## What do you mean by octane number and cetane number how they are related with IC engine?

Octane number shows the ability of a fuel to resist knock (pre-ignition of the fuel) in the Gasoline Engine that needs high compression ratios. the Cetane number is measures of ignition delay. Higher the cetane number of fuel the shorter the ignition delay, the least time it take to burn.

## How do you measure octane number?

The octane number is determined by comparing, under standard conditions, the knock intensity of the fuel with that of blends of two reference fuels: iso-octane, which resists knocking, and heptane, which knocks readily.

How is cetane number determined?

In the ASTM D613 test, the cetane number of a diesel fuel is determined by comparing its ignition delay in the standard CFR test engine with those for blends of reference fuels of known cetane number.

### What is octane number of diesel?

Modern highway diesel engines tend to require fuel with a cetane number ranging from 45 to 55. Typically, regular no. 2 diesel has a cetane number of 40 to 42, while Cenex® Premium Diesel has a cetane number of 47 to 52. LEARN MORE: Q&A: REGULAR VS. PREMIUM DIESEL.

### What is the difference between cetane number and cetane index?

The cetane number test uses a standard single cylinder variable compression ratio diesel engine. Cetane index is a calculated value, which is derived from relatively easily measured fuel properties. Thus, cetane index can provide a measure of fuel ignition quality without the need to run the costly cetane number test.

What do you mean by 91 octane fuel?

Octane rating is the measure of a fuel’s ability to resist “knocking” or “pinging” during combustion, caused by the air/fuel mixture detonating prematurely in the engine. In the U.S., unleaded gasoline typically has octane ratings of 87 (regular), 88–90 (midgrade), and 91–94 (premium).

#### What is the octane rating of diesel?

Examples

Fuel RON MON
n-octane −20 −17
n-heptane (RON and MON 0 by definition) 0 0
diesel fuel 15–25

#### What is the difference between diesel index and cetane number?

The diesel index usually gives values slightly above the cetane number. Composition Based Models. Composition-based models are more generally applicable than those based on distillation temperature and allow for the prediction of the cetane number of diesel fuels regardless of the refining process.

What is the difference between octane and diesel?

In way of energy, different octane ratings don’t make a difference, and it isn’t more efficient to put higher octane gasoline in your car than it requires. Diesel, on the other hand, is a different type of fuel and compared to standard gasoline it offers more energy per gallon.

## What is octane number of diesel in India?

In 2010, sulfur content was lowered to 150 ppm nationwide and 50 ppm in Bharat IV compliant cities. Under BS II, the octane number was increased to 88 and 93 for regular and premium, respectively. It was further increased to 91 and 95 for regular and premium, respectively, under BS III and beyond.

## What do you mean by octane rating?

Octane rating is a measure of a fuel’s ability to resist ‘knock. ‘ The octane requirement of an engine varies with compression ratio, geometrical and mechanical considerations, and operating conditions. The higher the octane number, the greater the fuel’s resistance to knocking or pinging during combustion.

What is the difference between octane and cetane?

Octane goes in your car’s fuel, but cetane goes in a diesel’s. Think of it like this: in a sense, cetane is the opposite of octane. If your fuel has a high cetane number, it will have a low octane number, and vice versa. A high cetane rating represents a fuel that can readily ignite and perform better in a diesel engine.

### What is the cetane rating of diesel fuel?

Cetane number or cetane rating is the performance indicator of the combustion speed of diesel. It is an inverse function of an octane number. High octane number fuel delays the ignition, but high cetane number fuel speed up the ignition.

### What is the octane number of fuel in gasoline fuel?

Commonly octane number of fuel ranges from 87 to 95 in gasoline fuel. Cetane rating is measured according to the ignition of the cetane. N-hexadecane consists maximum cetane number which is the hundred and 1-methylnaphthalene has minimum cetane number zero. It ranges from 30 to 35, fuel exceeding this number is known as poor fuel.

What is the octane number of n-hexadecane?

Commonly octane number of fuel ranges from 87 to 95 in gasoline fuel. Cetane rating is measured according to the ignition of the cetane. N-hexadecane consists maximum cetane number which is the hundred and 1-methylnaphthalene has minimum cetane number zero.