This might be a silly question, apologies if it is, but do you add diesel additives direct from the bottle into the fuel tank whilst putting some fuel into the car?

i take it you mean redex or similar. this is from my personal experiance of using redex for petrol cars.

i beleive with redex they advise you to get the fuel right down, go to a petrol station, empty the bottle into the fuel tank and fill the rest of the tank with fuel.

but if i read it correctly for diesel it says half the bottle.

in the end, its up to you though, you dont need to use additives if your using good quality fuel say from BP and Shell. this is because they already have their own mixed in. apparently if your a supermarket fuel user (morrisions/tesco/asda etc)then it will be a good idea to use redex etc, but like i say down to user.

oh and on a further note, make sure the redex or similar, is catalitic converter friendly etc.

hope this is helpfull

as JohnH said, you do put the bottle / half bottle into an empty tank and then top up the fuel to the click.

I use supermarket fuel but dont use redex regularly, perhaps once every 6 months, after the problem with my fuel filter, I am considering using it more, or getting a "proper" diesel additive offline...

millers is apparently spot on for having a good additive and far better than redex and other brands.

im currently using millers oil and have no complaints, the mpg has increased and engine noise has decreased. but then again i dont think my car has ever had someone give it a decent service!

but back to topic, if their oil is go by i would use their additive aswell

millers is apparently spot on for having a good additive and far better than redex and other brands.

im currently using millers oil and have no complaints, the mpg has increased and engine noise has decreased. but then again i dont think my car has ever had someone give it a decent service!

but back to topic, if their oil is go by i would use their additive aswell

+1 for Millers. It's called Millers Diesel Power Ecomax, in a 500ml bottle. I used it in my Focus which usually runs on Tesco diesel. I can't say I noticed much improvement in mpg, but it did make the car a little less smokey.