Trailer TypesTrailers, like automobiles, are manufactured for thousands of applications and come in all shapes, sizes and configurations. As with cars, these differences in individual trailer specifications can mean the difference between a trailer that pulls cleanly and smoothly behind your rig, and one that bucks and sways like a wild mare at a Sunday rodeo.

OpenAn open trailer is one that exposes the trailer load to the outside environment. This design features a flat, usually metal or wood surface that's opened in the center. Utility trailers have low side rails on three sides; racing trailers do not. These trailers don't provide any protection for their contents, but tend to be lighter and provide less aerodynamic drag than enclosed trailers. Open trailers also offer the advantage of being relatively inexpensive, costing about $1,400 to $2,500 new.

EnclosedAn enclosed trailer provides protection from the outside environment and provides an added measure of security because the trailer functions as a portable, lockable garage. These trailers tend to be heavier and less aerodynamic than open trailers; they're also more expensive. Enclosed trailers usually cost in the $4,000 to $6,000 range (new), but can go much higher.

Single AxleA single-axle trailer has just that: a single, load-bearing axle. These trailers can be found with or without brakes, either enclosed or open. Single-axle open trailers are rare, usually reserved for small cars (few will hold anything longer than 14 feet). Suspension is usually of the leaf spring variety. This type of trailer is ideal if the combined weight of the trailer and contents is under 3,000 pounds; trailer brakes are then optional. Anything heavier than that requires the use of brakes (in most states a legal requirement, common sense everywhere else). Single-axle trailers tend to be unstable on the road and don't track as well as dual-axle units. However, according to a spokesperson at TrailersForLess (in Fayetteville, Georgia) the world's largest online trailer store, the difference is slight and shouldn't scare you away from a well-built single-axle trailer if you have a small lowrider (under 2,000 pounds).

Dual AxleA dual-axle trailer uses two load-bearing axles, and can be either open or enclosed. These units usually feature either leaf springs or independent torsion bar suspensions. Brakes are recommended, if not required. A dual-axle trailer tracks more accurately over varying road surfaces. In addition, if there are brakes on both axles (which is not usually the case) braking capacity is double that of a single-axle design.