P tires vs LT tires - tire sales conflicting info

I changed my P tires to the same size except to a load range E on my 2013 F150 EcoBoost. Even got a 50K warranty. Haven't noticed any change in the ride. Made by Falken, Rocky Mountain model. Still a comfortable, smooth ride and the ability handle my TT. Wasn't prepared to like the 18" tires, but all seems well so far. JMHO Maybe rated for 87 mph, but I don't run that fast usually. Only been to 95 mph running MT. No drama to date.