biodiesel

Following BMW Malaysia announcing it found “technical challenges” running its diesel engines on B10 biodiesel (10% palm-based biodiesel/90% petroleum diesel blend, will reportedly be implemented nationwide by October), and that its engines can take up to B7, Mercedes-Benz Malaysia, UMW Toyota and Volkswagen Malaysia have issued responses that echo the same sentiments.

UPDATE: Isuzu has released a statement regarding the unsuitability of B10 for its engines.

Mercedes-Benz Malaysia says its diesel-powered passenger cars, vans and trucks can use up to B7 biodiesel (7% palm-based biodiesel/93% petroleum diesel blend), while Fuso trucks in Malaysia can only take a maximum of B5 biodiesel (5% palm-based biodiesel/95% petroleum diesel blend). It goes on to say that “the introduction of B10 biodiesel requires further consideration.”

Responding to our questions, UMW Toyota said its current diesel engines are not rated for B10 use; they can only take up to B7. As such, they do not encourage B10 use in their models. It’s the same story with Volkswagen Malaysia, who told us that running B10 on its diesel engines will produce adverse effects as well as void the warranty.

diesel-cap

Also not in support of B10 is Isuzu Malaysia, which says that one of the primary concerns about biodiesels of grades B7 and above has been, among others, the high presence of water in the blends of palm methyl ester. Biodiesel is hydroscopic in nature and tends to absorb water from the atmosphere, which can cause deposit formation, microbial growth and degradation of fuel quality, ultimately affecting the vehicle’s engine operation and durability.

In view of this, Isuzu says that the current limit of water content in biodiesel is acceptable up to grade B7, and that further conclusive tests will need to be conducted and proven with consistent results to allow for levels B7 onwards.

So far, only BMW Malaysia has gone to town with the issue, technically elaborating on the problems it found during testing, including oil thinning leading to sludge, reduced lubricity, injector deposit formation, injector invariance, reduced idling cycle stability and higher levels of water in the fuel leading to component corrosion.

BMW Malaysia even brought our attention to a 2012 joint-statement by diesel injector makers Delphi, Denso, Bosch, Continental and Stanadyne, which cited reduced fuel stability (leading to “plugged filters, sediments and sticking moving parts”), impurities in the fuel and compatibility issues with older vehicles (most likely affecting filters, hoses and seals) with biofuels.