when hot , I appreciate that you may gain approx 1 bhp by using a thinner oil but at what cost, I have tried many oils over the last few years including Mobile etc which again tbh I would not use, I use and recommend both Castrol and Millers for a reason they work without any problems.

 

 

Ryan

How does it get thinner when hot, I thought oil thickens when hot and with the 50 weight it is over spec in thickness for our engines!

How does it get thinner when hot, I thought oil thickens when hot and with the 50 weight it is over spec in thickness for our engines!

Mark thats my point :confused:

So Ryan you are saying that silkolene 10-50 gets thinner when hot, than other 50 weight oils?