The tag axle not only supports additional weight and gives the RV better carrying and towing capacity, it also improves ride and handling. The downside is that if you go through a toll booth towing a car you will be a five axle vehicle and will be charged the same as a tractor-trailer. Ouch. The tag only adds 2 extra tires so if you have to spend an extra $1000 every 7 years for tires that's really not a big deal. You will like having a tag axle for all the good things it provides.