After 5 months of research for both engine and fuel considerations and with a spare fuel filter in the glovebox, I am running B20 SoyBioDiesel. Anecdotally the performance is slightly better, engine noise is quieter, torque on hills is stronger, fuel consumption is slightly less ~5% (maxidot) and exhaust odour and particulate is negligible.

In summary, my research tells me, to borrow a castrolism, "oils aint oils" and each 'biodiesel' product should be considered in isolation of all other 'like' product. Of particular interest to me was the VAG stipulation that Pumpe Düse (PD) injection engines have a potential issue and are not endorsed for biodiesel greater than B5 due to the high (30,000 psi) injector pressures compared to earlier diesels. The concern is that the high pressure pump/injection environment may cause diesel compound breakdown. Current common rail (CR) technology engines are running similar pressures on modern SoyDiesel and do so happily and are approved for biodiesel use by VAG. Skoda Australia blanket rules Biodiesel as unsuitable for all models.

My car is pre Diesel Particulate Filter (DPF) so avoids the 'blockage/burnoff' issue experienced by later models.

I have found a SoyBioDiesel manufacturer that has only a handful of contracted service stations across Sydney, none in my area yet. National Biodiesel Ltd has a 'private' bowser they pump to approved customers. It's the only fuel station I know of where I can drive away and pay later. Cost is $1.10 per litre including GST. Sydney Diesel prices by comparison are around $1.27 per litre.

I'll post when I change my first set of injectors, hopefully after 300,000km

Edited 25 August, 201015 yr by michaelp

Make sure you change your fuel filter after a couple of tanks of the fuel and then if you can afford it another 5k miles after that.

Bio can cause the crud that has built up in the fuel tank to come off and that will block up the fuel filter.

crikey, at that price i'd be running it round on proper diesel rather than cheapskating it....

the equivelent price here for diesel is about $2.20 aus dollar per litre...

interesting stuff though, i'm not sure how well the pd unit iinjectors will last out running on biofuel, i read somewhere about the seals being ruined by biofuels

After 2 tanks of B20 I bit the bullet and went to B100. 40,000 km later with routine maintenance intervals My Ocy hasn't looked back. Cleaner running and smelling, quieter engine, ~5% better economy than Mineral Diesel, reduced harmful emissions except NO2 doubled.

The cost is 4 cents less per litre than mineral diesel but for me its about the principle of not being Crude oil dependent and sustainable (only 20% of the soyabean is used in the cold press process, the rest is moved on for food production and other use) details here

Edited 18 March, 201115 yr by michaelp

guys

i ran a superb 130bhp (AWX code) on all sorts of bio mixs. the only modification i did was to insert a valve in the return line from the fuel filter. this stopped spent/excess hot fuel returning to the tank and therefore was used immediately with the benefit that it was hot fuel and flowed better that normal dinosaur deisel. throughout our winter months i used B30 available from our local supermarket.

in summer months i moved up to an equilavent B70 mix and at least once per week used B100. i had no issues at all but decided it was best to change the fuel filter every 10k miles

once i tried B100 in the winter and on starting the engine needed more cranking to start and then left her to idle for a few minutes. whilst warming up she did not like heavy acceleration so it was a case of take it easy. once warmed up to normal temp the old girl flew. i found exactly the benefits as you did.....quieter running, more torque etc etc.

that car served me well for four years and some 250k miles. no injector problems whatsoever and the new owner has gone a stage further by installing twin tanks. this allows starting on 100% dinosaur deisel and when up to normal running temp she is switched over to 100% bio. just before shutting bthe engine down she is switched over to 100% dinosaur fuel in readiness for the cold start next day. this proceedure is used 365 days a year.

the car is now almost 8yrs old and at 360k miles still running on original injectors and never once had a problem with the EGR valve etc.

sadly my modified superb mk2 is unable to run on bio other than whats in the pumps.....all diesel here is now EU compliant and has a minimum 5% bio added although in France etc its nearer 10% bio added and she runs fine.

enjoy your efforts with running on bio