Cifra octanica-importanta

[cristimm]

Al meu merge si cu mai putin <_<.

 

Poate nu am ales cifrele corect dar oricum ideea e aceeasi.

Edited January 29, 2009 by cristimm

[Rhaziel]

1. bun, benzina de 100 e mai rezistenta la comprimare, deci se aprinde cand crede ECU ca e necesar!

2. benzina de 95 e mai putin rezistenta la comprimare deci e posibil sa se aprinda inainte de a da ECU scanteia prin bujie, determinand ECU sa recalculeze timpii de aprindere.

 

asadar, teoretic, benzina de 100 se aprinde la un moment de comprimare mai mare decat cea de 95, deci si "deflagratia" este mai puternica......corect? intrebarea mea este: e sanatoasa treaba asta pentru supape?

[cristimm]

asadar, teoretic, benzina de 100 se aprinde la un moment de comprimare mai mare decat cea de 95, deci si "deflagratia" este mai puternica......corect? intrebarea mea este: e sanatoasa treaba asta pentru supape?

 

Nu, nu e corect. Daca un motor a fost conceput sa mearga cu benzina de 95 atunci nu poate FIZIC sa comprime mai mult pentru a putea beneficia de cifra octanica mai mare.

[Ciupanezu]

ĂnsĂŁ este bine sĂŁ foloseÂşti benzinĂŁ cu cifrĂŁ octanicĂŁ mai mare pentru cĂŁ acestea au ĂŽn general un conĂžinut mai mic de sulf.

[Bavaria]

ĂnsĂŁ este bine sĂŁ foloseÂşti benzinĂŁ cu cifrĂŁ octanicĂŁ mai mare pentru cĂŁ acestea au ĂŽn general un conĂžinut mai mic de sulf.

 

Exista vreo legatura intre cifra octanica si sulf?Serios?

[Ciupanezu]

Nu direct.

 

ĂnsĂŁ am vĂŁzut cĂŁ, cel puĂžin la Petrom, 99+ conĂžine mai puĂžin sulf decât Petrom 95.

[Emiliannec]

M-am uitat cu ocazia asta pe situl celor de Petrom si am observat ca ambele tipuri de benzina atat Premium 95 cat si Top Premium 99+ au continut scazut de sulfuri..diferenta intre acestea este data la alte capitole (de exemplu se comporta mai bine motorul la accelerari si decelerari cu Top Premium 99+). Fiecare pune cum considera ca e mai potrivit. <_<

 

Info Benzina Petrom!

[BMarius]

http://www.carbibles.com/fuel_engine_bible_pg2.html

 

Extras:

 

Octane and power

 

It's a common misconception amongst car enthusiasts that higher octane = more power. This is simply not true. The myth arose because of sportier vehicles requiring higher octane fuels. Without understanding why, a certain section of the car subculture decided that this was because higher octane petrol meant higher power.

The reality of the situation is a little different. Power is limited by the maximum amount of fuel-air mixture that can be jammed into the combustion chamber. Because high performance engines operate with high compression ratios they are more likely to suffer from detonation and so to compensate, they need a higher octane fuel to control the burn. So yes, sports cars do need high octane fuel, but it's not because the octane rating is somehow giving more power. It's because it's required because the engine develops more power because of its design.

There is a direct correlation between the compression ratio of an engine and its fuel octane requirements. The following table is a rough guide to octane values per engine compression ratio for a carburettor engine without engine management. For modern fuel-injected cars with advanced engine management systems, these values are lowered by about 5 to 7 points.

Compression ratio -> Octane

5:1 -> 72

6:1 -> 81

7:1 -> 87

8:1 -> 92

9:1 -> 96

10:1 -> 100

11:1 -> 104

12:1 -> 108

 

Octane and gas mileage

 

Here's a good question : can octane affect gas mileage. The short answer is absolutely, yes it can, but not for the reasons you might think. The octane value of a fuel itself has nothing to do with how much potential energy the fuel has, or how cleanly or efficiently it burns. All it does is control the burn. However, if you're running with a petrol that isn't the octane rating recommended for your car, you could lose gas mileage. Why? Lets say your manufacturers handbook recommends that you run 87 octane fuel in your car but you fill it with 85 instead, trying to save some money on filling up. Your car will still work just fine because the engine management system will be detecting knock and retarding the ignition timing to compensate. And that's the key. By changing the ignition timing, you could be losing efficiency in the engine, which could translate into worse gas mileage. Again as a practical example, my little tale above about our trip to Vegas on low octane gas. (Whether you want to believe some bloke on the internet or not is up to you). On the low octane gas on the trip down, we could barely get 23.5mpg out of the Subaru. Once I was able to fill it up again with premium at the recommended octane rating, we got 27.9mpg on the way back. A difference of 4.4mpg over 450 miles of driving.

Doing the maths, you can figure out that by skimping on the price during fill-up, you may save a little money right there and then, but it costs in the long term because you're going to be filling up more often to do the same mileage. My advice? Do what the handbook tells you. After all it's in the manufacturers better interests that you get the most performance out of your car as you can - they don't want you badmouthing them, and in this day and age of instant internet gratification, you can bad-mouth a large company very quickly and get a lot of publicity.

 

 

Fara rea intentie va zic sa cititi cam tot ce e pe carbibles.com, nu veti afla decat lucruri interesante si, zic eu, reprezinta bagajul minim de cunostinte care ar trebui sa-l aiba orice persoana care se vrea "pasionat" de masini.

 

Spor!

Edited February 4, 2009 by BMarius

[treitreizero]

mie asta imi place:

 

http://www.molromania.ro/ro/produse/carburanti/benzina_evo/

[Rhaziel]

stiam de la un mecanic, de la un service Yamaha, ca nu e foarte sanatos la motoare stock sa pui benzina cu cifra octanica mai mare decat media! adica daca producatorul recomanda 95-98 nu e sanatos deloc sa pui 100, pentru ca, citez "arde supapele"... omul se ocupa numai cu motoare de turatie si putere foarte mare, jetski-uri, etc si de aceea ma gandeam ca stie ce vorbeste.... dar probabil e altceva cand e vorba de motoare BMW...

[ricko]

stiam de la un mecanic, de la un service Yamaha, ca nu e foarte sanatos la motoare stock sa pui benzina cu cifra octanica mai mare decat media! adica daca producatorul recomanda 95-98 nu e sanatos deloc sa pui 100, pentru ca, citez "arde supapele"... omul se ocupa numai cu motoare de turatie si putere foarte mare, jetski-uri, etc si de aceea ma gandeam ca stie ce vorbeste.... dar probabil e altceva cand e vorba de motoare BMW...

benzina indigena de 100 are cam 98 de fapt...

[Bavaria]

stiam de la un mecanic, de la un service Yamaha, ca nu e foarte sanatos la motoare stock sa pui benzina cu cifra octanica mai mare decat media! adica daca producatorul recomanda 95-98 nu e sanatos deloc sa pui 100, pentru ca, citez "arde supapele"... omul se ocupa numai cu motoare de turatie si putere foarte mare, jetski-uri, etc si de aceea ma gandeam ca stie ce vorbeste.... dar probabil e altceva cand e vorba de motoare BMW...

 

Nu e altceva, e la fel.

[Ciupanezu]

Ăntrebarea este: de unde cumperi benzinĂŁ de 100 ĂŽn România? <_<

[andrei27]

M-am uitat cu ocazia asta pe situl celor de Petrom si am observat ca ambele tipuri de benzina atat Premium 95 cat si Top Premium 99+ au continut scazut de sulfuri..diferenta intre acestea este data la alte capitole (de exemplu se comporta mai bine motorul la accelerari si decelerari cu Top Premium 99+). Fiecare pune cum considera ca e mai potrivit. <_<

 

Info Benzina Petrom!!!

 

Da, si pe site-ul Lukoil, spun ca benzina obtinuta prin rafinare la rafinaria Petrotel are tot 50 ppm de sulf, exact ca si la Petrom ( www.lukoil.ro/ Dati click pe rafinaria Petrotel in top-stanga).

 

Cineva spunea pe acest topic (sau altul ?) acum ceva vreme ca benzina de la Lukoil e rea pt ca are continut ridicat de sulf, deci era fals.

Edited February 8, 2009 by andrei27

[LordBMW]

Salutare again la toata lumea...am citit mai sus din ceea ce s a vb si revin..la ora asta am un seria 5 din 1993 masina pe care din momentul in care am luat o si pana in prezent cred eu ca am intretinut o , mai putin cu uleiul ca i am pus mobil 1 :)( si am inteles ca nu e bun deloc...tot pe aici am citit chestia cu ""eticheta"" peste ""eticheta"" si din nefericire a avut DREPTATE ...turcia...in fine ideea este ca in ultima perioada imi cam vibreaza in relantiu si parca nu lucreaza toate pistoanele, uneori imi porneste f greu...(mentionez am lasat o 2 luni si ceva pe dreapta), din ce mi s a zis s ar putea sa am probleme cu un senzor care nu i baga destul oxigen..are cineva vreo idee in ceea ce priveste acest aspect? o alta varianta este imfluenta combustibilului...bine raspunsul poate fi concludent...la tester, dar a avut cineva aceasta problema vreodata? ms anticipat.. <_<

[alex230ro]

http://www.carbibles.com/fuel_engine_bible_pg2.html

 

Extras:

 

Octane and power

 

It's a common misconception amongst car enthusiasts that higher octane = more power. This is simply not true. The myth arose because of sportier vehicles requiring higher octane fuels. Without understanding why, a certain section of the car subculture decided that this was because higher octane petrol meant higher power.

The reality of the situation is a little different. Power is limited by the maximum amount of fuel-air mixture that can be jammed into the combustion chamber. Because high performance engines operate with high compression ratios they are more likely to suffer from detonation and so to compensate, they need a higher octane fuel to control the burn. So yes, sports cars do need high octane fuel, but it's not because the octane rating is somehow giving more power. It's because it's required because the engine develops more power because of its design.

There is a direct correlation between the compression ratio of an engine and its fuel octane requirements. The following table is a rough guide to octane values per engine compression ratio for a carburettor engine without engine management. For modern fuel-injected cars with advanced engine management systems, these values are lowered by about 5 to 7 points.

Compression ratio -> Octane

5:1 -> 72

6:1 -> 81

7:1 -> 87

8:1 -> 92

9:1 -> 96

10:1 -> 100

11:1 -> 104

12:1 -> 108

 

Octane and gas mileage

 

Here's a good question : can octane affect gas mileage. The short answer is absolutely, yes it can, but not for the reasons you might think. The octane value of a fuel itself has nothing to do with how much potential energy the fuel has, or how cleanly or efficiently it burns. All it does is control the burn. However, if you're running with a petrol that isn't the octane rating recommended for your car, you could lose gas mileage. Why? Lets say your manufacturers handbook recommends that you run 87 octane fuel in your car but you fill it with 85 instead, trying to save some money on filling up. Your car will still work just fine because the engine management system will be detecting knock and retarding the ignition timing to compensate. And that's the key. By changing the ignition timing, you could be losing efficiency in the engine, which could translate into worse gas mileage. Again as a practical example, my little tale above about our trip to Vegas on low octane gas. (Whether you want to believe some bloke on the internet or not is up to you). On the low octane gas on the trip down, we could barely get 23.5mpg out of the Subaru. Once I was able to fill it up again with premium at the recommended octane rating, we got 27.9mpg on the way back. A difference of 4.4mpg over 450 miles of driving.

Doing the maths, you can figure out that by skimping on the price during fill-up, you may save a little money right there and then, but it costs in the long term because you're going to be filling up more often to do the same mileage. My advice? Do what the handbook tells you. After all it's in the manufacturers better interests that you get the most performance out of your car as you can - they don't want you badmouthing them, and in this day and age of instant internet gratification, you can bad-mouth a large company very quickly and get a lot of publicity.

 

 

Fara rea intentie va zic sa cititi cam tot ce e pe carbibles.com, nu veti afla decat lucruri interesante si, zic eu, reprezinta bagajul minim de cunostinte care ar trebui sa-l aiba orice persoana care se vrea "pasionat" de masini.

 

Spor!

 

hmm

http://www.e46fanatics.com/faq/m54engine.html

 

pare-se ca pentru M54 trebuie benzina de 100?ma rog daca luam in considerare si ce zice acolo ca ar mai trebui scazuta cu cateva puncte rezulta 95-100?

[ricko]

Mobil 1, daca este original, este un ulei foarte bun.

[LordBMW]

de acord cu tine dar made in turkey?

[chriss]

Pai stai un pic.. La ce crezi ca se referea cand a spus "daca este original"? <_<

[LordBMW]

Si asta e drept...in fine sper sa ne mai ridicam si noi cu timpul in calitatea produselor si a serviciilor..