A couple months ago when I began to explore our N scale truck offerings in more detail, I already knew that it was sparse, but there are a few bright spots if you look hard enough. Kato did us all a favor when they produced their Volvo tractor, for the modern modelers. I don't own anything but Kato locomotives, and have become accustomed to the incredible detail and crispness of their models. It wasn't until I began designing my own models for 3D printing that I found a fairly major shortcoming.
Illustrated below is a Kato Volvo tractor, an Atlas Ford 9000 tractor, and one of my own designed and printed set of rims and tires. Common wheel sizes for rigs today are 22.5" and 24.5", with a matching sized tire. I based my design off of an Alcoa 24.5" rim. I know that my tires are perfectly scaled to 1/160, since I drew them life size, and then scaled them down for printing. You can see that the Ford 9000 has a tall tire that is about right for that truck. It's the Volvo that makes me cringe. If you compare the out of the box rims and tires, they are dwarfed by my version. I have taken a close look at the Volvo to see if I could get my set of tires under the fender wells, but I don't think there is enough room. Oh well, I guess I can look past this flaw, but it is pretty obvious when hitched to a trailer with appropriately scaled tires.
We do have plenty of "not quite right" models in our scale, but I would rather have the model with its flaws than no model at all. That is what I am learning with 3D printing. It isn't perfect, but brings models into existence that in the past we only prayed and hoped some N scale manufacturer would produce for us. Now I can personally do something about these model voids.