I must be doing something wrong because I have checked all of the Ram Promaster 159" wheel base ones uploaded on 3D Warehouse and all are wrong when I measure the wheel base from the middle of the front wheel to the middle of the back wheel.
It’s hard to believe so many people spent this much time and screwed up the first most important thing that matters so I think I’m doing something wrong when I use my tape measure and do the measurement.
My measurement of this example here is 157.5 using tape measure
As that one comes in from the 3D Warehouse it’s pretty close. I rotated the front wheel so it is straight to get a more precise measurement.
Notice that Reset Scale is available in the Context menu while the group is selected. That indicates that the model was already scaled. Resetting the scale shows the wheelbase to be longer.
I guess you could adjust the scale to make the wheelbase 159 in.if you want. Keep in mind that most vehicles in the 3D Warehouse are modeled by hobbyists like yourself. Maybe they didn’t know how to make the wheelbase exactly 159 inches. Or maybe in reality it is supposed to be 158-3/8" and Dodge just calles it 159" That kind of thing isn’t unusual.
Also, when I search for “ProMaster cargo van” I see at least four models that appear essentially identical but supposedly by different authors. Likely only one of those guys actually modeled it (or got it from elsewhere and converted it to a SketchUp model) and the others downloaded it and then uploaded it as their own without changing the dimensions.
If you are going to use that model fix the incorrect tag/layer usage and the reversed faces first.
In addition to what @DaveR wrote, you need to make sure you are measuring from a spot on one wheel to the exactly equivalent spot on the other wheel. With the curved surfaces on those wheels it is very easy to miss. Going to monochrome style and view hidden geometry makes it easier. When I do that the values I get are quite close to 159".
thank you guys so much for your input! I’m going to get better at sketchup and end up doing my own model and I’ll upload that. I’ll pop back in here to link to it in case google finds this thread.