fella31 said:

Woo hoo !! Halfords have a sale on Castrol Magnatek engine oil (Diesel). Time for an oil change for both my little beauties, a) 80k on a Disco TD5 and b) 95k on a Disco 300 should I use 10w 40 or 15w 40 ?

Ta

Alex

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Treworgey 90 said:

How many times do I have to post this?

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Treworgey 90 said:

ffs
IT'S THE SAME STUFF, JUST IN A DIFFERENT PACKAGE AND WITH A DIFFERENT BRAND NAME.

comprende?

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\Ovoline 531
Olex 5W/30 Super Motor Oil which meets the top spec LR asks for, ACEA A1 and B1, and in every respect is EXACTLY what LR say should be used in the TD5

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ericthered said:

[10w-40, it'll making starting easier] does that mean 15w 40 is ok in the summer? or should you stay clear of 15w-40 all together

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Synthetic Base Stocks

Synthetic motor oils have been made from the following classes of lubricants:

* Polyalphaolefin (PAO) = American Petroleum Institute (API) Group IV base oil
* Synthetic esters, etc = API Group V base oils (non-PAO synthetics, including diesters, polyolesters, alklylated napthlenes, alkyklated benzenes, etc.)
* Hydrocracked/Hydroisomerized = API Group III base oils. Chevron, Shell, and other petrochemical companies developed processes involving catalytic conversion of feed stocks under pressure in the presence of hydrogen into high quality mineral lubricating oil. In 2005 production of GTL (Gas-to-liquid) Group III base stocks began. The best of these perform much like polyalphaolefin[citation needed]. Group III base stocks are considered synthetic motor oil in North America[1], but NOT in the European Union.

[edit] Advantages

The technical advantages of synthetic motor oils include:

* Measurably better low and high temperature viscosity performance[citation needed]
* Better chemical & shear stability
* Decreased evaporative loss[citation needed]
* Resistance to oxidation, thermal breakdown and oil sludge problems
* Extended drain intervals with the environmental benefit of less oil waste.[citation needed]
* Improved fuel economy in certain engine configurations.[citation needed]
* Better lubrication on cold starts

[edit] Disadvantages

The disadvantages of synthetic motor oils include:

* Initial costs are usually four times greater than petroleum-based oils, though at one time, man-made oils cost ten times more than petroleum[citation needed]. Initial costs are often mitigated by extended change intervals, which individuals may confirm through used oil analysis (UOA).
* The lower friction may make them unsuitable for break-in (i.e. the initial run-in period of the vehicle) where friction is desirable to cause wear. As many vehicles now use synthetic oils as factory fill, this is less of an issue than it once was.
* Potential decomposition problems in certain chemical environments (industrial use dominantly)
* Potential stress cracking of plastic components like POM (polyoxymethylene) in the presence of PAOs (polyalphaolefins).
* Potential on some older pushrod race engines with roller lifters for the roller itself not to spin with camshaft movement, but rather slide while the roller itself remains either stationary or at a lower circumferential speed than that of the camshaft lobe[citation needed]
* In July 1996, Consumer Reports published the results of a two year motor oil test involving a fleet of 75 New York taxi cabs and found no noticeable advantage of synthetic oil over regular oil[2]. In their article, they noted that "Big-city cabs don't see many cold start-ups or long periods of high speed driving in extreme heat. But our test results relate to the most common type of severe service - stop-and-go city driving." According to their study, synthetic oil is "worth considering for extreme driving conditions: high ambient temperatures and high engine load, or very cold temperatures." [3] This research was criticized by some because most engine damage appears to be caused by cold starts, and their research method may not have included enough cold starts to be representative of personal vehicle use.[4]

[edit] Semi-synthetic oil

Semi-synthetic oils (also called 'synthetic blends') are blends of mineral oil with no more than 30% synthetic oil. Designed to have many of the benefits of synthetic oil without matching the cost of pure synthetic oil. DELPHI introduced the first semi-synthetic motor oil in 1966.[5]

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The-Wappy-One said:

Whats the diffrence between semi sinth and fully sinth?

as i've just been offered 10 liters of 5w40 for 25 quid fully synthetic is that better than 10w50 semi sinth

wappy


Edit __

Answered my own question




Now my only question is whats the diffrence between 5w40 and 10w40, and which is best for my landy

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thebiglad said:

The difference between 5w40 & 10w40 is the viscocity at colder temperatures, w for winter. The practical aspects are that 5w will circulate better at lower temperatures therefore giving more protection more quickly, also due to it's relative thinness, the motor will start easier as there is less drag. The higher figure is the viscocity at operating (therefore higher) temps.

This only works if you are putting in really good quality oils. On most modern engines they have an oil viscocity requirement of 5w30 or even 0w30, which when poured looks like water !!

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girvtheswerve said:

Hey big its me again!

Reet for me ive just replaced oils filter etc after 3000 mile with 15w/40 is that wrong?

knowing me and my mpg issues do i wan to use a lower viscosity oil? like a 10w/40 or a 5w/40 maybe.

Bear in mind '98 300tdi 111k on the clock auto etc does take a hammerin once a month?

5 or 10 or 15w/40 pray tell o wise one?

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