First of all, you cannot nerf the trunk space of original vehicles like the car or the tank, just to say that your Truck carries more cargo. If this Truck is part of another mod, then just nerf it elsewhere. Otherwise it is quite annoying to realize that suddenly all valuable items in your trunk got disintegrated from one savegame to another just because of this mod.
Second, this Truck really drains a lot of fuel, and given the original Car and Truck trunk space, this Truck really does not compensate the cost-benefit of fuel consumption.
In other words, nice idea, but bad implemented.