I have had teflon strips in my '40 for 17yrs and 80k miles . The ride is smoother than without the teflon and I prefer it this way when driving without a load (most of the time) HOWEVER , the original shocks were not up to the task of damping the free movement and I have had to up grade the shocks.
Since adding the camper to the truck and subsequent E load range tyres and bigger rims , I feel the teflon is not so ideal under this loading situation.
