Oilman

This is the statement I am referring to as not correct. I have always recommended 10w oils here, please read my threads. There is no benefit for me to recommend people the wrong oil and my original recommendations of some 6 months ago still stand. Oh and I do sell Castrol RS 10w-60 but do not recommend it here. Cheers Simon

Leigh. The charts published are not mine, they are the manufacturers and are correct in stating that 10w and 15w can be used from -20 degC and above. It is however true that 10w will give better cold start protection. I'm afraid you are wrong about the sae 40, 50 and 60 as these are important numbers. If an oil is too viscous for the car at high temperatures then it can cause wear and long term damage. An SAE 60 is heavier than most SAE 90 gear oils. If an oil is too thick, it de-aerates slowly, leading to cavitation in the oil pump, or the bearings being fed slugs of air along with the oil. Modern pumps do not need oils this thick. We are not talking Ford 1960's designed pumps here afterall. Thick oils are more difficult to pump through the engine. This means more friction will be present than with a lighter viscosity oil. More friction means more heat and you may actually be causing more heat build-up within the engine. It will still provide adequate protection from metal to metal contact but will raise engine temperatures. Over the long term, when engine components are run at higher temperatures, they will wear out more quickly. I disagree that you can simply ignore the second number, it's equally important as the first cold viscosity number. Cheers Simon

Agreed if you are talking about the synthetics vs petroleum oils argument as it's a "no brainer" in favour of synthetics. There is however a need to adhere to the Manufacturers recommended viscosities which are available in all types of basestocks. Personally I would not recommend anything else in a high performance car especially if it's modified or being used on the track. Cheers Simon

Yes that is correct but the required viscosities do not change. The fact that you have a choice on quality today is a good thing (Synthetics have been available for the car market for nearly 30 years by the way) but the Manufacturers recommended viscosities are better followed than not. This is the point I have been trying to make but unfortunaltely the Customer's always right even when he's wrong so "I'll get me coat!" Cheers Simon

Here's the Z32 Nissan, 300 ZX, 300 ZX Twin Turbo (Z32), 1990-1991 Manufacturer: Nissan Motors Co., Ltd., Tokyo, Japan Drive type: r.w.d. Cilinder capacity: 2960 cc Power output: 282 HP/208 kW at 6400 Rpm Engine VG30DETT Petrol, 4-stroke, 6 cilinder, V, 4 valves/cil., Turbo, liquid cooled Cilinder capacity: 2960 cc Capacity: 3.4 liter Filter capacity: 0.4 liter Use: Normal Change 10000 km/6 months OEM recommendation Above -20 API: SG SAE 10W-30 Above -20 API: SG SAE 10W-40 Above -20 API: SG SAE 10W-50 Above -20 API: SG SAE 15W-40 Above -20 API: SG SAE 15W-50 Above -20 CCMC G4 SAE 10W-30 Above -20 CCMC G4 SAE 10W-40 Above -20 CCMC G4 SAE 10W-50 Above -20 CCMC G4 SAE 15W-40 Above -20 CCMC G4 SAE 15W-50 Under severe operating conditions: change every 5000 km or 3 months. Capacity including oil filter and oil cooler. Differential, rear, (4x2) Capacity: 2.1 liter Use: Normal Check 40000 km/24 months OEM recommendation Below 40 API: GL-5 SAE 80W-90 Below 40 API: GL-5 SAE 75W-90 Transmission, automatic Automatic Capacity: 8.7 liter Gears forward: 4 Gears reverse: 1 Use: Normal Check 20000 km/12 months OEM recommendation year-round Dexron IIE - Transmission, manual Manual Capacity: 3.1 liter Gears forward: 5 Gears reverse: 1 Use: Normal Check 40000 km/24 months OEM recommendation year-round API: GL-4 SAE 75W-90 Power steering Capacity: 1.3 liter Use: Normal Check 20000 km/12 months OEM recommendation year-round Dexron IIE - Capacity of models with HICAS: 2 l. Top up only. Hydraulic brakes/clutch system Use: Normal Check 20000 km/12 months Change 40000 km/24 months OEM recommendation year-round Brake fluid, DOT 3 - Grease points/nipples Use: Normal Check 40000 km/24 months OEM recommendation year-round Lithium base multipurpose grease NLGI No. 2 Cooling system Capacity: 10 liter Use: Normal Change 40000 km/24 months OEM recommendation year-round Water with antifreeze (ethylene glycol base) - That's the lot, it's now up to you whether you ignore good advice, it's your car and your money - not mine. Cheers Simon

Here is the Lubricants report for the Z31, Z32 to follow: Nissan, 300 ZX, 300 ZX (Z31), 1984-1989 Manufacturer: Nissan Motors Co., Ltd., Tokyo, Japan Drive type: r.w.d. Cilinder capacity: 2960 cc Power output: 162 HP/119 kW at 5200 Rpm Engine VG30E Petrol, 4-stroke, 6 cilinder, V, 4 valves/cil., liquid cooled Cilinder capacity: 2960 cc Capacity: 4 liter Filter capacity: 0.4 liter Use: Normal Change 10000 km/6 months OEM recommendation Above -20 API: SE SAE 10W-30 Above -20 API: SF SAE 10W-40 Above -20 API: SE SAE 10W-50 Above -20 API: SE SAE 15W-50 Above -20 API: SF SAE 10W-30 Above -20 API: SE SAE 10W-40 Above -20 API: SF SAE 10W-50 Above -20 API: SF SAE 15W-50 Under severe operating conditions: change every 5000 km or 3 months. Capacity including oil filter and oil cooler. Differential, rear, (4x2) Capacity: 1.3 liter Use: Normal Check 10000 km/6 months OEM recommendation Below 40 API: GL-5 SAE 80W-90 Below 40 API: GL-5 SAE 75W-90 Below 30 API: GL-5 SAE 80W Below 10 API: GL-5 SAE 75W Transmission, automatic Automatic Capacity: 7 liter Gears forward: 4 Gears reverse: 1 Use: Normal OEM recommendation year-round Dexron IIE - Transmission, manual Manual Capacity: 1.9 liter Gears forward: 5 Gears reverse: 1 Use: Normal Check 10000 km/6 months OEM recommendation Below 40 API: GL-4 SAE 80W-90 Below 40 API: GL-4 SAE 75W-90 Below 30 API: GL-4 SAE 80W For cold and warm areas: 75W-90 for transmission and 80W-90 for differential carrier are preferable. For hot areas: 90 is suitable for ambient temperatures below 40 degrees Celsius. Power steering Capacity: 0.9 liter Use: Normal OEM recommendation year-round Dexron IIE - Hydraulic brakes system Use: Normal Change 40000 km/24 months OEM recommendation year-round Brake fluid, DOT 3 - Hydraulic clutch system Use: Normal OEM recommendation year-round Brake fluid, DOT 3 - Cooling system Capacity: 11 liter Use: Normal Change 40000 km/24 months OEM recommendation year-round Water with antifreeze (ethylene glycol base) - Cheers Simon

I'll post a full lubricants report for the Nissan 300ZX in the next 24 hours and you will see the point I am making here. No disrespect to owners using 10w-60 but perhaps we should go back to basics and find a technical starting point to discuss around. Cheers Simon

There seems some confusion about how a multigrade works, this may help to explain, posted before on the Oil Recommendations thread. What is a multigrade? A good oil must be quite low in viscosity even when it's cold so that it gets around the engine in a fraction of a second when you turn that key! On the other hand it needs to protect engine components like piston rings at very high temperatures as the engine gets hot without evaporating or carbonising and it must maintain oil pressure. Unmodified thin oils simply can't perfrom this balancing act. The answer is to use a mixture of thin oil and temperature-sensitive polymer which as the oil gets thinner with increasing temperature expands and effectively "fights back", keeping the viscosity at a level to hold oil pressure and film thickness on the bearings. So, these polymers are added to a thin base, 0w,5w,10w etc at cold tempertaures they are "coiled up" and allow the oil to circulate very easily but as the engine and therefore the oil warms up, they begin to "uncoil" into long chains keeping the oil more viscous. It is impossible to make a good 5w-40 or 10w-40 using only mineral oil. The base oil is too thin and evaporates away at high temperatures found in powerful engines that are highly stressed, this is why synthetics are used to build up the oil to cope with the stresses of modern engines. Cheers Simon

Spot on and an sae 60 is even further away from the spec you require which is my point here! Cheers Simon

I'm sorry but that statement is a nonsense unless qualified with the viscosity you are referring to! So how thin is MOBIL1 0w-40? Well, much thinner when cold than anything Silkolene makes. How thin is a 5w-50? Well when cold, as thin as Silkolene PRO S 5w-40. You see any 5w oil will be the same thickness when cold as any other 5w oil. Please state which Silkolene Oil you are referring to. Cheers Simon

These are merely the extremes that different viscosities can operate down to. The point is that at the turn of the key, summer or winter, the thinner the oil the more quickly it will circulate around the engine preventing wear. It is not a coincidence that most OEM's today specify 0w or 5w oils for all year round use. Cheers Simon

What's important in these top oils is the ester content as this is what matters for good lubrication. Esters All jet engines are lubricated with synthetic esters, and have been for 50 years, but these expensive fluids only started to appear in petrol engine oils about 20 years ago. Thanks to their aviation origins, the types suitable for lubricants (esters also appear in perfumes; they are different!) work well from –50 degC to 200 degC, and they have a useful extra trick. 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. Cheers Simon

I'm happy to agree to disagree. I've been through all the reasons before and do not wish to state it all again. It's simply too far out of grade and I certainly do not recommend 10w-60 as a suitable grade for the 300ZX. I'm not a tuner I'm a seller and expert in oils with more than 10 years of experience with many of the brands that I sell, I don't just sell one as that would totally compromise my ability to recommend a suitable oil and not give my Customers a wide enough choice. The oils I sell are here and they are all reputable major brands. As you are a Millers Dealer then I guess you will be able to answer a question that I cannot find the answer to. "What percentage of ester and or pao is in the CFS range of oils?" I know in relation to the oils that I sell so I'm sure that they will tell you. 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

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

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?

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

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

============Announcement============== For those of you that have not visited our website lately to look at all the technical data on there about oils, take another look as the range has been extended to include MOTUL and particularly the 300V Double Ester range. Data is here: http://www.opieoils.co.uk/lubricants.htm Happy browsing! Cheers Simon

Thought this might be of interest to you all. 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. 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

Andrew, You are right, you should not mix mineral and synthetic oil, this is because of the different addative packs contained within the oil, mixing them can cause them to react or cancal each other out. For your car I would suggest a good quality PAO or Ester/PAO synthteic, these are known as true synthetics. Esters assist the additive pack in a motor oil formulation because they are surface-active (electrostatically attracted to metal surfaces), so they help to reduce wear and friction. They are fluid at very low temperatures and at high temperatures they are very chemically stable and have low volatility (don’t evaporate away). They also help to prevent hardening and cracking of oil seals at high temperatures. Take a look at the Silkolene Pro S 10w-50 Tech specs here http://www.opieoils.co.uk/lubricants.htm For a list of options and prices e-mail me a sales@opieoils.co.uk Cheers Simon.

Sorry for not replying but I seemed to have missed this one. Specs, well most of the listed ones 505.00 VW and 229.1 MB are very basic specs and not really fussy over which oils are used. These specs have been surpassed since, MB are now on 229.5 for example. VW 505.00 is as follows: VW 500.00 This is an “old” oil specification and is applicable to engines built before model year 2000 (up to August 1999) Viscosity ratings: SAE 5w-40, 10w-40 or 20w-40 This oil can be used in all petrol and some diesel engines, apart from those referred to under other specifications. It's not really a great spec especially for a performance car like yours which would require a better oil to be honest. What I'm trying to say is it's OK but nothing special and you need something better. Cheers Simon

Your bang on, when the oil is warm it flows a lot better. You will find you will get more out if you do this. Cheers Simon.

An engine oil is in fact thinner at start up, and thicker when warmed up. Basically heat sensitive polymers (VI Improvers) are added to a thin base oil and as the engine warms up, these uncoil to give the oil the upper sae viscosity 30,40,50 etc. This should explain the science for you. VISCOSITY INDEX IMPROVERS As a lubricant basestock is subjected to increasing temperatures it tends to lose its viscosity. In other words, it thins out. This leads to decreased engine protection and a higher likelihood of metal to metal contact. Therefore, if this viscosity loss can be minimized, the probability of unnecessary engine wear will be reduced. VI improvers are polymers that expand and contract with changes in temperature. At low temperatures they are very compact and affect the viscosity of a lubricant very little. But, at high temperatures these polymers "expand" into much larger long-chain polymers which significantly increase the viscosity of their host lubricant. So, as the basestock loses viscosity with increases in temperature, VI improvers “fight back” against the viscosity drop by increasing their size. The higher the molecular weight of the polymers used, the better the power of "thickening" within the lubricant. Unfortunately, an increase in molecular weight also leads to an inherent instability of the polymers themselves. They become much more prone to shearing within an engine. As these polymers are sheared back to lower molecular weight molecules, their effectiveness as a VI improver decreases. Unfortunately, because petroleum basestocks are so prone to viscosity loss at high temperatures, high molecular weight polymers must be used. Since these polymers are more prone to shearing than lower molecular weight polymers, petroleum oils tend to shear back very quickly. In other words, they lose their ability to maintain their viscosity at high temperatures. Synthetic basestocks, on the other hand, are much less prone to viscosity loss at high temperatures. Therefore, lower molecular weight polymers may be used as VI improvers. These polymers are less prone to shearing, so they are effective for a much longer period of time than the VI improvers used in petroleum oils. In other words, synthetic oils do not quickly lose their ability to maintain viscosity at high temperatures as petroleum oils do. In fact, some synthetic basestocks are so stable at high temperatures they need NO VI improvers at all. Obviously, these basestocks will maintain their high temperature viscosities for a very long time since there are no VI improvers to break down. Hope this helps, Cheers Simon

Hmm. Quiet in here. Cheers Simon