No.

The Mk V 1.9 is fitted with a DPF. Neat biodiesel does not work properly with post injections because the flashpoint of the fuel is too high. You'll more than likely end up with a clogged DPF and a sump full of fuel. You might get away with it for mainly motorway use if you're really determined to press ahead.

But there's a reason that most 100% biodiesel conversions are in the heavy duty sector. They just don't have the regen problem.

There are always wild claims about the superiority of alternative fuels which raises the question of why they aren't mainstream!

Actually, I should have said boiling range rather than flashpoint in my previous post.

Biodiesel is partially oxidised (it contains oxygen in its molecular structure). This is why it burns with less soot. Unfortunately, it is also has a lower calorific value (less mileage) and why it has a tendency to form varnishes in the high pressure injection system.

Although Bio tends to create less soot than dino diesel, it does still create soot which must then be burned off from the DPF.

The problem with bio diesel and DPF is with post injection. The point of post injection is to spray fuel into the cylinder when the temperature in the cylinder is not sufficient to ignite it, but is sufficient to vaporise it. The gaseous diesel then passes through the oxidation catalyst, where it is burned. This raises the temperature of the gas entering the DPF to a sufficient level to oxidise the soot. Diesel has a lower boiling range than bio, but even so, post injections cannot take place at very low engine load.

If the cylinder temperatures are too low then the fuel spray will not vaporis but impinge on the cylinder bores and the rings will scrape it down into the sump.

This is why you see buses running on 100% bio. The engines work much harder than car engines so the cylinder temperatures are much higher so post injection is less of a problem.Even so, oil change intervals are invariably greatly reduced with bio.

If you mainly do motorway miles, it would make a great experiment. But keep a very close eye on your oil, checking frequently for fuel contamination.

Biodiesel does have a higher cetane rating than dino diesel, which is why a lot of people think it is 'better'. But unless you live in a cold climate, cetane rating definitely has a saturation point, where no further gains in engine performance are realised-other than a quieter idle.

Sorry for long post.