red ex... does anyone use this for the fuel system? im in two minds

Pour a couple of bottles into the fuel tank and drive it until almost empty before refilling. I've used it a few times and it's never done any harm, whether it's done any good I don't know but my TD6 doesn't blow any smoke when given the lead boot

The Comma Diesel Magic/Petrol magic is better i've found, it's also cheaper.

I've used it on various cars, and it does seem to improve them, especially their idle quality. Of course it depends how dirty the cars fuel system is to start with. If it's been run on one of the Super Fuels (V-power etc) then chances are it will have a less noticeable effect as the fuel contains more detergents anyway.

I've used it and I can't detect any difference what so ever!!!
Ive tried v power r in our company van too which does a 1000 miles a week and I've not noticed any difference in that so I don't bother now.

On the petrol side I've tried v power in my jag and same deal - no difference!!!

I would like to think there is as its an expensive placebo !!!!

It just depends on how clean the injectors are to start with, if they're already clean then obviously it won't make any difference. I've used injection cleaner on cars that have had idling issues and rough running and a dose of it has done the trick. But obviously it will only help if a dirty fuel system is actually causing the fault.

As for the fuels, in terms of increased performance, different engines like different fuels. My jaguar for example wasn't noticeably different on v power but was a little more spritely and gave a couple of mpg more on BP ultimate. My classic mini showed no benefit from bp ultimate, but with v-power you'll get popping in the exhaust when decelerating, so that definitely runs differently. My mums Citroen diesel used to smoke on Tesco diesel but not on sainsburys diesel.

A van that's driven long distances day in day out will probably be pretty clean internally anyway. Whether any extra performance is worth the money is anyone's guess but it can only do good keeping the injectors clean.