They are much stronger tires- stiffer sidewalls designed to take heavy loads. Passenger tires have a lot of squishy in them.
A good experiment before you get new tires would be to air up your tires (when towing) to the max pressure on the tire and see if that makes a difference.
2014 Stealth Evo 2850 "Woodstock"
2011 Toyota Tundra Rock Crawler TRD 5.7 "Clifford"
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2014 Stealth Evo 2850- "Woodstock"
2011 Toyota Tundra Rock Crawler TRD 5.7- "Clifford"
2013 Honda Accord Coupe V6 w/Track Pack- "Julia"