Is it okay to use fuel additives?

Over the years I've used Miller's Diesel Plus in our diesel cars, mainly to lubricate the injector pump rather than seeking extra performance. We have just bought a Kia Cee'd 1.6 CRDi, and the handbook warns of invalidating the warranty if additives are added to the fuel. Also, I was spotted at our local Shell filling station using the Miller's additive, and was told that V-Power already had the same ingredients. Is putting in the Miller's a waste of time? I still worry about lubrication of the pump and its longevity.
If using V-Power then you are not invalidating the KIA warranty and are getting enough lubricity.
Answered by Honest John on

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