I don't know all that much about tires, just a basic understanding from customer feedback and personal experience.
My last truck had "E" rates tires (Ext.Cab, Short Bed F-150) and it rode pretty rough / bumpy down the road.
The truck I have now (Ext. Cab, Long Bed F-150) has "D" rates tires and it seems to ride a bit smoother. But that might just be because it is a different truck and suspension ?
A co-worker here bought a new 2006 Tundra last year and we looked at the stock tires that came on it. The tread looked good at first glance, but if you looked at the specs, they were cheap tires. The treadwear rating was really low, the speed & temperature ratings seems low too (B ratings).
It seems like the better tires have the "A" ratings for that stuff (speed & temperature).
I like the idea of having the stiffer side walls and upgraded tires when carrying a camper on the truck. I think it will also help take some of the tire sway when driving with a heavy load.
It seems like the "E" rated tires are over kill when you are just looking at putting a small FWC pop-up on the truck.
If you were going to put a full cab-over camper on the truck (Six-Pac, Lance, Bigfoot, Alpinelite, etc.) I would highly recommend the "E" rated tires.
But for a small pop-up camper, you have a bit more wiggle room.
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