Tires - going larger - how big?Even the largest of these mini-trailer factory tire options aren't that big. The 4.80x12" tires on a 12" x 4" wide rim are only 20" tall. This makes the clearance under the trailer axle of 9". Using my TJ as a reference with an RE 3.5" lift and 285/75/16" (33") tires, the clearance under my Dana 44's pumpkin is 9.5". And these trailers come with a 4-on-4" bolt pattern on their axle.With these 4.80x12" tires (and I would expect the same with the 4.80x8" tire) and the factory width axle, it leaves about 1" of clearance between the side of the tire and the side (frame) of the trailer. Not a lot of room for a wider tire and rim.The largest wheel you can get with a 4-on-4" bolt pattern is a 13" rim (and it's about 4.5" wide). A common trailer tire size is a 175/80/13" tire (around 24" tall). Would that fit on a factory axle? Maybe, but the tire would be awfully close to the trailer frame; too close for my taste; but tow your trailer to Walmart and see if they'll let you do a test-fit in the parking lot. It would raise the trailer up 2", and increase your trailer axle clearance 2" (now up to 11"). I'm just mentioning this in case someone was thinking about this as an option. If a trailer place would let you try mounting a four-hole 13" rim and tire on your trailer as a test-fit give it a shot. I wouldn't go spending the money for the wheels and tires to find out later they don't fit.Any larger size wheels need a 5 on 4.5" bolt pattern, and I'm not even going to talk about 14" wheels; I'm going to go straight to 15" tires and rims. And you'll be needing a wider axle from here-on-out (we'll talk more about this later).The next larger size tire is a 205/75/15" tire, and I'll only be talking about trailer tires - not passenger car tires. A 205 tire is about 27.4" tall and about 7.7" wide. These are usually put on a 15x5" rim. The tires I purchased are Loadstar Bias Ply ST205/75/D15 load range C from http://www.etrailer.com/Tires-and-Wheels/Kenda/AM1ST92.html mounted on a set of Dexstar 15x5" rims http://www.dexstarwheel.com/products.html#changer . The tires were about $75.00 each, and the wheels were about $40.00 each. I wanted black spoke rims to match my Jeep's rims. I ordered three wheels and tires from etrailer.com for about $347.00 (free shipping for orders over $150). I still had to get them mounted and balanced, so that cost a few cents under $40. Unfortunately etrailer.com accidently sent me silver rims instead of black, so we made a price adjustment, and I'll be running silver rims instead of black; they were very pleasant about the whole thing. If you're not as picky about your rims as I am, you can maybe get them cheaper (and already mounted) from places such as http://recstuff.com/ST205/75D-15TrailerTireLoadRangeCon5BoltSilverSpokeTrailerWh ee.aspx or your local trailer place. This size rim and tire are very common. This size tire will increase your clearance under your trailer's axle to just over 13" (remember, the lowest point on my Jeep's Dana 44 with 33" tires is about 9.5").The next larger size trailer tire is a 225/75/15" tire, and it measures at about 28.1" tall and about 8.4" wide. These are usually put on a 15x6" rim. I didn't think the added cost per tire (compared to the 205/75/15" tire) was worth the small amount of increase in height. And I think anything a lot larger than this your trailer is going to start looking like it's on steroids - dare I say look like a freak? And we haven't even addressed the wider axle and fender issues yet. A 235/75/15" tire on a 6 or 7" rim would look nice and large on a little 4' trailer without being oversized (or overly stressing the spring mounts).Someone may ask "but why don't you make it so you CAN use your Jeep's tires on the trailer; that way you only have to carry one spare? Besides the "steroids" thing, that's a lot more trailer weight for your Jeep to be pulling (I at least am trying to keep my trailer's weight and cost down while lifting it), if I'm out in the boonies I want a little bit of redundancy built into my equipment I'll take a spare for the Jeep and one for the trailer thank-you. You'd also need a more HD axle like in the 3500 lb range (more money), plus it might just overtax the lighter-weight metal used in these mini-trailers. I guess you can do whatever you want, but in the interest of keeping the trailer cost and weight down, I'd skip the super large tires on a little trailer such as this - you're still going to have more clearance under the trailer axle with a 205 tire (just under 13") than you would on your Jeep with even a 35" tire (figure about 10.5" - 11" with a Dana 44). Also go too large a trailer tire and you'll be hitting the tail light assemblies.Today I also ordered three black chrome center caps for the wheels from http://recstuff.com/319-Chrome-Center-Cap-Black.aspx (including shipping $24.00). I still need to find some black lug nuts to match, so add the cost of center caps and lug nuts to your trailer's cost if you want them on your trailer. You don't have to run with a center cap, and chrome lug nuts are cheap.Here is a picture of a 175/80/13" tire beside a 4.80x12" tire (taken at Walmart while they were mounting and balancing my 205/75/15" tires), and a few shots of my new 205/75/15" tires beside my trailer's 4.8x12" tires. And you'll be able to see how my trailer becomes the "box storage unit" when parked in the garage. And you can also tell how the new tires look a LOT larger than the factory 12" tires & rims.