Outline · [ Standard ] · Linear+ Uleiuri

The following article is intended to help you make a choice based on more than the advertising hype. Oil companies provide data on their oils most often referred to as "typical inspection data". This is an average of the actual physical and a few common chemical properties of their oils. This information is available to the public through their distributors or by writing or calling the company directly. I have compiled a list of the most popular, premium oils so that a ready comparison can be made. If your favorite oil is not on the list get the data from the distributor and use what I have as a data base. This article is going to look at six of the most important properties of a motor oil readily available to the public: viscosity, viscosity index (VI), flash point, pour point, % sulfated ash, and % zinc. Viscosity is a measure of the "flowability" of an oil. More specifically, it is the property of an oil to develop and maintain a certain amount of shearing stress dependent on flow, and then to offer continued resistance to flow. Thicker oils generally have a higher viscosity, and thinner oils a lower viscosity. This is the most important property for an engine. An oil with too low a viscosity can shear and loose film strength at high temperatures. An oil with too high a viscosity may not pump to the proper parts at low temperatures and the film may tear at high rpm. The weights given on oils are arbitrary numbers assigned by the S.A.E. (Society of Automotive Engineers). These numbers correspond to "real" viscosity, as measured by several accepted techniques. These measurements are taken at specific temperatures. Oils that fall into a certain range are designated 5, 10, 20, 30, 40, 50 by the S.A.E. The W means the oil meets specifications for viscosity at 0 F and is therefore suitable for Winter use. The following chart shows the relationship of "real" viscosity to their S.A.E. assigned numbers. The relationship of gear oils to engine oils is also shown. _______________________________________________________________ | | | SAE Gear Viscosity Number | | ________________________________________________________ | | |75W |80W |85W| 90 | 140 | | | |____|_____|___|______________|________________________| | | | | SAE Crank Case Viscosity Number | | ____________________________ | | |10| 20 | 30 | 40 | 50 | | | |__|_____|____|_____|______| | ______________________________________________________________ 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 viscosity cSt @ 100 degrees C Multi viscosity oils work like this: Polymers are added to a light base (5W, 10W, 20W), which prevent the oil from thinning as much as it warms up. At cold temperatures the polymers are coiled up and allow the oil to flow as their low numbers indicate. As the oil warms up the polymers begin to unwind into long chains that prevent the oil from thinning as much as it normally would. The result is that at 100 degrees C the oil has thinned only as much as the higher viscosity number indicates. Another way of looking at multi-vis oils is to think of a 20W-50 as a 20 weight oil that will not thin more than a 50 weight would when hot. Multi viscosity oils are one of the great improvements in oils, but they should be chosen wisely. Always use a multi grade with the narrowest span of viscosity that is appropriate for the temperatures you are going to encounter. In the winter base your decision on the lowest temperature you will encounter, in the summer, the highest temperature you expect. The polymers can shear and burn forming deposits that can cause ring sticking and other problems. 10W-40 and 5W-30 require a lot of polymers (synthetics excluded) to achieve that range. This has caused problems in diesel engines, but fewer polymers are better for all engines. The wide viscosity range oils, in general, are more prone to viscosity and thermal breakdown due to the high polymer content. It is the oil that lubricates, not the additives. Oils that can do their job with the fewest additives are the best. Very few manufactures recommend 10W-40 any more, and some threaten to void warranties if it is used. It was not included in this article for that reason. 20W-50 is the same 30 point spread, but because it starts with a heavier base it requires less viscosity index improvers (polymers) to do the job. AMSOIL can formulate their 10W-30 and 15W-40 with no viscosity index improvers but uses some in the 10W-40 and 5W-30. Mobil 1 uses no viscosity improvers in their 5W-30, and I assume the new 10W-30. Follow your manufacturer's recommendations as to which weights are appropriate for your vehicle. Viscosity Index is an empirical number indicating the rate of change in viscosity of an oil within a given temperature range. Higher numbers indicate a low change, lower numbers indicate a relatively large change. The higher the number the better. This is one major property of an oil that keeps your bearings happy. These numbers can only be compared within a viscosity range. It is not an indication of how well the oil resists thermal breakdown. Flash point is the temperature at which an oil gives off vapors that can be ignited with a flame held over the oil. The lower the flash point the greater tendency for the oil to suffer vaporization loss at high temperatures and to burn off on hot cylinder walls and pistons. The flash point can be an indicator of the quality of the base stock used. The higher the flash point the better. 400 F is the minimum to prevent possible high consumption. Flash point is in degrees F. Pour point is 5 degrees F above the point at which a chilled oil shows no movement at the surface for 5 seconds when inclined. This measurement is especially important for oils used in the winter. A borderline pumping temperature is given by some manufacturers. This is the temperature at which the oil will pump and maintain adequate oil pressure. This was not given by a lot of the manufacturers, but seems to be about 20 degrees F above the pour point. The lower the pour point the better. Pour point is in degrees F. % sulfated ash is how much solid material is left when the oil burns. A high ash content will tend to form more sludge and deposits in the engine. Low ash content also seems to promote long valve life. Look for oils with a low ash content. % zinc is the amount of zinc used as an extreme pressure, anti- wear additive. The zinc is only used when there is actual metal to metal contact in the engine. Hopefully the oil will do its job and this will rarely occur, but if it does, the zinc compounds react with the metal to prevent scuffing and wear. A level of .11% is enough to protect an automobile engine for the extended oil drain interval, under normal use. Those of you with high revving, air cooled motorcycles or turbo charged cars or bikes might want to look at the oils with the higher zinc content. More doesn't give you better protection, it gives you longer protection if the rate of metal to metal contact is abnormally high. High zinc content can lead to deposit formation and plug fouling. The Data: Listed alphabetically --- indicates the data was not available Brand VI Flash Pour %ash %zinc 20W-50 AMSOIL 136 482 -38 <.5 --- Castrol GTX 122 440 -15 .85 .12 Exxon High Perfor. 119 419 -13 .70 .11 Havoline Formula 3 125 465 -30 1.0 --- Kendall GT-1 129 390 -25 1.0 .16 Pennzoil GT Perf. 120 460 -10 .9 --- Quaker State Dlx. 155 430 -25 .9 --- Red Line 150 503 -49 --- --- Shell Truck Guard 130 450 -15 1.0 .15 Spectro Golden 4 174 440 -35 --- .15 Spectro Golden M.G. 174 440 -35 --- .13 Unocal 121 432 -11 .74 .12 Valvoline All Climate 125 430 -10 1.0 .11 Valvoline Turbo 140 440 -10 .99 .13 Valvoline Race 140 425 -10 1.2 .20 Valvoline Synthetic 146 465 -40 <1.5 .12 20W-40 Castrol Multi-Grade 110 440 -15 .85 .12 Quaker State 121 415 -15 .9 --- 15W-50 Chevron 204 415 -18 .96 .11 Mobil 1 170 470 -55 --- --- Mystic JT8 144 420 -20 1.7 .15 Red Line 152 503 -49 --- --- 5W-50 Castrol Syntec 180 437 -45 1.2 .10 .095 % Phosphor Quaker State Syn. 173 457 -76 --- --- Pennzoil Performax 176 --- -69 --- --- 5W-40 Havoline 170 450 -40 1.4 --- 15W-40 AMSOIL 135 460 -38 <.5 --- Castrol 134 415 -15 1.3 .14 Chevron Delo 400 136 421 -27 1.0 --- Exxon XD3 --- 417 -11 .9 .14 Exxon XD3 Extra 135 399 -11 .95 .13 Kendall GT-1 135 410 -25 1.0 .16 Mystic JT8 142 440 -20 1.7 .15 Red Line 149 495 -40 --- --- Shell Rotella w/XLA 146 410 -25 1.0 .13 Valvoline All Fleet 140 --- -10 1.0 .15 Valvoline Turbo 140 420 -10 .99 .13 10W-30 AMSOIL 142 480 -70 <.5 --- Castrol GTX 140 415 -33 .85 .12 Chevron Supreme 150 401 -26 .96 .11 Exxon Superflo Hi Perf 135 392 -22 .70 .11 Exxon Superflo Supreme 133 400 -31 .85 .13 Havoline Formula 3 139 430 -30 1.0 --- Kendall GT-1 139 390 -25 1.0 .16 Mobil 1 160 450 -65 --- --- Pennzoil PLZ Turbo 140 410 -27 1.0 --- Quaker State 156 410 -30 .9 --- Red Line 139 475 -40 --- --- Shell Fire and Ice 155 410 -35 .9 .12 Shell Super 2000 155 410 -35 1.0 .13 Shell Truck Guard 155 405 -35 1.0 .15 Spectro Golden M.G. 175 405 -40 --- --- Unocal Super 153 428 -33 .92 .12 Valvoline All Climate 130 410 -26 1.0 .11 Valvoline Turbo 135 410 -26 .99 .13 Valvoline Race 130 410 -26 1.2 .20 Valvoline Synthetic 140 450 -40 <1.5 .12 5W-30 AMSOIL 168 480 -76 <.5 --- Castrol GTX 156 400 -35 .80 .12 Chevron Supreme 202? 354 -46 .96 .11 Chevron Supreme Synt. 165 446 -72 1.1 .12 Exxon Superflow HP 148 392 -22 .70 .11 Havoline Formula 3 158 420 -40 1.0 --- Mobil 1 165 445 -65 --- --- Mystic JT8 161 390 -25 .95 .1 Quaker State 165 405 -35 .9 --- Red Line 151 455 -49 --- --- Shell Fire and Ice 167 405 -35 .9 .12 Unocal 151 414 -33 .81 .12 Valvoline All Climate 135 405 -40 1.0 .11 Valvoline Turbo 158 405 -40 .99 .13 Valvoline Synthetic 160 435 -40 <1.5 .12 All of the oils above meet current SG/CD ratings and all vehicle manufacture's warranty requirements in the proper viscosity. All are "good enough", but those with the better numbers are icing on the cake. The synthetics offer the only truly significant differences, due to their superior high temperature oxidation resistance, high film strength, very low tendency to form deposits, stable viscosity base, and low temperature flow characteristics. Synthetics are superior lubricants compared to traditional petroleum oils. You will have to decide if their high cost is justified in your application. The extended oil drain intervals given by the vehicle manufacturers (typically 7500 miles) and synthetic oil companies (up to 25,000 miles) are for what is called normal service. Normal service is defined as the engine at normal operating temperature, at highway speeds, and in a dust free environment. Stop and go, city driving, trips of less than 10 miles, or extreme heat or cold puts the oil change interval into the severe service category, which is 3000 miles for most vehicles. Synthetics can be run two to three times the mileage of petroleum oils with no problems. They do not react to combustion and combustion by-products to the extent that the dead dinosaur juice does. The longer drain intervals possible help take the bite out of the higher cost of the synthetics. If your car or bike is still under warranty you will have to stick to the recommended drain intervals. These are set for petroleum oils and the manufacturers make no official allowance for the use of synthetics. Oil additives should not be used. The oil companies have gone to great lengths to develop an additive package that meets the vehicle's requirements. Some of these additives are synergistic, that is the effect of two additives together is greater than the effect of each acting separately. If you add anything to the oil you may upset this balance and prevent the oil from performing to specification. The numbers above are not, by any means, all there is to determining what makes a top quality oil. The exact base stock used, the type, quality, and quantity of additives used are very important. The given data combined with the manufacturer's claims, your personal experience, and the reputation of the oil among others who use it should help you make an informed choice.

The following article is intended to help you make a choice based on more than the advertising hype.
Oil companies provide data on their oils most often referred to as "typical inspection data". This is an average of the actual physical and a few common chemical properties of their oils. This information is available to the public through their distributors or by writing or calling the company directly. I have compiled a list of the most popular, premium oils so that a ready comparison can be made. If your favorite oil is not on the list get the data from the distributor and use what I have as a data base.
This article is going to look at six of the most important properties of a motor oil readily available to the public: viscosity, viscosity index (VI), flash point, pour point, % sulfated ash, and % zinc.

Viscosity is a measure of the "flowability" of an oil. More specifically, it is the property of an oil to develop and maintain a certain amount of shearing stress dependent on flow, and then to offer continued resistance to flow. Thicker oils generally have a higher viscosity, and thinner oils a lower viscosity. This is the most important property for an engine. An oil with too low a viscosity can shear and loose film strength at high temperatures. An oil with too high a viscosity may not pump to the proper parts at low temperatures and the film may tear at high rpm.
The weights given on oils are arbitrary numbers assigned by the S.A.E. (Society of Automotive Engineers). These numbers correspond to "real" viscosity, as measured by several accepted techniques. These measurements are taken at specific temperatures. Oils that fall into a certain range are designated 5, 10, 20, 30, 40, 50 by the S.A.E. The W means the oil meets specifications for viscosity at 0 F and is therefore suitable for Winter use.
The following chart shows the relationship of "real" viscosity to their S.A.E. assigned numbers. The relationship of gear oils to engine oils is also shown.
_______________________________________________________________
| |
| SAE Gear Viscosity Number |
| ________________________________________________________ |
| |75W |80W |85W| 90 | 140 | |
| |____|_____|___|______________|________________________| |
| |
| SAE Crank Case Viscosity Number |
| ____________________________ |
| |10| 20 | 30 | 40 | 50 | |
| |__|_____|____|_____|______| |
______________________________________________________________
2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42
viscosity cSt @ 100 degrees C

Multi viscosity oils work like this: Polymers are added to a light base (5W, 10W, 20W), which prevent the oil from thinning as much as it warms up. At cold temperatures the polymers are coiled up and allow the oil to flow as their low numbers indicate. As the oil warms up the polymers begin to unwind into long chains that prevent the oil from thinning as much as it normally would. The result is that at 100 degrees C the oil has thinned only as much as the higher viscosity number indicates. Another way of looking at multi-vis oils is to think of a 20W-50 as a 20 weight oil that will not thin more than a 50 weight would when hot.
Multi viscosity oils are one of the great improvements in oils, but they should be chosen wisely. Always use a multi grade with the narrowest span of viscosity that is appropriate for the temperatures you are going to encounter. In the winter base your decision on the lowest temperature you will encounter, in the summer, the highest temperature you expect. The polymers can shear and burn forming deposits that can cause ring sticking and other problems. 10W-40 and 5W-30 require a lot of polymers (synthetics excluded) to achieve that range. This has caused problems in diesel engines, but fewer polymers are better for all engines. The wide viscosity range oils, in general, are more prone to viscosity and thermal breakdown due to the high polymer content. It is the oil that lubricates, not the additives. Oils that can do their job with the fewest additives are the best.
Very few manufactures recommend 10W-40 any more, and some threaten to void warranties if it is used. It was not included in this article for that reason. 20W-50 is the same 30 point spread, but because it starts with a heavier base it requires less viscosity index improvers (polymers) to do the job. AMSOIL can formulate their 10W-30 and 15W-40 with no viscosity index improvers but uses some in the 10W-40 and 5W-30. Mobil 1 uses no viscosity improvers in their 5W-30, and I assume the new 10W-30. Follow your manufacturer's recommendations as to which weights are appropriate for your vehicle.

Viscosity Index is an empirical number indicating the rate of change in viscosity of an oil within a given temperature range. Higher numbers indicate a low change, lower numbers indicate a relatively large change. The higher the number the better. This is one major property of an oil that keeps your bearings happy. These numbers can only be compared within a viscosity range. It is not an indication of how well the oil resists thermal breakdown.

Flash point is the temperature at which an oil gives off vapors that can be ignited with a flame held over the oil. The lower the flash point the greater tendency for the oil to suffer vaporization loss at high temperatures and to burn off on hot cylinder walls and pistons. The flash point can be an indicator of the quality of the base stock used. The higher the flash point the better. 400 F is the minimum to prevent possible high consumption. Flash point is in degrees F.

Pour point is 5 degrees F above the point at which a chilled oil shows no movement at the surface for 5 seconds when inclined. This measurement is especially important for oils used in the winter. A borderline pumping temperature is given by some manufacturers. This is the temperature at which the oil will pump and maintain adequate oil pressure. This was not given by a lot of the manufacturers, but seems to be about 20 degrees F above the pour point. The lower the pour point the better. Pour point is in degrees F.

% sulfated ash is how much solid material is left when the oil burns. A high ash content will tend to form more sludge and deposits in the engine. Low ash content also seems to promote long valve life. Look for oils with a low ash content.

% zinc is the amount of zinc used as an extreme pressure, anti- wear additive. The zinc is only used when there is actual metal to metal contact in the engine. Hopefully the oil will do its job and this will rarely occur, but if it does, the zinc compounds react with the metal to prevent scuffing and wear. A level of .11% is enough to protect an automobile engine for the extended oil drain interval, under normal use. Those of you with high revving, air cooled motorcycles or turbo charged cars or bikes might want to look at the oils with the higher zinc content. More doesn't give you better protection, it gives you longer protection if the rate of metal to metal contact is abnormally high. High zinc content can lead to deposit formation and plug fouling.

The Data:
Listed alphabetically --- indicates the data was not available
Brand VI Flash Pour %ash %zinc

20W-50
AMSOIL 136 482 -38 <.5 ---
Castrol GTX 122 440 -15 .85 .12
Exxon High Perfor. 119 419 -13 .70 .11
Havoline Formula 3 125 465 -30 1.0 ---
Kendall GT-1 129 390 -25 1.0 .16
Pennzoil GT Perf. 120 460 -10 .9 ---
Quaker State Dlx. 155 430 -25 .9 ---
Red Line 150 503 -49 --- ---
Shell Truck Guard 130 450 -15 1.0 .15
Spectro Golden 4 174 440 -35 --- .15
Spectro Golden M.G. 174 440 -35 --- .13
Unocal 121 432 -11 .74 .12
Valvoline All Climate 125 430 -10 1.0 .11
Valvoline Turbo 140 440 -10 .99 .13
Valvoline Race 140 425 -10 1.2 .20
Valvoline Synthetic 146 465 -40 <1.5 .12

20W-40
Castrol Multi-Grade 110 440 -15 .85 .12
Quaker State 121 415 -15 .9 ---

15W-50
Chevron 204 415 -18 .96 .11
Mobil 1 170 470 -55 --- ---
Mystic JT8 144 420 -20 1.7 .15
Red Line 152 503 -49 --- ---

5W-50
Castrol Syntec 180 437 -45 1.2 .10 .095 % Phosphor
Quaker State Syn. 173 457 -76 --- ---
Pennzoil Performax 176 --- -69 --- ---

5W-40
Havoline 170 450 -40 1.4 ---

15W-40
AMSOIL 135 460 -38 <.5 ---
Castrol 134 415 -15 1.3 .14
Chevron Delo 400 136 421 -27 1.0 ---
Exxon XD3 --- 417 -11 .9 .14
Exxon XD3 Extra 135 399 -11 .95 .13
Kendall GT-1 135 410 -25 1.0 .16
Mystic JT8 142 440 -20 1.7 .15
Red Line 149 495 -40 --- ---
Shell Rotella w/XLA 146 410 -25 1.0 .13
Valvoline All Fleet 140 --- -10 1.0 .15
Valvoline Turbo 140 420 -10 .99 .13

10W-30
AMSOIL 142 480 -70 <.5 ---
Castrol GTX 140 415 -33 .85 .12
Chevron Supreme 150 401 -26 .96 .11
Exxon Superflo Hi Perf 135 392 -22 .70 .11
Exxon Superflo Supreme 133 400 -31 .85 .13
Havoline Formula 3 139 430 -30 1.0 ---
Kendall GT-1 139 390 -25 1.0 .16
Mobil 1 160 450 -65 --- ---
Pennzoil PLZ Turbo 140 410 -27 1.0 ---
Quaker State 156 410 -30 .9 ---
Red Line 139 475 -40 --- ---
Shell Fire and Ice 155 410 -35 .9 .12
Shell Super 2000 155 410 -35 1.0 .13
Shell Truck Guard 155 405 -35 1.0 .15
Spectro Golden M.G. 175 405 -40 --- ---
Unocal Super 153 428 -33 .92 .12
Valvoline All Climate 130 410 -26 1.0 .11
Valvoline Turbo 135 410 -26 .99 .13
Valvoline Race 130 410 -26 1.2 .20
Valvoline Synthetic 140 450 -40 <1.5 .12

5W-30
AMSOIL 168 480 -76 <.5 ---
Castrol GTX 156 400 -35 .80 .12
Chevron Supreme 202? 354 -46 .96 .11
Chevron Supreme Synt. 165 446 -72 1.1 .12
Exxon Superflow HP 148 392 -22 .70 .11
Havoline Formula 3 158 420 -40 1.0 ---
Mobil 1 165 445 -65 --- ---
Mystic JT8 161 390 -25 .95 .1
Quaker State 165 405 -35 .9 ---
Red Line 151 455 -49 --- ---
Shell Fire and Ice 167 405 -35 .9 .12
Unocal 151 414 -33 .81 .12
Valvoline All Climate 135 405 -40 1.0 .11
Valvoline Turbo 158 405 -40 .99 .13
Valvoline Synthetic 160 435 -40 <1.5 .12

All of the oils above meet current SG/CD ratings and all vehicle manufacture's warranty requirements in the proper viscosity. All are "good enough", but those with the better numbers are icing on the cake.

The synthetics offer the only truly significant differences, due to their superior high temperature oxidation resistance, high film strength, very low tendency to form deposits, stable viscosity base, and low temperature flow characteristics. Synthetics are superior lubricants compared to traditional petroleum oils. You will have to decide if their high cost is justified in your application.
The extended oil drain intervals given by the vehicle manufacturers (typically 7500 miles) and synthetic oil companies (up to 25,000 miles) are for what is called normal service. Normal service is defined as the engine at normal operating temperature, at highway speeds, and in a dust free environment. Stop and go, city driving, trips of less than 10 miles, or extreme heat or cold puts the oil change interval into the severe service category, which is 3000 miles for most vehicles. Synthetics can be run two to three times the mileage of petroleum oils with no problems. They do not react to combustion and combustion by-products to the extent that the dead dinosaur juice does. The longer drain intervals possible help take the bite out of the higher cost of the synthetics. If your car or bike is still under warranty you will have to stick to the recommended drain intervals. These are set for petroleum oils and the manufacturers make no official allowance for the use of synthetics.

Oil additives should not be used. The oil companies have gone to great lengths to develop an additive package that meets the vehicle's requirements. Some of these additives are synergistic, that is the effect of two additives together is greater than the effect of each acting separately. If you add anything to the oil you may upset this balance and prevent the oil from performing to specification.

The numbers above are not, by any means, all there is to determining what makes a top quality oil. The exact base stock used, the type, quality, and quantity of additives used are very important. The given data combined with the manufacturer's claims, your personal experience, and the reputation of the oil among others who use it should help you make an informed choice.

Concluzia ar fi ca dacia ne obliga sa bagam in motorase ulei slab (10W-40). Sau ma insel?

Si mie imi e cam neclar cum stau lucrurile.... Ciudat articol... O fi stiind cel care a scris asta mai multe decat mine. Asta nu inseamna ca stie adevarul absolut... Trebuie sa tinem cont si de clima temperat - continentala care e in Romania, cu geruri si calduri mari. De aia s-a ales 10W40. Nu prea am inteles din articol de ce 5W40 e bun si 10W40 nu.....

Uleiul 10W40 nu e un ulei slab! Nu stiu cine v-a bagat in cap asemenea ineptie dar minca ce nu trebuie! BMW, Mercedes, Opel, Audi/VW, Volvo... toate astea folosesc pentru anumite motoare uleiul cu indicativul 10W40, difera doar producatorul utilizat/recomandat..... Daca era ulei prost, credeti ca-l mai baga cineva in motoare?

pai ia ca poate aflu si io atunci care-i faza cu 20w40 la berlina, ca io d'asta am bagat 24 de ani in berlina veche si n-a avut nici pe dreaq
si in asta noua tot 20w40 am bagat,
e bine, nu-i ?!?!?

La asta noua bagi 15W40 (injectie) sau 20W50 (carburatie)

a, ups
am bagat 20w40 si e injectie...
ce are???
sa-l skimb acu' (am facut vreo 1200km) sau la urmatorul skimb
io oricum am o regula, si indiferent de ulei nu trec de 3000-3500 cu el

Pai iarna oricum e logic sa-i pui indicele mic cat mai mic (adica 15W in loc de 20W)... Diferenta e doar la pornire, pana se dezmorteste, nu?

Lasa-l pina data viitoare...
Ce ulei bagi de mergi doar 3500 (max) cu el ? Eu iarna il schimbam la 2000 dar era RO3. Elf-ul il schimb la 5 mii.

io oricum am garaj in bloc si e cald in garaj (18-20 de grade) kiar si cand sunt -15 grade afara

Intrebare: Uleiul are a face cu motorul sau cu injectie/carburatie?

Ca dupa capul meu daca motorul e la fel, il doare in cocoasa ca amestecul ii vine dintr-un carburator sau dintr-un injector. Daca stiu eu bine, motorul la berlinele cu carburatie (ultimele) si cele cu injectie e acelasi.

s-ar putea sa aiba, ca astea pe injectie merg pe apa fara plumb si cica-se ar fi temperatura un pic mai mare.... nu shtu, zic si io

Asha dar de 15 w 40(sau 45) ce ziceti?! Mie asha imi recomanda in service(carburatie), e mai bun decat 20 w 40 sau 20 w 50?
Faza e ca nu am priceput mare lucru din articolul ala.... :roll: .

...w50 e mai bun vara, ca ramane mai vascos

Mie articolul ala imi trezeste niste suspiciuni. Poate ne dai si sursa.
Din cunostintele mele (umile) si ca sa fac un rezumat.
Vascozitatea SAE: prima cifra indica vascozitatea la rece. Fiecare valoare reprezinta o clasa de produs, de ex. 20W inseamna ca mai curge inca la -10 grade C (daca mai tin bine minte valorile), 15W mai curge la -15; 10W la -20; 5W la -25, etc. Deci daca vrem sa mergem iarna, trebuie sa alegem un ulei care sa fie bun pana la cea mai scazuta temperatura preconizata. Un alt avantaj al uleiurilor cu prima cifra mica este timpul scurt pana la ajungerea acestuia in toate cotloanele motorului. Valoara de dupa W indica vascozitatea la cald (la o temp. stas considerata de regim termic normal). Aici nu sfatuiesc pe nimeni sa bage altceva decat ce e recomandat de producatorul masinii. La motoarele foarte uzate, "meseriashii" mai baga ulei mai gros (indice mai mare) in speranta micsorarii consumului de ulei. Cine isi mai aduce aminde de pe vremea lu' ceashca, pentru dacie era recomandat 20W40 vara si 10W30 iarna, ca sa se apropie cat mai mult de ideal. Pe vremea aia in ro nu era 10W40. Eu am acum si in dacie ('74) si in Oltcit 5W40 si nu papa ulei nici una.

Afara de vascozitate, noi ne mai putem uita la indicativul API. Codurile api sunt formate din literele S si C urmate de cate o alta litera. S se refera la benzina, C la siesel. Cu cat litera de dupa S respectiv C e mai spre coada alfabetului, cu atat uleiul e mai performant, de generatie mai noua. Respectati intotdeauna indicele minim (in cazul fericit in care ce scrie pe bidon e si inauntru). Motoarele moderne pe benzina au nevoie de MINIM SG sau SH.

Ar mai fi un indcator de urmarit, desi e mai rar scris pe bidoanele vandute in romania, si anume clasificarea ACEA. Aceasta poate fi A1, A2, A3 si mai nou A4 (daca retin bine) pentru benzina si respectiv B1, B2, B3 si B4 pentru diesel. Si aici valoarea mai mare inseamna calitate mai buna a uleiului.

Referitor la baza uleiului, in ziua de azi nu se mai considera ca acceptabile decat uleiurile sintetice sau macar semisintetice. Am avut ocazia sa vad rezultatele unor teste facute pe uleiuri din cele 3 mari clase, si nu va spun decat ca in timp ce uleiul mineral se innegrise si nu mai curgea din pahar, cel sintetic parea ca nici nu fusese atins.

Uleiul pus de constructori in motoarele noi este de obicei un ulei de rodaj, de multe ori e chiar 15W40 si e aditivat special.

Recomandarea mea este sa mergeti pe cat posibil cu 5W40 de la o firma de incredere si nu veti avea probleme. Atentie ca unele masini au personalitate, adica iubesc o marca de ulei mai mult ca alta. De exemplu cu ulei 5W40 de la firma X consuma ~150 g/1000 km, iar cu aceeasi clasa de ulei de la Y, consumul scadea la sub 50 g/ 1000 km. Nu am explicatie logica.

Uleiul 10W40 nu e un ulei slab! Nu stiu cine v-a bagat in cap asemenea ineptie dar minca ce nu trebuie! BMW, Mercedes, Opel, Audi/VW, Volvo... toate astea folosesc pentru anumite motoare uleiul cu indicativul 10W40, difera doar producatorul utilizat/recomandat..... Daca era ulei prost, credeti ca-l mai baga cineva in motoare?

Pai in articolul postat se spunea clar ca 10W-40 e slab.

RazvanD,

Poate ne dai si sursa

poate la....
http://www.micapeak.com/info/oiled.html

Si niste lucruri interesante la
http://www.bmcno.org/techtip_motor_oil.htm

BMW, Mercedes, Opel, Audi/VW, Volvo... toate astea folosesc pentru anumite motoare uleiul cu indicativul 10W40

Poate ne dai si sursa UNDE ai vazut ca acesti producatori recomanda asa ceva... Nu de alta, dar in al doilea link al lui Klaus se spune CLAR ca daca pui asa ceva in motor iti pierzi garantia!!!

Foarte interesant. Sa intelegem deci ca dacia renault sunt in urma cu informatiile despre uleiuri? Si ca ne obliga sa punem in motoare ulei care nu e la fel de bun ca unul de un alt tip? Toate articolele astea m-au pus in ceata.

Dacia te obliga sa bagi in motor un ulei de o calitate minima, cat sa stea ei linistiti ca nu se strica masina in garantie. Exista printre romani si "exemplare" care cred ca Ro3 e la fel cu altele de firma (idem cu anvelopele montana). Nu dau nume de firme .

Nu stiu daca are cineva experienta, dar cine are probleme cu ungerea motorului, poate sa incerce Metabond. Eu folosesc Metabond din 1997 in masina mea (veche de 23 ani!), si sunt satisfacut cu rezulatatele obtinute.
Cine vrea sa afle mai mult poate sa incerce la www.metabond.ro sau la www.metabond.de. Aceste produse sunt fabricate in Gemania, si au proprietatea (printre altele) de a reduce frecarea cu pana la 25%.

Reduce frecarea.......
Iar incepeti fratilor cu DuraLube, metabond, Slick, alte alea rusesti, americane, congoleze....
In curand o sa apara margarina Delma cu gust de ulei 10W40 care reduce frecarea...

.... cu gust de capsunica sau piersicuta, pentru placerea copiilor!

Inca un site interesant despre uleiuri:
http://www.bobistheoilguy.com/

This post has been edited by cristimm: 12 Mar 2009, 12:31