af oakey » tors jun 24, 2010 15:32 pm
Hej Heine,
Før du læser resten af dette lange indlæg har jeg et godt råd: Lad være med at blande forskellige olieprodukter.
Hvis du gerne vil vide mere så læs resten. Indlægget fra WikiAnswers giver god mening og dækker mere end bare motorolie.
Hvis engelsk ikke er dit foretrukne sprog kan jeg godt levere et sammendrag af delen om motorolie på dansk.
Der er nogle fagudtryk som man kan finde betydningen af på nettet, for eksempel så dækker udtrykket 'API' over massefylden af olien.
Den ide at olie er olie stammer fra motorernes stenalder. Når man ikke ved ret meget om et emne (det gælder også undertegnede) er det nemt at sige: det kan jo ikke være ret svært.
Det er min erfaring at når man graver sig ned i et emne finder man hurtigt ud af at tingene ikke er så simple som de så ud til fra starten.
Kort sagt: du kan bruge olivenolie til at smøre akslen på din trillebør, men hvis du vil gøre det bedste for din bil skal du bruge andre smøremidler.
oakey
Jeg har klippet dette indlæg på WikiAnswers som giver lidt indblik:
Is it harmful to mix regular motor oil with synthetic?
Answer
Synthetic and conventional will not "mix" and synthetic creates a barrier on moving parts, that conventional cannot pass. So, too much synthetic, as in a 50/50 blend, will be like running an 8 quart system on 4 quarts, without starving the oil pump. It will break the synthetic oil down quicker... in conclusion: The correct combination will give you no problems and will yield the benefits of both conventional and synthetic. With Engine/Motor Oil, the maximum amount of synthetic recommended is 25%. Foaming will develop if more is used, and the foam will counteract with lubrication. Higher-priced synthetic blends have more synthetic and/or more friction modifiers. Synthetic Blend as mentioned earlier is not as cost efficient as adding your own bottle of full synthetic for every 3 quarts of conventional. Just make sure the weight is the same.
Additional info or FYI:
Gear Oils can be combined, but with higher regards to percentage than as with oils. I wouldn't play chemist on my vehicle, but if need be to combine, my professional advice would be that the amount of synthetic combined with gear oil would be as little as 1%, so in other words, if you are not certain what gear oil is in... say, your differentials, drain and refill and do not worry about the remainder of gear oil that is in the differential... or leave the old gear oil (unless burnt) and simply top it off with something like Lucas Oil Conditioner that is recommended for gear boxes and will interact with either conventional or synthetic.
As a whole, greases will not blend/fold unless they are of the same "base" and this is more extreme when in regards to synthetic & conventional. Bearings need to fold the grease and exchange old grease with new grease as the bearings pull the new grease in and push the old grease out. The above mentioned barrier will contain one or the other and not allow the other to fold with it. This is where it is important to know what's what. I'll use u-joints as an example here:
When purchased, if the u-joint is packed with Lithium-based grease from the factory and John Doe's 15-minute Lube pumps the u-joints with moly-based conventional, or worse, silicon-based synthetic...
... even if they say "we flushed out the old grease with the new grease", they will not be able remove 100% of the old grease without actually removing/disassembling/cleaning/repacking/reinstalling the u-joint. So, the lithium-based grease will never be refreshed with new grease; It will eventually burn up around the bearings causing the bearing surface to disintegrate and mix in with the burnt grease, ultimately leading to a more speady premature failure due to metal mixed in with the grease. Anyone who has disassembled a bad u-joint may have seen what resembled the absence of bearings + grease and nothing but graphite powder inside. The graphite powder is* the bearings and the grease was either burnt up or thrown out when the tolerances (or slack/slop) became extreme between the yoke and cup after the bearings became worn.
Furthermore:
It could be damaging to an engine to use the wrong API specification oil:
1) Engines that were meticulously engineered/designed using API SH oil (Honda motorcycles for example, but automotive is included) can prevent a higher API rating from sticking to the moving parts in areas such as the main bearings-to-crank journals. If the oil is thrown off the bearing, it is almost as anti-beneficial as no oil at all.
2) When the vehicle has a "flat tappet" style valve train. Alkyl-zinc, now replaced with the anagram "ZDP" or "ZDDP", is needed as a cushion between the camshaft and lifter. SM rated oils are only compatible with API MIL-specs for SJ & SL. Additives such as STP Oil Treatment for 4-cylinders (more ZDP than for 8-cylinders) has a lower ZDP content than the pre-1996 formula. Special Racing Oils or Motorcycle Oils commonly contain more ZDP to protect main bearings and valve train, as well as additives for break-in periods, which commonly contain so much ZDP that they are recommended to be drained at the first scheduled oil change. The break-in additives can be used in part, to give the .1% (1000ppm)- .16% (1600ppm) content as specified in your owner's manual. Too much for too long can cause sludge, so the 41600ppm+ in say 1pt of the additive, even if reduced by means of diluting with 8 quarts of oil, resulting in a content of a 2600ppm. ZDP/ZDDP was lowered by the SAE/API to extend the life of catalytic converters. If your vehicle did not come equipped with one, the need for lowed ZDP/ZDDP does not apply to your vehicle and the need for more ZDP/ZDDP most likely does... but will not hurt anything otherwise.
Nu:
S60T aut. P24 2005
V70T aut. P26E 2008
Før:
850T aut. st 1996, 940T st 1998, 850 st 1994, 240 st 1988, 240 van 1981
Ford Granada Van 1973, Renault 4L 1969, VW T2 1970, Morris Mascot 1970, Renault 4L 1962, - alle rustet op.