Trailer got 24.5 truck has 22.5

The size difference should not affect your mileage, your rolling resistance may.

 

Does your trailer run level?

 

Shouldn't affect your fuel.

It'll affect your brakes though.

Trailer drums spinning slower then truck drums.

I have the same dillema. Drives and drop axle are 22. All other tires are 24.

 

My truck has tall rubber(24.5) and my trailer is on 255/22.5.
It’s not a problem.

 

That's the first step...............looking how level the trailer rides.
After you know that ,the rest can be discussed.

 

What type of trailer? Unless it’s a tank of some sort or a livestock trailer I wouldn’t worry about it sitting perfectly level. On most trailers running taller tires than your truck won’t be a big deal at all. It will just bother your OCD if you’re like I am.

 

If it is a spread axle it might lead to the rear axle locking up more then the first axle when empty.

 

If you got good working brakes and parts. They won't lock up unless road is slick.

My current trailer would jack knife in the snow my first winter. New brakes and drums fixed that.