You can choose to convert your vehicle to run on pure gas with a spark ignition, using an approved conversion.
If your vehicle is registered in Great Britain, you'll need to register the conversion with the DVLA and obtain a certificate from the Vehicle and Operator Services Agency (VOSA). Please be aware that vehicles converted to run on bio-diesel don't meet the required emissions standards.
Fitting an approved filter to your exhaust could reduce your vehicle's emissions enough to meet the LEZ emissions standards.
You could upgrade to a newer vehicle that meets the standards or an electric vehicle, or you could convert to gas using an approved conversion.
If you operate a fleet of vehicles, you could reorganise it so that only vehicles meeting the emissions standards are driven within the zone.
We would prefer that your vehicle meets LEZ standards. However, if you're not able to take the measures needed, then you can pay the daily charge to drive within the zone.