Blender .FBX to UE4 confusion. please help!

I want to make a car and I am totally capable of doing it, I know how to rig the vehicle and set up all the needed things in unreal. But when I export my own custom FBX object (in this case a vehicle) the scaling is all weird, let me explain

So when I put my custom car into UE4 and look in the physics asset the wheel radius on the sphere’s collision is 1.01 always

But when I exported the Sedan example vehicle from UE4 and put it into blender, exported it and looked in the physics asset the sphere radius was 34

Why is this?? The example Sedan from UE4 is smaller than the vehicle i’ve made but it somehow turns out correctly and works as intended. I have absolutely no clue what I am getting wrong when I rig my vehicle in blender. Please help me!

I don’t have a vehicle handy to test here but general rule of thumb is, in Blender set your scene units to metric and scale to 0.01. (this makes your Blender units into cm’s)

You may need to scale you vehicle up or down by 100 afterwards then remember, to apply the scale/rotation.

Then export as before. If you are using 4.15 when importing, make suer to tick the force x forwards tick box.