My local car bits shop, General Traffic, in St Helens, is a superb down to earth place with rock bottom prices and staff who eff this and eff that all day. Brilliant! Now then. They have a new poster up, advertising "Dipetane". It promises to save you "up to" 10% on fuel costs, which is obviously meaningless as "up to" can also include "zero".

To be fair the manager of the shop said, he's had no-one in saying "that stuff is brilliant" and he himself remained a sceptic. I took a leaflet away and it seems very badly worded, in fact I have formed an opinion that would probably not get past the moderators here. The website is easy to find. If you see the site you might see what I mean, it looks like something you would need if you towed CARAVANS a lot.