A.Moore

As the title says.I've done a fair bit of researching before i changed my oil,eventually deciding on Mobil 1 0W/40 spec.Please please don't anyone say it's too thin!!

What do you use and why?

rb5371

iTrader: (4)

i changed mine the other day used the same as you 0w/40 but castrol rs i used to use rs 10w/60 in my subaru's and nether had a problem with either and one had done 100000m.

Azrael

Castrol TWS Motorsport 10W60

only others I would use are Motul 300V Competition and Valvoline VR1 Racing


I wouldn't use less then 5W50 oil at no circumstances. Turbocharged engine needs oil very resistant to heat....

Steve Escos

iTrader: (18)

Castrol rs 10/60 used it in my other cossies as well.

A.Moore

Hmmmmm.................as an example i'm lead to believe that the

0w is the cold flow viscosity of the oil and the 40 is the viscosity value at normal running temp, so a 10W/60 would be a thicker oil at normal running temp.
I've heard that 60 grade oils are too thick at running temps????

The main concern is regular oil changes, for me 3K as i'm running stage 3 tune, fuel can contaminate your oil over time and begin to breakdown the oil lessening it's properties.
Mobil 1, like many other oils are able to operate under extreme conditions of heat, retaining it's protective properties.

K3V HA

Its too thin!!!

Al, i spoke to a certain Mr Hadland when i first got my ERST, he said that he uses 10/60 castrol in his cossies, and that it would be fine for a ERST too. I trust him And Steve got mesome on agreat deal!!

Azrael

Viscosity of oils at different temperatures is very complex matter. 0W oil is in fact oil that is identical to 5W oil but has some other parametrs changed - don't remember that part on oils. Second number is more important. First is important for cold starts but all performance car here run 10W60 oils with no problems in winter.


>I've heard that 60 grade oils are too thick at running temps????

The only oil I hear problems with cold start is Motul 300V LeMans - especcially new one which is 20W60 and competition only in our climate. But in normal situations you can use anything else.


3k miles seams a little bit over exagerated but I don't know. I change it around 7k - kilometers.

I don't like Mobil products - lts of VERY BAD experience with it but here many oils are just falsified, including Castrol RS that's why I'm using TWS Motorsport which is about 1/3 more expensive.

A.Moore

I'll not disagree with anything you or Kev has said.It's a very complex subject, so you have to make your own decisions.I've made mine, so it's Mobil 1 0w/40 for me!!Just wondering what others use as oils have come a long long way since the Escort Cosworth was launched.

Azrael

Remeber that what was availible when YB engines were developed didn't have to be what schould be good for the engine. I mean they surely had many warranty claims with turbochargers runing the car on Motorcraft Formula S....

dave green

I use castrol RS 10/60, when i first got my cossie over four years ago i use a 5/40 fully synthetic but when driven hard the oil pressure was very poor, changed to castrol 10/60 and it made a massive differance.


Dave

Turbo Chris

Yes Castrol RS 10/60 for me aswell

Been good upto now

Chris.

A.Moore

Dave oil pressure when hot on tick over is not a concern, as long as it shoots up when throttle is applied.An oil hot with a 40 rating may well show a lower pressure on tickover than the 60 grade oil, but it doesn't mean there is less protection, it just means the oil is thinner hence the reading.Thinner oil moves better through the engine imo as long as the quality is there!

Azrael

Main bearings need oil cushion on tickover also. Mine after really hard rally-stage at 30 degrees celsius outside temperature had very poor oil pressure on normal Castrol RS (less resisstant to heat then TWS even tough 10W60 too) what wuld be with something like SLX 0W30? No pressure? That kills the bearings. I never had any problems with oil pressure while throttle applied.

art411y

iTrader: (1)

defo castrol 10 60 i used 0 40 for 2yrs .i think 0 40 for a car with less than 10k on the clock it would be fine .but then a zetec is unhappy with more than a o 30 .volks wagen aiso state o 30 for their new cars .bugger dont know really

Chris Reade

I seem to be the odd one out, I use Shell Helix.

Glenn5

mobil 1 15 50 everytime 2tho miles as it spends alot of time parked up recommended by pj motorsport they use it in fresh builds too.

A.Moore

Ok, so where does your oil pressures 'sit' on idle after a rag?

art411y

iTrader: (1)

thats the only difference i spotted when i changed from mobil to castrol in the heat of summer stuck in traffic or after a long hard run home from a show the oil pressure was up considerably,with mobil it did at times flick in the red but with castrol its nowhere near

Skiman

I just use that ford fully synthetic stuff...

A.Moore

With Mobil 1 after a rag in mine the needle can be a few mil above the red,as throttle is applied it's straight back up.It isn't just a case that 10w/60 protects better just because you have higher oil pressure at idle.

Azrael

It's Mobil 1

Holty

Mines onm mobil 1 and it sit just in box section when idling at running temp.

How much do yours use between max and min in miles.

Mine seems to need topping up every 300 to 400 miles it goes right to min in about this period of time.

Azrael

Mine is the same but kilometers :-( But I have rear crankshaft seal failure - will check how is when I fix that...

A.Moore

Mine does require a bit of topping up from time to time but i am a low mileage user, so don't really notice.All cossies need the oil checking regulary, i keep mine on 'full' all the time, very important.

Azrael

Full isn't the best option as far as I know - half way is better. On hard righ corners some may leak through breather system when full, or so I was told by rally people over here.

Holty

Think i'll switch my oil to castrol 10/60 and see how it gets on.

A.Moore

Can you post back and let us know how you get on?

Holty

will do chap!!!

wighthot

I use Castrol RS 10-60W, it's ideal for day to day use and the occasional track use.
It gets changed every 2500miles, and is still as clean as when it went in

oilman

Oh no not again

Believe me you don't need sae 60 either

Said it a thousand times, too thick and harder to pump round the engine.

Don't worry, I don't listen either

A good 5w-40, 10w-40 or 10w-50 is all you need depending on application.

Interesting thread though

Cheers
Simon

oilman

So if a tuned cossie engine can't run on a thin oil, how come this one does?

Names witheld at request:

From: xxxx
Sent: 07 May 2004 16:16
To: Rowland, John

John,

Just a note to let you know I've heard from xxxxx - the rally driver with
the 300+bhp Peugeot-ice-racer-bodied hybrid with the normally asthmatic
Cosworth in the back.

Prior to you taking over, he used to have to strip the engine after every event
(normally 45 miles, he couldn't get it to last for a National event of 70-80
miles) and change the big end bearings every time.

He'd been everywhere and tried everything (including Halfords!), and couldn't solve his problem.

First off, he was really surprised when you asked to look at the bearings, as
no-one had ever asked! He was equally surprised by your recommendation to go
thinner, and also, I have to say, worried.

He equated 'thickness' with 'better protection'. I eventually persuaded him to try Pro S 5w/40, as you suggested,

He called me to say he'd stripped the engine this week, after it's FOURTH event
(approx 200 competitive miles!), and there isn't a mark on it. He is utterly
delighted, and asked me to pass on his thanks for all your help and expertise.

I'd also like to add my thanks to you. He is extremely influential in
competition circles, and is now going to tell the world and his wife what, and
who, sorted this problem.

Once again, many thanks
Regards
xxxx

Azrael

Oilman - normally aspirated high revivng engine isn't exactly the same as low revs hight torque turbo-charged engine. Is it?

oilman

No, how come you ask?

Azrael

From what I am told. (I am not an engine or oil expert, just a hobbyst)

1. turbocharged engine oil is subjected to much bigger temperatures - especially in the turbocharger bearings and in the pottom of piston when sprayed there too cool them, this degrades oil much quicker and also can locally lower it's visosity below damaging levels (even though overall oil temperature is held at the reasonable limits due to heat exchangers, oil coolers and so on)

2. The working conditions of the engine pressure lubricated bearings - crank and rod bearings are different when the bearings are subjected to much higher loads in the engine that has big torque per cylinder factor.
In N/A aplication there is less forces but more rotational speed. This gives different needs for lubricants.


I must reapet I by no means am an expert in those matters. But from what I can see generall tendencies are to use 10W60 oils in high output to capcity turbocharged engines and rally teams use those. Castrol RS 10W60 and Motul 300V Competition/ Le Mans series being most popular. IN modern high reving N/A aplications theere are tendencies to use less and less viscosity oils - but I have no idea how much is this due to polution and fuel economy and how due top technical reasons. Only Japaneese tuners tend to use things like 10W30 or 0W30 oils in extreemely high power aplications - I have no idea why.

This is becoming an very interesting technical thrad - maybe some mods could move it to technical forum?

oilman

The point is that quality is all important in a modded or high performance engine and there are great benefits to using thinner oils which is now possible with the emergence of synthetics. Why? Well, I'll leave that to the experts:

Quote: John Rowland (Silkolene Chief R&D Chemist with 40 years experience)

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.

Unquote:

You see thicker was better when all that was available were mineral oils but chemistry and oils have moved on and synthetics have given birth to a breed of tougher lower viscosity oils which are superior lubricants in every area.

Cheers
Simon

Azrael

I cannot dispute that. But quite common experience of competition/hard road use is that e.g. high power turbocharged engines tend to use MUCH more thinner oil. I mean thicker ones usually greatly reduce oil use and that is also in new engines - so it's not engine wear. The other thing is that though I am no big expert th xxWxx numbers tend not to show all the oil capabilities - if you study very carefull producers numbers oils which are the same viscosity e.g. 5W40 can be of completly different actuall viscosities in operating temperatures. As far as I remember firts number is in 0 degrees and the other in 100? I understand then modern synth oils are very stable in high temperatures but there is some point at which their qualities degrade and so I was told (in example by people from Castrol Poland) that as a general rule you can think that this happens to thicker oils in higher temperatures.


If there is no point for such thick oils why eerybody uses them? And why the thickest synth oils are the most expensive and adviced to be used on the ost advanced sports-car engines?

turbinator

5w50 valvoline..

but the normal 10w40 is good enough for almost everything ..

actually no need to use anything else..
but wouldnt use 10w60 ... thickness too high .. can cause lots of failures..

A.Moore

Oilman, thanks very much for your imput, very very interesting.Your views/information seem to equal what i've heard/researched in the past.

Obviously oil is a critical part in the running of an engine and should never be overlooked,especially in high performance engines.I'll stick with my 0W/40 Mobil 1,as my car does lots of 'cold' starts where engines are at most risk to wear.Infact most quality fully synth oils up to a */50 rating seem to be suitable for use.

oilman

Let's clarify a few things.

The "w" (i.e. 10w) number is the cold crank viscosity and the other number (40,50,60) is the sae number which is the oils viscosity at 100 degC.

The relevance of the "w" number is that for example 0w can be used down to -35 degC, 5w down to -30 degC, 10w down to -20 degC so don't get hung up on this one - anything from 15w downwards is fine for the UK climate.

The sae number is more important as this (the higher it goes) generally indicates the oils resistance to heat.

So.......................Now it gets more complicated!

Just because an sae 60 on paper gives higher resistance to heat doesn't mean that it will continue to do so with use. You see all oils "shear" with use (in laymans terms "lose viscosity") and depending on the quality of the oil will dictate the amount of shear or viscosity loss.

So for example a petroleum based 10w-60 which is a wide viscosity oil (0w-30 is a narrow viscosity oil) requires a lot of VI Improvers to make it work, by this I mean that these special polymers are added to make a 10 base oil a 60 when hot.

Here's where the problem occurs, these polymers are prone to shearing with heat and therefore they cause the oil to lose viscosity - With me so far?

So, a 10w-60 will most likely be a 10w-40 within a few thousand miles and losing viscosity all the time giving less protection than a good 10w-50 synthetic oil.

Narrower viscosity synthetic oils like 5w-40, 10w-40 or 10w-50 will provide higher levels of protection for longer as they contain little or none of these polymers to work because they are more thermally stable (capable of coping with higher temperatures) to start with.

So why use viscosity as a tool to combat heat?

Well unless your car is seeing excessive temps (above 130 degC), a good synthetic 5w-40 will cope with 130degC and a 10w-50 140degC plus so there is no need to waste energy pumping a thick oil around the engine which causes friction and heat (in summer further increasing engine temps) and poorer fuel consumption and performance due to oil drag.

To be frank you're better off using a decent sae 40 or 50 and saving the engine the work of pumping something around that is as thick in some cases as an sae 140 gear oil!

Too complicated - sorry but it's difficult to explain

I'm off for a lie down now

Cheers
Simon

A.Moore

Thanks Simon, adding even more to my understanding of engine oils/spec.