Lubricating a modded car, some good advice!

If you are "modding" your Supra 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 or medium viscosity good synthetic formulated for severe competition use is the logical and intelligent choice for the 21st century.

You should seriously consider a "true" synthetic for "shear stability" and the right level of protection.

Petroleum oils tend to have low resistance to “shearing” because petroleum oils are made with light weight basestocks to begin with, they tend to burn off easily in high temperature conditions which causes deposit formation and oil consumption.

As a result of excessive oil burning and susceptibility to shearing (as well as other factors) petroleum oils must be changed more frequently than synthetics.

True synthetic oils (PAO’s and Esters) contain basically no waxy contamination to cause crystallization and oil thickening at cold temperatures. In addition, synthetic basestocks do not thin out very much as temperatures increase. So, pour point depressants are unnecessary and higher viscosity basestock fluids can be used which will still meet the "W" requirements for pumpability.

Hence, little or no VI improver additive would need to be used to meet the sae 30, 40 or 50 classification while still meeting 0W or 5W requirements.

The end result is that very little shearing occurs within true synthetic oils because they are not "propped up" with viscosity index improvers. There simply is no place to shear back to. In fact, this is easy to prove by just comparing synthetic and petroleum oils of the same grade.

Of course, the obvious result is that your oil remains "in grade" for a much longer period of time for better engine protection and longer oil life.

If you would like advice then please feel free to ask.

Cheers

Simon

So what was the good advice? I might have missed it somewhere in the pseudo-scientific and/or history sections

I feel a suggestion of a perfect oil coming on...

And all for only £29.99

Originally posted by Jake

So what was the good advice? I might have missed it somewhere in the pseudo-scientific and/or history sections

Didn't think it was that bad, I've got a lot worse than that.

If I just said that "true" synthetics are best, you would want to know why, at least this explains the difference:)

Cheers

Simon

Nice info!

So, what do you use, are there any clues to the quality/synthetic type etc on the spec letters/ numbers?

Simon works for Opie Oils...he has contacts in the industry. Many clubs are gaining useful insight into what makes a good oil through him, but most arn't so negative as the first 2 in their responses.

But anyway the point is that Ester based oils are a better synthetic than *other* types of synthetic like Castrol RS and Mobil 1.

Hi Simon

Good Post

I must pick your brains about your views on best oil for the rotary engine one day

Didn't mean to sound negative - apologies for any offence.

It was a different first post that threw me! Where was the "Hi, my name's X and I know nothing about Supras' "

Originally posted by Grazer

Didn't mean to sound negative - apologies for any offence.

 

It was a different first post that threw me! Where was the "Hi, my name's X and I know nothing about Supras' "

Fair do's mate...it's always easy to mis-read a mood on a text based conversation.

I'm afraid picking a good oil is difficult due to the labelling of synthetics. The Mobil vs Castrol court gas in the US changed things forever I'm afraid.

I hope this will go some way to explaining why it's a minefield out there and you must be very careful!

Please take time to read this, it's important

Costs of synthetics vary considerably. The most expensive are the “Ester” types originally only used in jet engines. These cost 6 to 10 times more than high quality mineral oils.

The cheapest synthetics are not really synthetic at all, from a chemists point of view. These are in fact specially refined light viscosity mineral oils known as “hydrocracked”. These have some advantages over equivalent mineral oils, particularly in lower viscosity motor oils such as 5w-30 or other oils with a low “W” rating such as 5w-50 etc and they cost about 1.5 times more than good quality mineral fractions.

We use several different grades of this base oil, where appropriate. This is the “synthetic” which is always used in cheap oils that are labelled “synthetic”. Yes it’s a cruel world, you get what you pay for!

Now, you may ask, why are these special mineral oils called “synthetic”? Well, it was all sorted in a legal battle that took place in the USA about ten years ago. Sound reasons (including evidence from a Nobel Prize winning chemist) were disregarded and the final ruling was that certain mineral bases that had undergone extra chemical treatments could be called “synthetic”.

The marketing executives wet their knickers with pure delight! They realised that this meant, and still does, that the critical buzz-word “synthetic” could be printed on a can of cheap oil provided that the contents included a few percent of “hydrocracked” mineral oil, at a cost of quite literally a few pence.

So, the chemistry of “synthetics” is complex and so is the politics!

The economics are very simple. If you like the look of a smart well-marketed can with “synthetic” printed on it, fair enough, it will not cost you a lot; and now you know why this is the case. But, if you drive a high performance car, and you intend to keep it for several years, and maybe do the odd “track day”, then you need a genuine Ester/PAO (Poly Alpha Olefin) synthetic oil, this oil costs more money to buy, because it costs us a lot of money to make, very simply, you always get what you pay for!

This article was written by John Rowland (Chief R&D Chemist of Silkolene/Fuchs) and I have his permission to publish it as his view is that people should be informed before they buy.

Cheers

Simon

Originally posted by DaveRex

Hi Simon

 

Good Post

 

I must pick your brains about your views on best oil for the rotary engine one day

How did you know I have a Rotary?

Cheers

Simon

perhaps my sig should be "if it's not a rota its not a mota"!

All sounds like good info so far, but the ultimate question...

Can you tell us what oils use a genuine Ester/PAO?

Originally posted by Matt Harwood

All sounds like good info so far, but the ultimate question...

 

Can you tell us what oils use a genuine Ester/PAO?

Here here. You say that aero jet engines use fully "proper" synthetic oils. So would my castrol mil designation general gas turbine oil OX26 have been any good an oil to whack in my supra?

Originally posted by DaveRex

Hi Simon

 

Good Post

 

I must pick your brains about your views on best oil for the rotary engine one day

My *opinion* and it is JUST a opinion, is a modern two stroke synthetic in the fuel for tip lubrication, and ash free combustion, and any decent 4 stroke synthetic for the sump, whose hardest jib will be lubing the (mad hot) turbo. I feel trying to make a single oil work in what is effectively a combustion, 2 stroke like environment, and lube the turbos properly is better served by splitting the roles.

Silkolene PRO S 10w-50 ester Fully Synthetic;)

My *opinion* and it is JUST a opinion, is a modern two stroke synthetic in the fuel for tip lubrication, and ash free combustion, and any decent 4 stroke synthetic for the sump, whose hardest jib will be lubing the (mad hot) turbo. I feel trying to make a single oil work in what is effectively a combustion, 2 stroke like environment, and lube the turbos properly is better served by splitting the roles.

--------------------------------------------------------------------------------

Totally agree Chris, have been running mine on 103 RON fuel with Pennzoil synthetic at 100;1 for the last 30000 miles !

Youve been running your Supra on a 2 stroke premix of 100:1?

So in Layman's terms what would be the best oil to use on my UK-spec TT Supra running at around 400bhp (approx. 70bhp more than the standard horsepower) ????

Originally posted by Matt Harwood

All sounds like good info so far, but the ultimate question...

 

Can you tell us what oils use a genuine Ester/PAO?

A very difficult question to answer as most of what you see around is hydrocracked stuff (even Castrol 10w-60).

There are some products however that are PAO or PAO/Ester blends out there.

For example, all 0w oils will have a PAO content as to meet the 0w test (-35 degC) and the sae number 30,40 etc it has to be as a mineral oil cannot achieve these wide ranges.

The same goes for most 5w-40's, they may not be fully synthetic in the true sense of the word but they will contain a percentage of the good stuff (the higher the better).

10w's and 15w's etc, almost all are hydrocracked as mineral oils can manage the "w" temps much easier on their own.

So what should you look out for, well, there are the totally overpriced Redline, Royal Purple etc which are US oils or a little closer to home you have the following oils

Silkolene PRO S 5w-40 and 10w-50 (Ester/PAO)

Mobil 1 (PAO)

Fuchs Titan Supersyn Range (PAO)

Motul 300V (PAO/Ester)

Most others ignore unless the Oil company will tell you what's in them (and in most cases they won't) and................

Don't be misled by the statement "its synthetic sir" ask what type of synthetic!

We can and do supply Silkolene, Fuchs and Mobil to Clubs by mail order through our "Clubs Oil Scheme", if the Club is interested then ask them to email me.

If you would like prices, drop me an email.

You will find some good technical data here:

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

Hope this helps

Cheers

Simon

Originally posted by dangerous brain

Here here. You say that aero jet engines use fully "proper" synthetic oils. So would my castrol mil designation general gas turbine oil OX26 have been any good an oil to whack in my supra?

From a compositional point of view I'm sure its got the best stuff in it, whether it's suitable for your car is another matter.

Cheers

Simon

Originally posted by Chris Wilson

My *opinion* and it is JUST a opinion, is a modern two stroke synthetic in the fuel for tip lubrication, and ash free combustion, and any decent 4 stroke synthetic for the sump, whose hardest jib will be lubing the (mad hot) turbo. I feel trying to make a single oil work in what is effectively a combustion, 2 stroke like environment, and lube the turbos properly is better served by splitting the roles.

You know your stuff. The best form of UCL is a good 2 stroke oil and it works well in older V8's etc.

I have a renesis and apparantly they have solved the seal problems of old but still do not recommend "true" synthetics as the engine has not been tested on them, only MC petroleum oils.

They, Mazda UK, don't know much about oils. If they did, they would know that Esters swell seals and PAO's shrink seals, therefore in the correct blend there is no problem with these oils however as they are owned by Ford, the stock recommendation is 5w-30 meeting Ford WSS-M2C913B/A.

Once my warranty's up, I'm on Silkolene PRO S 5w-40 (ester/pao) as its a top oil!

Cheers

Simon

Originally posted by BigRoy

Silkolene PRO S 10w-50 ester Fully Synthetic;)

In my professional opinion, probably the best and most realistically priced ester/pao for your Supra.

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

Cheers

Simon

Originally posted by AJI

So in Layman's terms what would be the best oil to use on my UK-spec TT Supra running at around 400bhp (approx. 70bhp more than the standard horsepower) ????

Any one of Silkolene's PRO S or PRO R Oils - Proper synthetic oils with a good slug of ester.

Why are esters so good?

Due to their structure, ester molecules are “polar”; they stick to metal surfaces using electrostatic forces. This means that a protective layer is there at all times, even during that crucial start-up period. This helps to protect cams, gears, piston rings and valve train components, where lubrication is “boundary” rather than “hydrodynamic”, i.e. a very thin non-pressure fed film has to hold the surface apart. Even crank bearings benefit at starts, stops or when extreme shock loads upset the “hydrodynamic” film.

Hope this helps

Cheers

Simon

Ok so from the first post i've picked up that, extra bhp = extra heat to disipate and can cause degradation of 'lesser' oils. Not a difficult point to grasp, however is there not a case for just increasing your oil cooling? or is there too much localised heating in certain areas to stop the degradation.

And is this degradation serious if the oil is changed more frequently than the recommended intervals (something already done by most modded car owners)

What i'm saying is if a stock TT supra has made its way to 250+K miles on 4.5K mile intervals (or is it 6K per the uk handbook?) and bog standard oil, then should bpu cars running 400ish bhp and say changing the oil every 3K miles be ok on the same regular oil?

Scooter.

All of what you have said is basically correct. If you're not using proper synthetics then regular oil changes are required as the oil "shears" much more quickly.

Synthetics do not require this frequency of change and have better lubricity. At the end of the day, it's a cost/benefit equation which if done properly will tell you that "true" synthetics actually save money and give better protection long term.

DO SYNTHETICS REQUIRE A 3000 MILE OIL CHANGE?

The necessity of 3,000 mile oil changes is a myth that has been handed down for decades. Well it’s good for the oil companies as they sell more oil!

Synthetic oils are much better value for money than petroleum oils, you just have to know how to use them to your benefit.

If you're one who thinks that synthetics are just a marketing ploy to make more money off the same bottle of oil, read through this and judge for yourself.

The whole point of using a synthetic oil is peace of mind, knowing that you can trust the oil in your car to protect the engine.

There are only a few basic reasons why it is necessary to change your oil, and they all, in the end, have to do with decreased protection of your engine and decreased performance.

If these elements can be minimized, then there will be little or no reason to change the oil.

What causes the oil to breakdown?

Firstly, all oil breaks down. That generally will include basestocks and additives (actually additives are really "used up" rather than broken down.

The most significant difference from one oil to another is how quickly breakdown occurs. Although there are many factors that contribute to the breakdown of an oil, temperature is one of the most important.

Petroleum oil begins to break-down almost immediately. A high quality synthetic, on the other hand, can last for many thousands of miles without any significant reduction in performance or protection characteristics. Synthetics designed from the right combination of basestocks and additives can last indefinitely with the right filtration system.

The first major difference between petroleum and synthetic oil is heat tolerance. Flash point is a technical specification referenced by most oil manufacturers which is an indicator of heat tolerance.

The lower the flash point of an oil the greater tendency for that oil to suffer vaporization loss at high temperatures and to burn off on hot cylinder walls and pistons. This leads to oil thickening and deposit build-up on critical engine components. So, the higher the flash point the better. 200 degrees C, is the absolute MINIMUM to prevent possible high consumption and oil thickening due to burn-off.

Today's engines are expected to put out more power from a smaller size and with less oil than engines of the past. Therefore, the engines run much hotter than they used to. That puts an increased burden on the oil. Synthetics are up to the task.

Although synthetics are MUCH less prone to burn-off than are petroleum oils, there is still a small amount of burn-off during extremely high temperature operation.

The manner in which petroleum and synthetic oils burn off is important. As a refined product, petroleum oil molecules are of varying sizes. So, as a petroleum oil heats up, the smaller molecules begin to burn off. Deposits and sludge are left behind to coat the inside of your engine. In addition, as smaller particles burn off, the larger, heavier molecules are all that is left to protect the engine. Unfortunately, these larger particles do not flow nearly as well and tend to blanket the components of your engine which only exacerbates the heat problem as friction builds-up.

Synthetic oils, on the other hand, because they are not purified, but rather designed within a lab for lubrication purposes, are comprised of molecules of uniform size and shape.

Even if a synthetic oil does burn a little, the remaining oil has the same chemical characteristics that it had before the burn off. There are no smaller molecules to burn-off and no heavier molecules to leave behind.

Synthetics contain far fewer contaminants than petroleum oils since they are not a refined product. As a result, if oil burn-off does occur, there are few, if any, contaminants left behind to leave sludge and deposits on engine surfaces. Obviously, this leads to a cleaner burning, more fuel efficient engine.

It is also important to note that synthetics do a much better job of "cooling" engine components during operation. Because of their unique flow characteristics, engine components are likely to run 10 to 30 degrees cooler than with petroleum oils. This is important, because the hotter the components in your engine get, the more quickly they break down.

Additive depletion comes into play when discussing oil drain intervals. If additives are depleted, the oil cannot effectively do it's job. So, the oil must be changed.

It is true that the additives in many oils begin breaking down after only a few thousand miles. What needs to be recognized is that there are different quality "grades" of additives just as there are different quality grades of just about any other product that you buy.

Many oil companies are using the same additives in their oils as all of the other companies because they are cheap. That's why the oil costs less. You get what you pay for!

If they were willing to spend the money on top-quality additive packages for their oils, every synthetic on the market would be recommended for extended drain intervals, and they would all be more expensive.

The technology has been around for years. The problem is that oil companies make more money selling a cheaper grade oil and making sure that you change it more often.

What do the oil additives in your oil do?

Viscosity Retention

Additives are used to maintain a stable viscosity over a wide temperature range. Synthetics need less of these additives than petroleum oils do because synthetic basestocks maintain a fairly stable viscosity by themselves. Also, the additives that are used are more stable than those used in petroleum oils.

As a result, petroleum oils must be changed often because they quickly become unable to retain the viscosity levels necessary to protect your engine (their high temperature viscosity drops off).

Synthetic oils don't really have that problem because both the basestocks and the additives are more stable.

Additives are also used to keep oil contamination in check and to keep it from damaging your engine. These additives keep potentially wear causing contaminants suspended and contained in your oil so they don't cause excessive wear or deposit build-up within your engine before your filter can remove them.

Synthetics generally have higher additive treat rates than petroleum oils (in addition to using higher quality, more expensive additives), so they can perform this contaminant control function for a much longer period of time than a petroleum oil can.

Hope this explains

Cheers

Simon