# What is the cetane index of diesel?

## What is the cetane index of diesel?

The cetane index is a figure which denotes the quality of a diesel fuel, based upon its density and volatility, and which is roughly approximate to its cetane number. It is loosely linked to the octane number of gasoline, since both give a measure of each substance’s efficacy and are inversely related.

### What is a good cetane index?

The scale for measuring cetane ranges from 0 to 100, and the higher the number, the better. 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.

What is the difference between cetane number and cetane index?

Cetane number is the most important and universally accepted ignition quality test. 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.

How do you calculate diesel index?

A7: Diesel index is an indication of the ignition quality of a diesel fuel. It can be determined by calculation from the specific gravity and the aniline point of the sample Diesel index = (Aniline point * °API) / 100.

## How is cetane index calculated?

The cetane index is calculated based on the fuel’s density and distillation range (ASTM D86). There are two methods used, ASTM D976 and D4737. The older D976, or “two-variable equation” is outdated and should no longer be used for cetane number estimation.

### What is the best density of diesel?

about 0.85 kg/l
The density of petroleum diesel is about 0.85 kg/l – about 15–20% higher than the density of gasoline, which has a density of approximately 0.70–0.75 kg/l.

How do you calculate cetane index?

How much is too much cetane?

As such, a cetane improver is not needed because the fuel itself already contains an adequate amount of cetane. If you increase the cetane number too high (55 and beyond), it can deteriorate the fuel and actually cause a reduction in overall engine performance.