None of that has anything to do with carbon emissions, which do not increase with poor maintenance (unlike NOx or particulates). And they're all manageable issues, unlike the carbon emissions of petrol engines.
However any mass adoption to biofuels would require different engine (existing engines will work fine on a low blend of biofuels, but very few will work on 10P%). For cars, why would you stick with a biodiesel engine which is more complicated and has higher levels of other pollutants, than some sort of biogasoline engine?
Hemp oil powering diesels is possibly the most efficient locomotion path we have, only really competing with electricity generated with little carbon emissions.