Oilman

In this cold weather, it is beneficial to use an oil that has good cold start flow properties as it will get to the parts of the engine that need it far more quickly. The "w" number which means winter is the key here and the lower the better. It may seem odd but a 15w or 20w will struggle to get around the engine in very cold temps and I would strongly recommend a 10w or better still a 5w for better cold start performance. 90% of all engine wear occurs on cold start because the oil get thicker the colder it is which causes engine wear. These numbers explain what I mean and bear in mind that the oil will be the following thickness at 100degC (sae 40 = 14cst, sae 50 = 18cst and sae 60 = 24cst) At 0degC these are the numbers (thick!) Grade.................At 0C.........At 10C...........At 100C 0W/20.............328.6cSt......180.8cSt..........9cSt 5W/40.............811.4cSt......421.4cSt..........14cSt 10W/50............1039cSt.......538.9cSt..........18cSt 15W/50.............1376cSt.......674.7cSt.........18cSt 20W/50.............2305cSt.......1015cSt..........18cSt If you are using anything more than a 10w oil, always warm the car properly before driving it as the oil needs time to circulate. Just a word of warning really. Cheers Simon

I posted this a very long time ago but for the benefit of the newer members and those that missed it first time around, some enlightening facts from and expert! A word of caution – You get what you pay for! Below is an article written by John Rowland, Silkolene/Fuchs Chief R & D Chemist for 40 years. Quote: 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”. Needless to say, 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! Unquote: This article is something that all car owners should read and understand before buying oil and I’ve posted this with Johns permission. Cheers Simon

Ok, will do. Cheers Simon

YHM Cheers Simon

I haven't forgotten you, I'm still looking for one :) Cheers Simon

It's good stuff, have it on my shelves. Cheers Simon

10w is fine for winter use, even in chilly Scotland. I would still use the 10w-50 as the most suitable option. Cheers Simon PS. Nice to be back. Went away for a while to cool down after some heated discussons. It can be a thankless task at times :headvswal

The "best" is certainly not Maganatec as it's a petroleum based oil (mineral). If you want the best then synthetic (non-petroleum) pao/ester is the way to go and although they cost more they are worth it for the higher levels of protection and stay in grade properties. I would recommend Silkolene PRO and Motul 300V as being two great oils Cheers Simon

Indeed a wise man. Less wear due to better circulation. Cheers Simon

Still recommend 10w-50 for the modded and tracked cars. 5w-40 or 10w-40 would be better for the stock road cars. Cheers Simon

Use the viscosities your handbook says - 10w-60 is not mentioned! Cheers Simon

Simon is away till next week. I will get him back on it monday for you. ;) Cheers Guy.

Let me see what I've got and I'll get back to you. Cheers Simon

Viscosity Index Improvers. An oils viscosity will decrease as the engine temperature rises. Viscosity Index Improvers are added to reduce this thinning. They are a key addative in the production of multigrade oils. VI Improvers are heat sensitive long chain, high molecular weight polymers that minimise the viscosity loss of the oil at high temperatures. They work like springs, coiled at low temperatures and uncoiling at high temperatures. This makes the molecules larger (at high temps) which increases internal resistance within the thinning oil. They in effect "fight back" against the viscosity loss in the oil. "Shearing" The long chain molecules in VI Improvers are prone to "shearing" with use which reduces their ability to prevent the oil from losing viscosity. This "shearing" occurs when shear stress ruptures the long chain molecules and converts them to shorter, lower weight molecules. The shorter, lower weight molecules offer less resistance to flow and their ability to maintain viscosity is reduced. This shearing not only reduces the viscosity of the oil but can cause piston ring sticking (due to deposits), increased oil consumption and increased engine wear. Like basestock quality, VI Improvers also vary in quality. As with many items the more you pay, the better the finished article and more expensive, usually synthetic oils are likely to incorporate better VI improvers. All other things being equal the less VI improver an oil contains, the better it will stay in grade by resisting viscosity loss. Which oils require more VI Improvers? There are two scenarios where large amounts of these polymers are required as a rule. Firstly in "wide viscosity span" multigrades. By this I mean that the difference between the lower "W" number and the higher number is large for example 5w-50 (diff 45) and 10w-60 (diff 50) are what is termed as "wide viscosity span" oils. Narrow viscosity oils like 0w-30 (diff 30) or 5w-40 (diff 35) require far less VI Improvers and therefore are less prone to "shearing". Secondly, mineral and hydrocracked (petroleum synthetic oils) require more VI Improvers than proper PAO/Ester (Group IV or V) synthetic oils as they have a higher inherent VI to begin with, this is due to differences in the molecular straucture of the synthetic base oils compared to mineral oils It is a fact that many synthetics require significantly less VI Improver to work as a multigrade and are therefore less prone to viscosty loss by shearing. Cheers Simon

This will be a very thin oil, around 14cst at room temp. What's it for? Cheers Simon

Indeed, read some of my posts 10w-60 is not mentioned and I don't recommend it because of this. 10w-40 or 10w-50 if modded and used on track is my recommendation. Do a search for posts by oilman, you'll find all the info. Cheers Simon

My database lists ATF Dexron II. Cheers Simon

Its Silkolene SYN 5 75w-90 Cheers Simon

It's not knackered. Cheers Simon

If the engine is in good nick and not losing or burning oil yes. Cheers Simon

10w-40 or 10w-50 is fine. Just bear in mind that Magnatec is a semi-synthetic though. Cheers Simon

Look elswhere, it won't be the oil. Cheers Simon

Shall we just say you can buy better and leave it at that ;) Cheers Simon

No free trading, you are not a trader on this forum, please see mac1 if ou wish to trade

All the figures are here: 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 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 Below 15 API: SE SAE 5W-30 Hope this helps, Cheers Simon