CNG and LPG sequential kits may use a similar electronic idea—metering gaseous fuel through injectors—but they handle fuels stored in different states and at very different pressures. Their tanks, valves, pressure-control components and calibrations are therefore fuel-specific.
This guide explains product and selection principles. It does not confirm compatibility, replace model-specific documents or provide a repair procedure.
CNG and LPG sequential kits compared
| What to compare | CNG sequential kit | LPG sequential kit |
|---|---|---|
| Fuel in the tank | Stored as a high-pressure gas. | Stored as a pressurised liquid. |
| Pressure control | A CNG reducer lowers gas pressure before fuel is metered to the engine. | An LPG vaporiser reduces pressure and converts liquid fuel to vapour before metering. |
| Fuel delivery and calibration | A dedicated ECU and injectors meter CNG using settings matched to the engine and fitted components. | A dedicated ECU and injectors meter LPG using settings matched to the engine and fitted components. |
| Vehicle approval check | Use the CNG approval list for the relevant emission category, make, model and engine capacity. | Use the LPG approval list for the relevant emission category, make, model and engine capacity. |
The cylinder or tank, valves and filling arrangements are fuel-specific. Injector characteristics, pressure targets and calibration maps also differ.
CNG and LPG components should not be mixed unless the specific system documentation explicitly provides for it.
Choosing between the fuels
Consider local fuel availability, vehicle application, storage space, approved conversion options and competent after-sales support. Real-world cost and efficiency vary by vehicle and route, so compare current local data without assuming one fuel will always be cheaper or more economical.
Check the approval list for the fuel you choose
Select CNG or LPG, then the vehicle’s emission category and make. Match both the model name and engine capacity in cc. A CNG listing does not establish LPG coverage, or vice versa. Confirm the exact engine, variant, model year and current approval documents before installation.