For the last thirty five years, we had a diesel tank at home and bought our DERV direct from local fuel suppliers (all of whom get their fuel via the Dalston, Cumbria rail point from the Grangemouth refinery). From what our suppliers told us, it was mainly Texaco diesel. For all that time, and in various vehicles, we never had a fuel problem. Now we've downsized and there's no more diesel tank.....the current vehicles are a 330D BMW and a brand new Amarok truck, and it's off to the supermarket for fuel nowadays. Have we seen a difference?? Short answer....yes! After 40-odd years in the oil industry, and being a Grumpy Old Engineer, I'm about to sneak into the local Tesco and put a tenner's worth in the tank, but also put a sample amount in a jar and send it off to some contacts for a full fuel test and cetane rating....
Both vehicles showed DPF warnings within six months. Admittedly, level of use was less, but a DPF warning in a brand new truck? Anyhow, treated the 330D with a diesel booster/system cleaner, and switched the Amarok over to premium diesel - end of problem.
Not as scientific an approach as I'd like, I'd be the first to admit. However, from years in the oil business I know that 'lifed out' aviation fuel (it's hygroscopic, so has a limited tank life) is typically re-sold to the fuel industry and then mixed into vehicle fuel to get rid of it, and also to adjust RON/Cetane levels, so it is fair to say that not all fuels are supplied to the end user at an identical standard. It is also true to say that the fuel manufacturing industry are tightly standardised and policed (especially in UK), but beyond those guys are 'fuel dealers' (somebody mentioned 'suppliers' from sunny Rotterdam...), and from experience buying marine diesel in many countries (especially Africa!!) the simple truth is that not all fuels are equal.
If I get any revelations from my Tesco test, I'll post them.