Gary,
95% of all my engines are run without rubber traction tires, and they run great, even with the add on Cars, the LC Santa Toy Maker express runs just fine, on all the different levels of our layout. I do not own any of the lighter LC Diesel Engines however. If I was Lionel, I would get rid of all the rubber traction tires, and engineer all the new LC+ Engines with Magna-Traction.
PCRR/Dave