Hi Peter, Years ago we had a long discussion on the M site on this subject. The conclusion was that going to radials was the better way to go. I used Goodyear Radials on my Trailrite trailer for our M15, and puts lots of miles on it, driving from Connecticut to Florida and back as well as shorter trips to Lake Champlain. I never had a problem either launching, or cruising down the Interstate at 70 MPH. The other M-listers probably agree with me as well. Connie ex M15 #400 LEPPO