CNG vs Gasoline

CNG Car Conversion vs. Gasoline Fuel 

Many people want to know the long term effects of CNG on a car’s engine. Or they want to know the differences in CNG fuel and regular gasoline or diesel. Below we address these questions and help illustrate there is not really a downside to a CNG car conversion.

Long Term Effects of CNG on Your Car’s Engine

The only drawback with CNG performance is a slight 5% (or thereabout) decrease in engine power. And if you’re saving 50% of fuel costs then who cares, right?

The life of an engine increases by using CNG. Lubricating oil life is extended considerably because CNG does not contaminate and dilute the crankcase oil. Another aspect, which increases engine life, is that CNG enters the engine in the form of a gas whereas gasoline or diesel enters in the form of spray or mist. This spray/mist washes down the lubricating oil from the piston ring area thereby increases the rate of depreciation of the engine.

Since this is not the case when using CNG, the life of the engine increased. On the whole, the maintenance costs are reduced and engine life is increased. The widespread use of CNG in Europe and Asia will support this fact.

CNG provides easy starting, reliable idling and smooth acceleration. When your vehicle is running on CNG, you may notice its acceleration to be a bit slower which is due to a power loss of typically 5% (really not even noticeable unless hooked up to a machine), which can be minimized by proper tuning on the CNG kit (done upon install and then annually with the ODBII software included in my SkyCNG kits) to take advantage of the high octane rating of the fuel. CNG has a Research Octane Number (RON) of 130. The power loss on CNG is generally not noticeable in ordinary city driving. CNG has a good mixture distribution quality. When the correct proportions are brought together they mix thoroughly and rapidly, which improves the combustion efficiency of the engine.

Some people say the CNG can burn your engine valves since it burns hotter, but as long as calibrated/tuned/mixed correctly (done electronically with the SkyCNG ECU computer) this will not happen any sooner than with gasoline. The Research Octane Number of CNG is 130 as compared to 87 or 93 premium motor gasoline. When CNG fuel is used, no carbon is formed during combustion and engine stays very clean internally.