How do you improve emissions from your car?

Hi Cyril,

There are a few advertised ‘trick' fuel additives such as STP or Dipetane that promise to reduce the emissions from the engine, but these are at best unproven and at worst utter snake oil. Your best bet is simply to get the car thoroughly serviced and tuned up and make sure it’s running on high-quality petrol or diesel bought from a reputable source.