I vores Ofte stillede spørgsmål (OSS) besvares de oftest stillede spørgsmål om smøremidler.
Hvilke funktioner har smøremidler?
Et smøremiddel skal have mange funktioner. De vigtigste er, at:
- Holde overflader adskilt under alle belastninger, temperaturer og hastigheder, hvilket minimerer friktion og slid.
- Fungere som kølevæske, der fjerner varmen, der produceres ved friktion eller fra eksterne kilder.
- Forbliver passende stabilt for at garantere en jævn adfærd længere den forventede brugstid.
- Beskytte overflader mod angreb fra aggressive stoffer, der dannes under drift.
- Udvise rengøringsevne og kapacitet til at holde på snavs for at fjerne rester og affald, der kan opstå under drift.
Hvordan laves smøremiddel?
Formuleringen af et smøremiddel består af baseolier og tilsætningsstoffer, der kombineres for at bestemme smøremidlets adfærd under brug, både med hensyn til ydeevne og varighed.
Den endelige smøreoliekvalitet afhænger sædvanligvis af kvaliteten på de anvendte baseolier, som generelt enten er:
- Mineralolier: fremstillet ved destillationsprocessen ved raffinering af råolie.
- Syntetiske olier: som stammer fra særlige fysiske/kemiske laboratorieprocesser.
Hvad er et smøremiddels hovedegenskaber?
De vigtigste egenskaber ved smøremidler, som normalt er angivet i produktets tekniske egenskaber, er:
Viskositet beskriver en væskes flydeadfærd. Smøreoliers viskositet formindskes, når temperaturen stiger, og måles følgelig ved en given temperatur (for eksempel 40°C).
Viskositetsindekset angiver variationer i smøreoliers viskositet ved temperaturændringer. Jo højere viskositetsindekset er, desto mindre påvirkes oliens viskositet af temperaturen.
Flydepunktet henviser til den laveste temperatur, ved hvilken et smøremiddel fortsætter med at flyde. Under flydepunktet har olien en tendens til at blive tykkere og ophører med at flyde frit.
Flammepunktet er den laveste temperatur, ved hvilken en olie-damp-luft-blanding bliver antændelig.
Hvilke fordele er der ved syntetisk oliebaserede smøremidler?
- Lavere volatilitetsniveau i forhold til et sammenligneligt viskositetsniveau (hvilket fører til lavere forbrug).
- Højere viskositetsindeks (et bredere temperaturinterval).
- Større kemisk stabilitet ved høje temperaturer (længere levetid).
Hvordan vælger man den rigtige motorolie?
For at vælge den bedste motorolie skal producentens anbefalinger altid følges. For at identificere det mest passende smøremiddel er det derfor nødvendigt at:
- Se afsnittet i køretøjets vedligeholdelsesmanual vedrørende smøring.
- Identificere producentens foreslåede viskositetsniveau (f.eks. 5W-30, 15W-40 osv.).
- Identificere producentens ydeevnespecifikationer (f.eks. ACEA A3/B4, VW 505,00 osv.).
- Vælge det smøremiddel i Eni-produktudvalget, der kan garantere viskositeten og konstruktørernes strenge specifikationer.
Is this the right Eni engine oil for the car in the workshop?
The right engine oil to be used is given by the proper combination of viscosity and specification profile required by the OEM. While there are various engine oils in the market the first step for the user is quite simple, follow the prescription of the car’s manual. As an alternative consult the Eni Lube Finder by using your vehicle registration plate or by searching for your vehicle. The Eni Lube Finder will recommend the engine oil to be used. In case of doubt you can always contact our Eni technical support or our local distributors.
Can engine oil with the latest specifications be used in vehicles for which an older specification was prescribed?
There is not a general rule. While this is true for example for the API categories which are backward compatible, this is not true for the ACEA categories, for example the C5 category of ACEA is not backward compatible with the other C categories.
For the OEM specification the same principle is valid, there is not a general rule, one needs to know the single specification and follow the indication of the OEM. The best advice we can give is to follow the user’s manual or ask Eni personnel for technical support.
What are the ACEA oil Sequences?
ACEA is the European Automobile Manufacturers' Association and the organization that represents the 15 most important European motor vehicle manufacturers. Among the activities of ACEA there is the definition of the engine oil specifications, so called ACEA Oil Sequences. The sequences, which are updated every few years in order to keep in consideration the latest engine technology development, set the standard for the engine oil. The ACEA oil sequences provide 3 different engine oil categories identified by a letter, each category has different classes, identified by a number, each class meets the requirement of a specific engine.
The different ACEA categories are:
A/B: gasoline and diesel engine oils, suitable for passenger cars without exhaust treatment device.
·A5/B5 offer higher fuel economy due to the lower level of HTHS and need to be used only in the engine which are designed for it.
·A3/B3 and A3/B4 offer lower fuel economy but can provide better protection in some types of engine
C: Catalyst compatibility oils, suitable for passengers cars with exhaust treatment device. In this category there are five different classes:
·C1 and C2 offer better fuel economy due to the lower HTHS, C3 and C4 have higher HTHS
·C1 and C4 are low SAPS oils while C2 and C3 are mid SAPS oils.
·C5, which is the last introduced category, offer very high fuel economy due to the lower level of HTHS and needs to be used specifically in engines designed for it.
E: Heavy Duty Diesel engine oils, suitable for heavy duty engine. In this category there are four different classes.
·E4 and E6 offer longer drain interval while E7 and E9 offer medium drain interval
·E6 and E9 can be used in engines which require limited SAPS level including the Euro VI engines, while E4 and E7 present higher SAPS level and meet the requirements till Euro V engine.
SAPS is referred to the content of Sulphated Ash, Phosphorus, Sulphur, the content of SAPS is important for the compatibility with the exhaust after treatment device.
HTHS stands for High Temperature High Share which refers to how thin the oil film is in running conditions.
Er du interesseret i Eni-smøremidler?
Kontakt os eller vores distributører eller
tilmeld dig Enis nyhedsbrev (EN)