603Country said:
Not in any way suggesting that you are wrong, but you have to admit that it is interesting that I have gotten so many different opinions on the best or most correct operating pressure when towing or not towing.
Not at all surprising. Your Michelin "techs" are most likely customer service reps looking at a matrix graph, trying to come up with something for an answer. As for a lot of answers I read in many threads, its keyboard cowboys who know everything, about everything. In reality, they know very little and throw out something they hope will stick or regurgitate something they've seen elsewhere. If someone isn't intimately knowledgeable of the subject, I wish they'd just refrain from posting, as it only adds confusion and further misinformation.
First off, the doorjamb sticker is an average suggestion, trying to cover many scenarios. It's not perfect and not set in stone. Case in point is my truck, which shows 35F/35R. My frontend is substantially heavier than the rear. Therefore, I wouldn't need as much pressure in the rear to support its weight, since it's lighter. Likewise, if I follow the sticker and go load 1000lbs of material in the bed, now, I'm underinflated for the load. But, wait!!! The sticker tells me blah, blah, blah. We need to be inflated for the actual load and not what a sticker or sidewall says.
Now, I presume, you left Discount Tire in the same truck you drove in. The only thing you changed was a bit larger tire, which adds a bit more tire volume, which means you can run a bit less pressure (1-2psi). However, for some reason, you feel the need to run 50psi in them. I don't understand why. You've changed nothing about the weight of your truck, so there wouldn't be any need to drastically increase your pressures beyond factory, because you're not supporting additional weight. If anything, take advantage of the extra volume/flotation of them and drop a few. It's a 10-ply tire and will already ride rougher than what came on it. A 6- or 8-ply tire could've handled what you're going to be towing. But, I understand wanting to be equipped. No worries, there. You would only need to bump up the rears, once you're loaded or hitched. Lastly, an overinflated tire will have less grip than one properly inflated for the weight being carried.
As I stated above, your TT doesn't have a massive tongue weight. If I could suggest anything, it would be a nice, automatic ride-height airbag system and a WD hitch. The airbags will keep the truck at a set height and desired attitude, your TT at a desired attitude, and help to stabilize the rig. A WD hitch will further the stabilization and help mitigate porpoising. I have both and have never had an issue with any trailer configuration or weight.
Do not add 10psi extra to any tire, for peace of mind (I'll save the essay). However, a TPMS would be great to monitor pressure gain. When you see pressure in a tire creeping up beyond what the others are sitting at (assuming all are equally loaded), you'll know you're having an issue at that location. Likewise, if you see more than 10-15% pressure gain across similarly loaded tires, you'll know you need to bump pressures to better support the weight. If you're at max psi on the sidewall, you'll need to investigate heavier tire options. Overspeeding, bad wheel bearings, bent axles, poor alignments, etc do not count.
The Suburban mentioned above has the factory presuming it's going to be carrying passengers in the rear, so they purposely suggest a much higher pressure in the rear to support their weight. I only mention this, so people don't automatically assume they need to be running the same level of pressures, in the same positions, in their empty or dissimilar vehicles. That thing is a heavy beast, ready to haul everyone and pull anything.