Things grow in bio-diesel? First I have heard of that. I doubt that is true, and even if it were, it would not happen in your engine. Between the tank and the engine is a filter that is so fine that it blocks all but the most minute of particles. And then there is between the filter and the engine there is really no place for anything to grow. Do not
base your decisions on some stupid person’s silly claim. Instead, base your decision on facts that you research yourself.
Decide on what pickup you would buy, then research the engines, compare torque, fuel mileage and reliability
reports. Note, torque is important because that is needed to haul the load.
Then you can make a good decision