i was told by a factory rep that b5 is the limit for these common rail setups (not just international) because bio is "hard to control" (regarding ingredients and water content). rather than deal with it they set the limit super safe at 5%.
that is exactly the point. there is no quality control or ASTM test for water concentration, free methanol or unreacted lye for BioD.
i have seen VW pistons that were totally scorched and even melted due to running too high a concentration of bio. the fault was an injector malfuntion caused by the 'caustic' nature of the fuel, which essentially over fueled and melted the pistons in those cylinders. it takes seeing to believe and understand WHY. and remember, i IS an engineer.
and poke around the fuel and lube forums to see why you really don;t need more than B2 on these engines for lubricity benifits.
dp
