Mitovi i legende o motornim uljima (drugi deo), Myths and Legends about engine oils (part two)

Legenda #1: Sintetička ulja su uvek bolja. (Mit #7.4) Zato se uvek trebaju koristiti samo ona.

Objašnjenje legende:

Sintetička ulja jesu bolja (nije mit) ali …

Mineralna ulja mogu biti jednako dobra za mnoge slučajeve (nisu značajno inferiornija). Naročito ona sa dobrim paketom aditiva i koja imaju isti nivo kvaliteta (npr. API SL) kao neka sintetička ulja.

Da li je sintetika vredna veće cene (dodatnih troškova)? Ne uvek! Naročito kod starijih automobila koji nemaju visoke zahteve (API SG, SH ili SJ) i za intervale zamene od 5 do 10 hiljada km. Potrebno je neke od komercijalnih tvrdnji uzeti sa dozom rezerve. Uostalom, neke viskozne kategorije se ne mogu zameniti u 100% slučajeva (15W-40 sa 0/5W-40 ili 20W-50 sa 5/10W-50).

Legend #1: Synthetic oils are always better. (Myth #7.4) Therefore, always should use only those.

Explanation of legend:

Synthetic oils are better (it is not myth) but …

Mineral oils can be just as good for many cases (not significantly inferior). Especially those with a good additive package and which have the same level of quality (eg. API SL) as a some synthetic oils.

Is the synthetic worth the extra cost? Not always!  Especially in older cars that do not have high requirements (API SG, SH or SJ) and change intervals of 3 to 6 thousands miles. You need to take some of the commercial claims with some caution. ). After all, some viscosity grades can not be replaced in 100% (15W-40 with 0/5W-40 or 20W-50 with 5/10W-50).

Legenda #2: Sintetička smanjuju potrošnju goriva.

Nije baš mit ali nije baš tako kako izgleda. Viskoznost je mnogo značajnija za uštedu goriva. Manji je udeo osobina sintetičkog ulja u tome. Kod motora pogotovu kao i u slučaju “mineralnih sintetika” (SHC). PAO ulja (i estri, doduše nešto manje) zaista mogu smanjiti koeficijent trenja ali je to značajnije kod menjača (i menjačkih ulja) i uopšte prenosnika nego u motoru. Dakle nešto je do sintetike ali je više do manje viskozosti, koju ona imaju.

Napomena: Ako koristite sintetička 5W-30 umjesto mineralnih 10W-30 očekuje se da će potrošnja biti 1-2% niža. Izvan grada bi bilo (max.) 1% (i to je više zbog organskih Mo aditiva nego zbog sintetičke osnove) i za gradsku vožnju 2-3% ili čak 3-5% u zimskom periodu. Ali, očigledno je da je potrošnja goriva manja više zbog niže viskoznosti na niskim temperaturama i u početnom periodu od vožnje kada motor nije na radnoj temperaturi.

Legend #2: Synthetic oil improves your fuel economy.

Not exactly a myth but it is not as it seems. Viscosity is more important to save fuel. A smaller part is in properties of synthetic oil. In particular when engine oils are in case and in case of "synthetic mineral" (SHC). PAO oils (and esters but as no. 2) can actually reduce the coefficient of friction but it is important for gears (and gear oils) and general transmissions than the engine. Therefore something is due synthetics but more is to less viscosity which they have.

Remark: If you use synthetic 5W-30 instead of mineral 10W-30 it is expected that fuel consumption would be 1-2% lower. Outside of city it would be (max.) 1% (and it is more due to organic Mo aditives than to synthetic) and for city driving 2-3% or even 3-5% in the winter. But it is obvious that fuel economy is more due to lower viscosity on low temperatures and in initial period of driving when engine is not on working temperature.

#8

MIT: Ulje treba menjati na 3-6 meseci i na 5000 do 7500km.

Stvarnost:

Ulje se menja prema preporuci proizvođača vozila. Intervali zamene ulja mogu biti mnogo duži, 30.000km ili čak 50.000km (u Evropi) [ili do 15000 milja u Americi].

Pogled sa strane: Ako ulje menjate mnogo češće nego što je neophodno, vi prosto povećavate troškove podmazivanja i imate mnogo više rabljenog ulja. Vidi takođe #8.1 i # 8.2

MYTH: Oil should be changed every 3-6 months or 3,000  to 5,000miles.

Reality:

Oil should be changed according to the manufacturer’s recommendations. The oil change intervals could be much longer, 30,000km or even 50,000km (in Europe) [or to 15,000 miles in US].

Side way of the myth: If you changing the oil more often than necessary, you simply will have higher costs of lubrication and much more wastes oil. See #8.1 & # 8.2 also.

# 8.1

MIT: Možda (i) ne moram da menjam na kraće vreme ali time produžavam vek motoru.

Realnost: Potpuno pogrešno. To uopšte neće pomoći u odnosu na dobro odmeren interval zamene.

MYTH: Maybe I do not have to change oil in shorter intervals but it prolongs engine life.

Reality: This is completely wrong. That does not gonna help in relation to well set change interval.

# 8.2

MIT: (Ali) ja vozim po gradu i to su teški uslovi pa moram da prepolovim ili još više smanjim normalan interval zamene ulja. Uostalom to tvrdi i proizvođač vozila.

Realnost: Po ovome, i ako je istina, većina automobila trebaju da menjaju ulje po preporuci proizvođača vozila za teške uslove vožnje.  Gradska vožnja samo po sebi to nije.

Pogled sa strane: Ovo je za dužu priču. Čak ni taksi vožnja NE mora (ali može) automatski da znači izmenu za teške uslove vožnje. Možda samo ne treba ići na maksimalnu vrednost intervala zamene i ništa više od toga.

MYTH: I drive almost entirely in the city. These are the difficult driving conditions. Therefore, I need to halve or more reduce oil change intervals. After all that says and the vehicle manufacturer.

Reality: According to this, and if it is true, most cars should have their oil changed on the manufacturer’s recommended for severe driving conditions. Urban driving by itself is not.

Side way of the myth: This is a longer story. Even the taxi driving does not have to (but can) be condition for the heavy-duty driving . Maybe you just need not to go to maximum change intervals and nothing more than that.

#9

MIT: Sipanje ATF-a (recimo 20-30% u ulju) pre zamene (uz rad motora na leru) će očistiti motor.

Realnost: Ovo je loša ideja.

Objašnjenje: Ima mnogo boljih načina da se očisti motor (vidi tekstova na blogu o tome). ATF nema deterdženata (ili ima vrlo malo) a sami disperzanti nisu bog zna kakva garancija da će se motor isprati. ATF ima nisku viskoznost pa na tome (verovatno) i počiva mit, ali to nije dovoljno.

MYTH: Adding a some ATF (eg. 20-30% in oil) to your engine before an oil change (with some engine idling) will clean the engine

Reality: This is a bad idea.

Explanation: There are many better ways to clean up the engine (see this blog posts about it). ATF has no detergents (or very little) but dispersants that are not guarantee for the engine flush. ATF has a low viscosity and (probably) it is basis of the myth, but it is not enough.

#10

MIT: Ulje iz bureta je nižeg kvaliteta. (košta manje, zar ne?)

Realnost: Ulja iz većih pakovanja su jeftinija ali je kvalitet isti kao u litarskom pakovanju. Razlika u ceni ambalaže je uzrok za nižu cenu. Ovo važi za renomirane proizvođače inače malo istine u tome može da bude.

Pogled sa strane: Dve činjenice ostaju nesporne. Iako je u buretu isto ulje kao i u flaši, lakše je da ono, zbog nepravilnog skladištenja i dugog vremene pražnjenja bureta, više i brže izgubi na kvalitetu. Osim toga, većim pakovanjima se lakše manipuliše; uključujući i falsifikovanje.

MYTH: Bulk oil is of lower quality than bottled oil. (costs less, isn't it?)

Reality: Bulk oil price is generally less expensive, but it is the same quality as packaged product. Difference in the size of the container is reason for lower price. This is true for reputable manufacturers in other cases a bit of truth can be for it .

Side way of the myth: Two facts remain indisputable. Although in the barrel is the same oil as in the bottle, it is easier, because of improper storage, or slow emptying of the barrel, to lose the quality much faster. In addition, larger containers are easier for manipulations; including forging.

P.S.

Čega ću se sve setiti (i naći u skicama) i šta sve ljudi (nesuvislo) pričaju o uljima, prosto je neverovatno. Mislio sam da završim u sledećem post-u ali izgleda da sam tek na pola posla.

I wanted to finish in the next post but it seems that I'm done only half of the job. Quantity (and kind of) false claims about motor oils is amazing.