CARPILLS AT A GLANCE:

• Compact, solid fuel-additive tablets
• No liquid to measure or pour
• 12 tablets per tube
• One tablet treats up to 40 litres, following the dosing instructions
• One-off purchase or a choice of subscription schedules
• Diesel fuel-analysis report available to read

WHAT DRIVERS NOTICED:

"We've been using car pills for about six months and we are very satisfied with them.

The fuel consumption has dropped by around 7%. And this is even though previously we were using premium diesel fuels about half the time at petrol stations. It also seems to us the engine produces less smoke than before.

We enjoy the ease of dosing the pills when fueling the car so we can only heartily recommend them."

Honza - Ford Mondeo, 2.0-litre diesel 

"I have first results after approx. 450 miles. The car runs substantially better, engine sounds smoother, valves don't knock and are quieter. The engine has a more refined operation overall and my impression is as if it is 3 to 4 years younger - runs smoother and noticeably quieter, almost as if it was new."