The mileage performance of 3 types of fuels on 2 types of vehicles is being studied. The engineer can only take at most 4 runs each day, and want to conduct the experiment within 2 weeks.If necessary, The engineer is ableto work 7 days a week during this period.

I need help with figuring out the design of this experiment. Ignoring the last sentence, I would say it is a 2 factor factorial with A=types of fuels with 3 levels, B=car type having 2 levels, and (6)4 = 24 total runs (randomly run).

I am confused on if the the constraint of the 2 weeks changes the design. And does the 7 days a week even matter?