This also creates a situation where someone will reasonably fill up their vehicle before or after every use, which may be a balance mechanic to limit the use of veghicles, but ends up creating instead a situation where entry level mechanics do not get roadside assistance calls that could lead to very interesting RP (such as selling out the location of a vulnerable character, or just making connections and establishing ones self).
I believe the best solution for this is looking at every vehicle and not only giving it enough fuel to reasonably go a week of regular (but not necessarily extensive) use between fill-ups, but also to differentiate fuel capacities more distinctly between different chassis within the same name, to add tangible value to the larger badge numbers.