getDeltaRotation() on a sideways wheel

I have a vehicle that has 4 independently steered and powered wheels that need 360 degrees of steering, and I use a PhysicsTickListener along with getDeltaRotation to measure the rotational speed of each wheel. This works perfectly fine, except for when the wheels are pointed 90 degrees away from the standard forward direction. It seems to work at 45 degrees from forward, however I cannot tell if it is truly accurate or just measuring the forward component. Any Idea how to measure the rotation of a sideways wheel?

I compared the value of getDeltaRotation and vehicle.getLinearVelocity, and it seems that getDeltaRotation is only getting the component of rotation in the forward direction, how do i get the wheel’s angular velocity as a vector and not just the standard direction component?