FAQs

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 Velvex 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, Velvex SAE 40 API CF may be used; old trucks change the oil in 8000-10000 kms usually.

Depending on the manufacturers recommendation, 16000-18000 kms

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.

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.

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 Velvex Zoom Premium 4T 20W-40. It is not advisable to use Velvex Zoom 4T 10W-30 in these motorcycles and also in old motorcycles where the clutch plates are semi worn out; the strong lubricity of Velvex Zoom 4T 10W-30 can cause clutch to slip leading to overheating.

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.

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

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.

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.

Less than normal oil level in the sump

Oil has become very thick and the flow has reduced considerably

Pressure guage not working

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

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.

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.

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.

This indicates the burning of engine oil; it will be accompanied by burning smell of oil in the exhaust. See also FAQ 13

It means poor combustion because of poor injection but is more commonly observed with blocked air filters.

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

Low power.