What are the functions of engine oil ?
Lubricate and prevent wear
Improve engine life
Clean the engine from combustion deposits
Protect against rust and corrosion from atmospheric and combustion moisture
What is a multi-grade engine oil and what are it’s benefits?
A multi-grade engine oil has special additives that allow it to have stable high temperature viscosity despite having low ambient temperature viscosity; the viscosity at 40 deg C is lower than that of a monograde SAE 40 oil enabling better flow during starting.
The multigrade oil has better starting ability.
What is API and SAE & what are their importance?
API is the American Petroleum Institute and SAE is the Society of Automotive Engineers; together, these international bodies define engine oil specifications for global standardization for new and existing models of vehicles. SAE defines the viscosity grades like 20W-40, 15W-40 & 5W-40 & API defines performance specifications like CF-4, CI-4, SL etc.
How do I select the correct oil for my car?
Modern cars in India like SX-4, Verna, Manza, Linea, Corolla, Camry, City etc may use Synthpower 5W-40, 5W-30 or 20W-50; these are suitable for petrol and diesel
The ILSAC GF-4 specification of Synthpower 5W-40 will ensure fuel saving benefits
For B Segment petrol cars like Swift, Santro, Indigo, Synthpower 20W-50 can be used.
Can the engine oil help in fuel economy in my car?
Low viscosity synthetic products like Synthpower 5W-40 and 5W-30 will provide about 2% and 3% fuel saving in normal driving conditions because their internal friction is very low and the lubrication efficiency is very high.
How do I select the correct oil for my commercial vehicle and what should be the ODI oil drain interval?
Modern BS 2 LCV & HCV trucks need to use minimum an API CF-4 product for engine protection; 15W-40 oil will protect the turbo shaft life by better cooling through fast flow of the oil; the OEMs have homologated engine oil ODI at 18,000 kms for highway service in HCVs
However, with the availability of API CH-4 oils available in the market, many fleets use API CH-4 even in BS 2 trucks. If a fleet has optimized the ODI at 18,000 kms using a CH-4 oil, the use of GT CI-4 Plus 15W-40 is possible till 36,000-40,000 kms ( same time filter change)
Modern BS 3 LCV & HCV vehicles should use minimum CH-4 engine oil for protection against engine soot and deposits. Tata Motors & Ashok Leyand have homologated BS 3 vehicles engine oil ODI at 36,000 kms for highway service.
Old BS 1 trucks and buses without turbocharger will benefit from the use of 20W-40 engine oil especially after 3,00,000 lakh kms.
For very old trucks using SAE 40 engine oil, SAE 40 API CF may be used; old trucks change the oil in 8000-10000 kms usually.
What is the change period of Super Power CF-4 20W-40?
Depending on the manufacturers recommendation, 16000-18000 kms
What is the important difference between diesel engine oil and petrol engine oil?
Diesel engine oil is designed to manage the higher soot produced in a diesel engine; a diesel engine oil can be used in a petrol engine but it is not advisable for a petrol engine oil to be used in diesel applications, unless it is low HP applications like 25 hp.
What is the benefit of using a 15W-40 oil for my turbo engine?
The fast flow of 15W-40 oil enhances turbo shaft cooling; the turbo shaft temperature can reach 500 deg C and fast cooling is important to prevent engine oil related carbon deposits on the turbo shaft which can lead to lower shaft rpm leading to lower turbo boost and poor engine performance.
How do I select the correct oil for my motorcycle or scooter?
New motorcycles in India are designed for JASO MA ( JASO MA covers MA-2) oils like 20W-40 & 10W-30; Zoom 4T SJ 10W-30 can be used in Hero Honda motorcycles which have 10W-30 recommendation.
100-125 cc motorcycles are better lubricated with Zoom Premium 4T 20W-40. It is not advisable to use Zoom 4T 10W-30 in these motorcycles and also in old motorcycles where the clutch plates are semi worn out; the strong lubricity of Zoom 4T 10W-30 can cause clutch to slip leading to overheating.
Why should I use only motorcycle oils for my two wheeler?
Please do not use an engine oil containing friction modifiers, the superior lubrication of these oil will cause clutch slippage in motorcycle wet clutch. In order to keep the motorcycle engine compact, the clutch is inside the engine-gear housing and is oil lubricated. Motorcycle oil must be JASO MA/ MA2 passed; JASO is the Japanese Automotive Standards Organisation.
Is it normal for engine oil to become black?
Yes, like a good soap, there is no problem if an engine oil becomes black very fast; sometimes, oils which are super loaded with detergents, can clean up the piston-liners very quickly; the engine oil stops functioning efficiently only when it becomes too thin or too thick
What causes excessive oil consumption?
High valve guide clearance will cause oil to travel from the head into the combustion chamber and get burnt
Oil sump gasket leaks
High oil level inside the sump can cause high splash into the combustion chamber
When the piston moves downward, it leaves behind on the cylinder wall some oil – during the power stroke, this oil gets burnt – so some oil consumption in all engines is normal; however, if the ring-liner clearance is high due to wear, the amount of oil getting burnt is more than normal
Similarly if the oil is very thin due to fuel dilution, more oil will escape into the combustion chamber and get burnt.
Why does fuel get diluted into the engine oil?
Improper injection in diesel engines
Continuous rich mixture in petrol engines
Some fuel coming into the oil is normal; however , it escapes out of the oil while the oil is operating at normal working temperature of 80-110 deg C; if the engine is continuously operating at low temperatures like below 70 deg C in winter months or because of a faulty radiator thermostat, fuel gets trapped inside the oil causing excessive thinning of the oil.
What are the reasons for low oil pressure?
Less than normal oil level in the sump
Oil has become very thick and the flow has reduced considerably
Pressure guage not working
What causes oil thickening?
If the soot in the engine is abnormal, the oil will become thicker faster than usual; improper combustion due to poor injection, blocked injectors or insufficient air due to blocked air filter can cause extra soot formation
Also, if the oil is getting highly oxidized because of very high temperature operation – continuous operation at 140 degC for 2000-3000 kms, the oil can become thick
I saw oil completely disappeared in my car/ motorcycle/ truck within 500 kms ? What is the reason for this?
This is a case of rapid oil consumption; the viscosity of diesel is 20 times less than engine oil; continual dilution or retention of fuel in engine oil will reduce oil viscosity to allow it to get burnt in the combustion chamber rapidly.
What may cause an engine to sieze?
Engine parts will begin to micro-fuse when the temperature of parts becomes higher than normal; this can be caused either because of lube starvation due to leakage, low oil level , high oil consumption or due to excessive oil temperature due to cooling failure. The temperature of the oil and parts increase to a point when ring-liner-piston can become joined leading to stoppage and increased engine damage.
When is white smoke observed in the exhaust and what does it mean?
The colour of smoke can provide excellent input to combustion quality. The exhaust colour of a well functioning diesel engine is colourless. White smoke being emanated briefly during engine startup is possible due to moisture condensation present in the tail pipe. But if the white smoke persists, then we are sure that either there is
A coolant leak into the engine oil because of head gasket failure or
There is raw unburned diesel in the exhaust due to injection malfunction; this will be accompanied by high fuel consumption and even back firing is possible.
When is blue smoke observed in the exhaust and what does it mean?
This indicates the burning of engine oil; it will be accompanied by burning smell of oil in the exhaust. See also FAQ 13
When is black smoke observed in the exhaust and what does it mean?
It means poor combustion because of poor injection but is more commonly observed with blocked air filters.
What are the harmful effects of poor fuel?
Injector wear and poor spray and poor combustion
Fuel dilution due to higher condensation on the liner if not fully burned; is observe in diesel and petrol