Mix rating of trailer tires?

[Lund79]

First off I want to say I have looked at this site awhile before signing up and there is a wealth of knowledge.

Here's my scenario. I have a '79 Lund 15' boat and I want to replace the tires on the trailer with new ones. I already have 2 new tires that I was going to replace but noticed 1 is a B rating and 1 is a C rating tire. Currently the tires on the trailer are C rating and was going to use these as a spare. The furthest I have to travel is 1 hour.

The reason I want to change tires is I bought it a few years ago and not sure the age of the tires so I thought I would put new on for peace of mind. I do have the option of returning the 1 new C rating back but would like to run the 4 ply vs 2 ply.

Am I going to have problems if I mix the tires? If I can do this, do I inflate the tires to the max per tire rating (50 PSI for the B, 75 PSI for the C) or do I lower the C rating to match the B rating of 50 PSI?

Thanks for any and all advice.

[Jim Uran]

Hopefully someone chimes in because their are a ton of knowledgeable people on here like you said.

If it were me, I'd throw them on and see how they pull, but I live in the country and would have no worries testing it out.

[Northlander]

Always run the same type tires.

[Dave S]

Always run the same type tires.

Absolutely correct. The higher load rating will eventually cause premature wear on the other tire. The last thing you need while going down the road is a blowout while doing 65-70 down the interstate.

[Valv]

Keep the C rating and return the B rating, don't even use it as spare. The more plies you have the more load the tire will support and the safer you will travel

[Lund79]

Thanks for the feedback. I figured I would be better off running the same ply but wanted thoughts if this situation be a big no no.