Ο χρήστης italakias έγραψε:
παντως αν το λαδι εχει ακριβως τις ιδιες προδιαγραφες δλδ ουτε καλυτερες ουτε χειρωτερες,ειναι υποχρεωμενοι να το βαλουν.
Μάλλον δεν παρακολουθείς συνεχώς τι γράφεται εδώ μέσα, 2 σελίδες πιο πίσω είχα βάλει αυτό.....
Πιο απλά, το πρώτο νούμερο στο λάδι είναι το ιξώδες του βασικού λαδιού στο οποίο μπαίνουν τα πρόσθετα που το καθιστούν πολύτυπο ( Μultigrade ), τι πρόσθετα είναι αυτά, τι ιξώδες προσδίδουν στο λάδι στους 100c, τι καθαριστικά περιέχουν κλπ, είναι άλλο θέμα από το βασικό λάδι που το ιξώδες του είναι αυτό που περιγράφει το πρώτο νούμετο πχ. 0w ή 5w ή 10w.
Επίσης να πω εδώ ότι όταν υπάρχει στενή συνεργασία κατασκευαστή αυτοκινήτου με κατασκευαστή λαδιών πχ Renault / Elf - Peugeot / Total και άλλες συνεργασίες που υπάρχουν, πρέπει να ακολουθούμε τις οδηγίες του κατασκευαστή γιατί ναι μεν ένα λάδι μπορεί να καλύπτει τις τυποποιημένες προδιαγραφές SAE, API κλπ, αλλά ο κατασκευαστής Renault όταν λέει 5-30 Elf ξέρει ότι πχ τα κουζινέτα του χρειάζονται λίγο περισσότερο στάχτη, ή φώσφορο, ή τσίγκο ( Zink κατά το Ελληνικότερο ) και λέει στην Elf τις παρατηρήσεις του και βελτιώνουν το συγκεκριμένο πρόσθετο προσθέτοντα ή αφαιρώντας ή αλλάζοντας την κοκομετρία του.
Αυτές τις επί μέρους λεπτομέρειες δεν τις καλύπτει καμμία τυποποιημένη προδιαγραφή, οπότε όταν υπάρχει πρόταση του κατασκευαστή για συγκεκριμένο λάδι την ακολουθούμε αν θέλουμε να έχουμε ήσυχο το κεφάλι μας, βέβαια οι λεπτομέρειες ενός λαδιού σε φθορά δεν φαίνονται αμέσως, χρειάζεται πάνω από 100.000 χλμ για να φανεί ένα ακατάλληλο σχετικά λάδι, εκτός ειδικών περιπτώσεων μεγάλης απόκλισης από τις προδιαγραφές, ανηλεές και συνεχές σκίσιμο του μοτέρ κλπ.
Αν νομίζεις επίσης ότι δεν ισχύει τίποτα από αυτά, τι άλλο να πω δεν ξέρω. Ξέρεις εσύ τις αναλογίες των πρόσθετων που υπάρχουν σε κάθε λάδι ? Το γράφουν πουθενά οι τυποποιημένες προδιαφραφές που αναφέρεσαι ? Όταν προτείνει κάτι ένας κατασκευαστής έχει φτιάξει το προϊόν του με διαφορετική συνταγή, οι προδοαγραφές είναι για να υπάρχουν κάποια βασικά μεγέθη, από εκεί και μετά υπάρχει η επι μέρους διαφοροποίηση που δεν αναφέρεται πουθενά.
Sodium
This type of product was one of the initial materials tested in the US when Pb levels in leaded gasoline were
reduced to 26mg per litre. Because of these moves a programme was run jointly by the US Environmental
Protection Agency (EPA) and the US Department of Agriculture (USDA) on two basic chemistries, Sodium being
one.
Testing in various engines showed that at the recommended treatment some degree of protection against
VSR was provided. However, at four times the recommended treatment VSR was eliminated. A negative finding
during the testing was that oil black deposits were found in the inlet tracks.
Sodium is also known to form low melting point eutectics in very hot regions. This is known to result in erosion
problems, particularly with turbochargers. As a consequence of these findings, Sodium has been withdrawn
from the list of chemistries being considered for use in Lead Replacement Petrol (LRP).
Phosphorous
This material was also included in the original EPA/USDA study. The treatment was tested at about double
the recommended treatment and reduced VSR although a wear rate value of 0.022ins/100 hours still signifies
future problems.
Additionally, this additive caused deposits to form in the inlet valve area of the engine to the extent that one
valve was unable to close fully and was starting to burn at the test completion - 200 hours.
In these tests the fuel treatments (Sodium/Phosphorous) were found to contaminate the crankcase oil. Such
contamination has a deleterious effect on the oil normally causing it to thicken. Phosphorous is also known
to be a severe poison for catalytic converters which could cause additional problems if mis-applied when
filling a car with petrol.
Potassium
With the demise of Sodium, Potassium has become its natural replacement since test work has shown that
Potassium will provide similar levels of VSR protection to Sodium. There is a large body of evidence which
demonstrates that potassium in the presence of lead alkyls or associated halogen chemistry scavengers leads
to inlet valve burning. While leaded fuel is still available any mis-fuelling and the use of after treatments
containing this type of product will remain a concern.
Potassium as a fuel additive has been previously used, not as a VSR treatment but as a fuel performance
enhancer. Many motorists may possibly recall the major problems which many cars, and the models of one
major car producer in particular, encountered when their cars were run on a well known brand of petrol.
Metal Pellets
There have been claims over many years that using metal pellets either in the fuel tank or fuel lines reduces
VSR. One such device which uses tin pellets was tested and reported in a Classic Car magazine in 1989/90
period.
The published results indicated that VSR protection was not achieved which is hardly surprising since the
solubility of metallic tin or lead in petrol is very low, in the order of one part in 10 million (VSCC !((!). This is
in contrast to the 30-50ppm of lead concentration generally considered as the minimum for protection.
Manganese
Manganese in the form of Methylcyclopentadienyl Tricabonyl (MMT) has been used in virtually all Canadian
unleaded petrol without any problems for well over 20 years. Its original use was for the self same reasons
that lead was first used - namely to increase octane.
Like the lead it can replace, MMT also protects soft valve seats from recession so it can be said that MMT is
the closest alternative to lead.
With MMT being available since the early 1970’s it has been subjected to the most vigorous testing of any fuel
additive in history with extensive test data to support its important feature:
Helps reduce intake valve deposits in conjunction with fuel detergents.
Does not contribute to valve stick either alone or in combination with detergents.
Completely safe in turbo-charged engines.
No adverse engine deposits formed.
Compatible with all construction materials including plastics and elastomers.
Insoluble in water preventing any interaction problems.
MMT has gained US EPA Waiver for use in unleaded gasoline along with Pipeline distribution approval due
to its non-surfactant properties.
Toxicity of VSR Materials
Any product which is added to fuel to be burnt in engines and expelled through the exhaust will have an effect
on emissions. Of all the treatment chemicals examined, only MMT has been subject to in-depth studies. These
have shown that no problems are posed in respect of emissions, hence the approval of US EPA.
For catalytically equipped vehicles statistically significant reductions in carbon monoxide (CO) and oxides of
nitrogen (NOx) have been observed.
Manganese is a naturally ocurring element found in soil, water, food and all living organisms. In the combustion
process the Manganese forms Manganese Oxide (Mn3 O4) and only about 0.1% Manganese is emitted from
the exhaust. Very high concentrations of Manganese (30,000 mg/m3) can have side effects (Parkinson like
symptoms) but a recent study conducted by Research Triangle Institute in Toronto, Canada, showed that no
citizens of that city are even exposed to the safe recognised scientific level which is set at 0.025μg/m3.
Little or no toxicology data is available for other metallic systems but it is considered that phosphorous
compounds can lead to highly toxic emissions similar in nature to organo-phosphates which are highly toxic
ie. Gulf war syndrome and the use of sheep dip on farms.
