Gasoline or petrol as an engine lubricator

Ever wonder why my installer advised me to let the car spend overnight over petrol, now I know the answer. It's because the nature of gas.

Technically, CNG engines are not that different from gasoline or diesel ones.

“There’s a little bit of modification because the fuel is dry, being a gas,” said Dan Masood, an instructor in alternative fuels at the New England Institute of Technology.

“It’s not a liquid so it hasn’t the lubricating qualities like gasoline and diesel.” Differences include hardened valves and a higher compression ratio because of the 130 octane level, he said.

CNG is about 95 percent methane, which burns very efficiently.

McClanaghan said it was far cleaner than other petroleum-based fuels, even clean diesel. “You open up an engine [after thousands of miles] and it’s perfectly clean,” she said.

“CNG is one of the simplest hydrocarbons,” said Masood.

The combustion process basically produces carbon dioxode, but about 40 percent less of it than gasoline, and water.

Some of the nitrogen from the air used in combustion is turned into nitrogen oxide, or Nox, but if the cylinders are kept below a certain temperature much of the nitrogen comes out unaffected, he said.

More from Projo

Tags: gas, cng, liquid, cleaner combustion, engine, nitrogen