Actually, when we got the SF July last year, i've already read that it's compatible with BD5 in the manual (i love reading manuals). Yun nga lang, i haven't finished reading all of it (at least the center part). Read the back though. I usually read random front to center, back to center. Rarely front to back because i easily get bored.
Anyway, I've tried BD1 (it's so funny when i heard the gas boy that it's only 1%) in Biofuel center in Philcoa last December but haven't really noticed anything. Someone here said that 1% is enough but i can't verify nor refute that.
It makes me wonder why not BD20 or even BD80. How come only BD5.
WWFC guidelines only list Biodiesel to conform up to 5% blend (10% naman for ethanol). The reason for this is that current fuel engines cannot handle higher blends atm (fuel lines will wear off)......except yung mga flex-fuel vehicles.
Not to mention that you would need more raw material & arable land to create higher concentrations of biofuels without disrupting food supply.
So right now, WWFC guidelines list 5% for Biodiesel and 10% for ethanol.