Octane
A gasoline's octane number is a measure of its ability to resist knocking as it burns in the combustion chamber of an engine. A spark from the spark plug starts normal combustion. The flame travels across the combustion chamber rapidly and smoothly until all the fuel is consumed. Abnormal combustion occurs when part of the fuel/air mixture ignites spontaneously and burns very rapidly, causing the pressure to rise suddenly. This results in a metallic knocking or pinging sound. A gasoline's ability to resist knocking is called its anti-knock quality. The octane number of a gasoline indicates the anti-knock quality of the fuel. A gasoline's octane number is determined by comparing its resistance to knocking to the performance of reference fuels in a test engine
Cetane
The cetane number is one of the most commonly cited indicators of diesel fuel quality. It measures the readiness of the fuel to auto ignite when injected into the engine. It is generally dependent on the composition of the fuel and can impact the engine’s start ability, noise level, and exhaust emissions.
In short, the higher the cetane number the more easily the fuel will combust in a compression setting (such as a diesel engine). The characteristic diesel "knock" occurs when the first portion of fuel that has been injected into the cylinder suddenly ignites after an initial delay. Minimizing this delay results in less unburned fuel in the cylinder at the beginning and less intense knock. Therefore higher-cetane fuel usually causes an engine to run more smoothly and quietly. This does not necessarily translate into greater efficiency, although it may in certain engines.
Typical values
Generally, diesel engines operate well with a CN from 40 to 55. Fuels with higher cetane number have shorter ignition delays, providing more time for the fuel combustion process to be completed. Hence, higher speed diesel engines operate more effectively with higher cetane number fuels.In Europe, diesel cetane numbers were set at a minimum of 38 in 1994 and 40 in 2000. The current standard for diesel sold in European Union, Iceland, Norway and Switzerland is set in EN 590, with a minimum cetane index of 46 and a minimum cetane number of 51. Premium diesel fuel can have a cetane number as high as 60.[2]
In North America, most states adopt ASTM D975 as their diesel fuel standard and the minimum cetane number is set at 40, with typical values in the 42-45 range. Premium diesels may or may not have higher cetane, depending on the supplier. Premium diesel often use additives to improve CN and lubricity, detergents to clean the fuel injectors and minimize carbon deposits, water dispersants, and other additives depending on geographical and seasonal needs.[citation needed]. California diesel fuel has a minimum cetane of 53.[3]
CETANE Ratings in Canada
Claim to EXCEED the minimum requirements:
45 - 52 Petro Canada
45 - 50 Sunoco Gold
45 - ?? Shell V-Power
45 - 50+ Autogas/Cascadia Biofuels (British Columbia)
42 - 45 Husky's DieselMax
41 - 43.5 Red River Co-op Co-op EP3000 Summer cetane is 46.5, winter is 44.0.
Fuel Polishing
How does fuel polishing affect fuel values?
Cleaning the fuel removes the impurities and improves the combustability of fuel.
After fuel polishing the Cetane and Octane levels will be much higher than before polishing.
Test Pricing – With fuel polishing ………………….$ 150.00 per test + gst
Cetane/Octane Test with labour …………………….$ 600.00 + gst ( This includes obtaining the sample on site)
CAll Us At 1 888 713 1090 to discuss Cetane or Octane testing on your site.
