The following image shows how I went about doing this (I did this only for testing, it is a bit overkill I think…), but there is a simpler way…
*EDIT: I wrote this last night in a hurry and messed it up a bit, the following is what I meant to say
For each of my 4 axle bones, I right click (one at a time) and choose New Body, and in the popup change the “Collision Geometry” drop-down to a sphere (leave the rest as is) and press ok. This will create a basic physics asset for the tire.
Before moving on to the next wheel, in the image above you can see I changed the Physics type to be “Kinematic”, which all 4 tires need to be set at (But NOT on the root bone, just leave that).
The other thing that could be causing the issue is the tire diameter setting in your front and rear wheel blueprints. The best way is to measure the tire diameter in 3ds max (or whichever tool you use) and then set the tire diameter property in each of those blueprints.
If that still doesn’t fix it, make sure you follow the article below step by step, it will work in the end!!
Hope this helps, feel free to ask if you need to!