Fully synthetic oil

[cyclist]

I tried fully synthetic and it did seem to clean out some of the crud, After a long discussion with my local supplier I have gone for semi-synthetic and she seems to run quieter and smoother on it. It is thicker ( and a lot cheaper).

[dieselboy]

That's not a balanced question, though. It can work one way, but not the other. A question like that needs two equally balanced alternatives or opposites.

i think we need numbers, square root symbols, plus, divide and the tiny little number 2 on the corner

[turbolover]

Thanks all
Very useful discussion, I dont know why I was thinking that I had a vehicle with latest techonology. After all 1KZ-TE is still fitted in 2003 onward Colorados and 4th Gen Surfs, until 1KD-FTV was interduced in 2006.

Longest thread on Engine oil

[MattF]

Thanks all
Very useful discussion, I dont know why I was thinking that I had a vehicle with latest techonology. After all 1KZ-TE is still fitted in 2003 onward Colorados and 4th Gen Surfs, until 1KD-FTV was interduced in 2006.

Longest thread on Engine oil

Oh yeah, the original question. 10/40 or 15/40 semi-synth. Anything more expensive than that is a waste of money.

[AuldNick]

Non/semi synth oils thin when hot, full synth dont and contain jaggy cleaning agents, engines are built to suit so dont mix 'em.

Anyway the Surf demands regular changes so why buy expensive plastic oil?

2

[Bogus]

Non/semi synth oils thin when hot, full synth dont and contain jaggy cleaning agents, engines are built to suit so dont mix 'em.

Anyway the Surf demands regular changes so why buy expensive plastic oil?

2

I dont think engine designers , design for specific oils. Its the other way around. Its the oil people who "design" improved lubricants, so the argument that the surf was not designed for synthetic is spurious. If something better comes along why wouldnt you use it. Its a strange argument to say that it wasnt around when I was born so Im not touching it.

Saying that, I use Chevron 15/40 diesel engine oil from COSTCO at £27 for 20 litres and change regularly, but I cant see a valid argument for not using a synthetic and changing it less often. Im led to beleive that fully synthetic oils are in better nick after 100,000 miles than minerals are after 1000 miles.

Bogus

[Gamedawn]

I dont think engine designers , design for specific oils. Its the other way around. Its the oil people who "design" improved lubricants, so the argument that the surf was not designed for synthetic is spurious. If something better comes along why wouldnt you use it. Its a strange argument to say that it wasnt around when I was born so Im not touching it.

Saying that, I use Chevron 15/40 diesel engine oil from COSTCO at £27 for 20 litres and change regularly, but I cant see a valid argument for not using a synthetic and changing it less often. Im led to beleive that fully synthetic oils are in better nick after 100,000 miles than minerals are after 1000 miles.

Bogus

I think the argument is comparable to the use of current high grade fuels. If you put one of the "Super" grades of fuel in a Mondeo you see absolutely no advantage in power or fuel economy - apart from the weight savings due to a lighter wallet. Put the same fuel in a car that was designed to use it (or it was designed for) - say an Impreza WRX - and you will get what you've paid for.

[MattF]

Saying that, I use Chevron 15/40 diesel engine oil from COSTCO at £27 for 20 litres and change regularly, but I cant see a valid argument for not using a synthetic and changing it less often. Im led to beleive that fully synthetic oils are in better nick after 100,000 miles than minerals are after 1000 miles.

It's one of those discussions which has a multitude of points to consider. Must agree with AuldNick slightly on this one. (It will be the first and last time I hope). Running a semi-synth in an engine that's designed for full-synth would probably kill it.

The point with full synthetic oil is that it has no, for wont of a better word, contaminants. Every molecule of it is created in a precise manner to an exact size and weight, thereby there are no unknown factors, some of which tend to induce what becomes the actual buildup in a semi or mineral oil. Which is also, ironically enough, why full-synths are believed to have detergent qualities. They don't, other than the ones available in any other type of oil.

However, the fact that they are precision engineered means that the buildup with a full-synth oil practically, if at all, doesn't happen. Any crud in the oil is merely that which is created by the engine and suspended in the oil. Nothing more. With a semi or mineral oil, some of the 'sludge' in the oil is due to constituents of the oil itself.

The guaranteed lubricity of the full-synth is what causes the noted problems with older engines. They are capable of using full-synth, but the fact that it does lubricate so well, without theoretically creating any buildup in the process is why the engine tends to get cleaned of buildup, and leaks have been known to appear. As someone mentioned earlier, a buildup in the right places is no bad thing. Shifting it can sometimes be detrimental, rather than beneficial.

Conversely, as an example of the opposite scenario, the Ford engines that suffered with the sludge buildup some years ago are a prime example of what can happen with newer engines using an incorrect oil. (Black Death I think they coined that one). The engines died because of a sludge buildup, which was remedied simply by using a fully synth 0/30, I believe? The oil they had recommended initially killed the engines.

So, if anyone's still awake after that one, older engines may work on any oil, but be prepared for sudden leaks if any of the gaskets or such are of unknown quality. Place any other oil in a newer engine than the one specified, and be prepared for the fact that it may cough and die. The tolerances are just way too tight on more recent engines to risk deviating from the manufacturers specified oil types.

I'm sure someone will now find a flaw or error in the above.

[AuldNick]

Try dino oil in any Fiat or any other engine designed for plastic and it WILL die within months starting with sticky valves.

One factor that will reduce the life of most motorcycle engines is when new owners insist on running "the best" plastic oil, WRONG, plastic oil wont act in the same way dino oil does IE it wont thin and breakdown = overlube, not instant death but a few thousand miles shaved from engine life expectancy.

And wot MuttF said carbon/poo in the Surf engine aint a bad thing.

[WARRIOR72]

my mrs has a pugrat 307 cc,she took it to the main peugeot dealers to have its 6 month interim service(she only does 3000 miles a year)it was backin there 2 days later after they admitted theyd put semi synth 10/40 instead of fully 5/30 (they even wrote the oil grade theyd used in the service report to incriminate themselves further!!) in and the camshafts wore away so bad she had to have a complete new head and camshafts etc,after about 100 miles!!
i dont know if it was this that displeased her or the fact her lovely new convertible was replaced by a 206 estate auto diesel 'courtesy' car!!

[AuldNick]

You want funny oil go buy a Skoda, lime green @ £45 per gallon (trade). Taxi guys "love" it