Part of the answer is that the Toyota thing came up after VW had committed the engine to the US market. Another part of the answer is German arrogance. They feel if it was designed correctly by them, then it will not fail. Any failures must be because of the ignorant people who drive the vehicles.
First, I would like to reference this post and AJA888s post that followed.
I am a VW loyalist to the core, but I was also a mechanic and dealer, so I have an acute sense of the "arrogance" problem. I clearly remember when pointing out a press bar error in training when negative roll radius geometry (negative KPI offset) was first introduced. Our instructor (straight off of the boat) drew himself up to full height, turned bright red and spit out: "Ve do not MAKE mischtaykes!"
I am in the oil industry now (both upstream and downstream) and one thing that would bother me as a person responsible for technical matters is at what point someone is claiming that gasoline cross contamination "must" have happened. Certainly, at the terminal there might be a TINY bit of gasoline in D2, but it will be insignificant. This is where the brand name stuff comes in. Any tank farm I see has dedicated tanks, but I can imagine that some of the little, old places might do some shuffling. Carriers are a very different deal. They range from extremely good to extremely bad. The oil I work with now is ultra-sensitive to contamination (as in down to the parts per BILLION range for surfactants) and 95% of off-spec problems are related to the carrier(s), so I can easily see the situation where a tanker compartment is gasoline one trip and diesel the next. The retailer, of course, is an entire crap shoot. BUT, even if the guy (incuding US) on the nozzle gets it right, there is no way of knowing if at some time in the life of the tank beneath you, a carrier didn't drop some gasoline in by mistake. I think back to the "gap" time when VW did not certify their diesels in the US market. IIRC, they could not even FIND any LSD at retail distribution points (what would be required to meet emissions at the time). Also, from a friend who sells the stuff by the tanker, a LOT of high sulphur D2 hits the US, and I am still not sure it all gets re-processed before it gets into the distribution system (should be much better now than 5 years ago). Why all of this complacency about cross-contamination? Diesels are truly multi-fuel engines, and really don't care that much what hydrocarbon is coming their way - from an operational standpoint.
BUT: that brings us to the next step along the way - the pump itself. I doubt very much that Bosch would be re-designing to reduce cost when there is already feedback of what I consider UN-ACCEPTABLE sensitivity to fuel quality. The merry men back in the Fatherland know that too, but this is where the arrogance thing comes in. They would NEVER admit to being wrong about anything - ever. It is just the culture. And, I am sorry to say, if we want the best quality engineering on the planet, it is just the cost of doing business. It has also been my experience that once caught red handed, the official response is very, very slow in coming, but the technical response MIGHT be fairly quick - and obviously very quiet. Does not excuse this problem. There is NO excuse for it to exist - or worse yet for VW/Bosch to try to back out of their responsibility. The only way to deal with a teutonic manufacturer is to take a 2x4 and whack him smartly up the side of the head to get his attention first. THEN you can start to LEAD a discussion. If you follow, you lose.
Just a side-note on additives: our eldest is a grad student researching the lubricity properties of Canola (rapeseed oil). Fantastic stuff, and available all over this region as a lubricity additive you can dump in at the pump. B5 may be in your station, but I don't think soy based bio is anywhere near the lubricity from canola based bio-D. One of the advantages of living in the middle of the GWN prairies.
