How to match a tow vehicle to a trailer

The Most important question to ask before buying an rv

Consider the following when matching a tow vehicle to a trailer:

(1) What is your vehicle’s tow rating? This is the first consideration you should use when matching a tow vehicle with a trailer.

(2) What is the trailer’s hitch weight, dry weight and gross vehicle weight? Hitch Weight or Tongue Weight is the amount of weight sitting on the ball of the hitch or in the back of the truck. For a trailer this can be minimized with a weight-distribution hitch.

Gross Dry Weight or Unloaded Vehicle Weight (UVW) is based on the standard model features. It is the weight of the actual unloaded vehicle without cargo, fresh water, LP gas, optional equipment, or accessories. You need to add the weight of optional equipment to get the actual weight of the trailer.

Gross Vehicle Weight Rating (GVWR) is not the weight of the trailer. GVWR is the maximum amount the vehicle is rated to carry. Everything that contributes to the weight of the tow vehicle features in this rating including the base unit dry weight (UVW), all fluids, cargo, optional equipment, and accessories.

Axle Weight is the proportion of the UVW that is supported by the axles, tires, and wheels. Gross Axle Weight Rating (GAWR) is the maximum load weight, in pounds, that can be placed on the axle.

You can learn more about trailer weights here.

(3) In addition to the trailer, how much weight will you load in the trailer and vehicle? Consider if you’ll be hauling a dirt bike or motorcycle in a toy hauler, your mountain bikes, other toys, people, dogs, etc.

(4) What type of conditions will you frequently encounter? steep grades, high altitude, extreme temperatures, wind? All of these can affect the type of vehicle you use and the way your trailer tows.  Wind can cause sway and, if it’s a headwind, wind resistance can be an issue with particularly wide or tall trailers.   

(6) What special conditions requiring added traction are you likely to encounter? off-roads, snowy roads, unfinished roads?

(7) Is the trailer equipped with trailer brakes? Does the truck need or have a brake control? 

Surge brakes are independent hydraulic brakes activated by a master cylinder on the trailer tongue. The tow vehicle’s hydraulic brake system should never be connected directly to the trailer’s hydraulic system. Since there is not any electricity to the trailer, surge brakes are commonly used for boat trailers and small trailers that may need brakes.

Matching a tow vehicle to a trailer
Sample Trailer Brake Control Image

Electric brakes usually provide automatic and manual control of the trailer brakes. The tow vehicle must be equipped with a brake control and additional wiring. The brake control is installed within reach of the driver and can be applied manually or automatically when the brake pedal is applied.  This type of brake control installation can usually be done at your RV dealer’s service department.

(8) What type of electrical connection does the trailer require? 4-wire, 6-wire, 7-wire, other? 

Sample 7-way plug

Wiring your tow vehicle or trailer should only be done by someone with electrical experience. Wiring the plug incorrectly can damage the tow vehicle or trailer. Most trailers without brakes use a 4-wire plug. Trailers with brakes but no separate battery usually have a 6-wire plug. Most newer RV’s have a 7-wire plug to charge the battery when you are traveling. There are other plug configurations that are not as common for general usage.

Hitches for matching a tow vehicle to a trailer

(9) What type of hitch does the truck and trailer require? receiver hitch, weight-distribution, fifth-wheel, or gooseneck

Receiver hitches range from Class I to V with townig capacities ranging from 1,000 pounds to 17,000 pounds and square receiver opening of 1.25 inches, 2 inches, and some 2.5 inches. Class II and IV receiver hitches can be used with weight carrying hitch or weigth distributig hitch. The receiver hitch typically bolts to the vehicle frame and is designed for use with a removable ball mount.

Weight Distribution Hitch

 

Weight Distributing hitches are used when towing heavy or long trailers. There are bolt on styles or weld on styles. A weight-distributing hitch setup is mounted on the tow vehicle that uses spring bars under tension to distribute part of the trailer’s hitch weight from the towing vehicle’s rear axle to the towing vehicle’s front axle and to the trailer’s axle(s). It can help reduce trailer sway and hop.

Fifth Flex Hitch

 

Fifth Wheel hitches are designed to be installed inside the bed of the truck and must remain in front of the rear axle. Hitches are rated from 15,000 pounds to 30,000 pounds, you want to try to match your towed vehicle to the hitch rating. There are fixed hitches for long box trucks and slider hitches for short bed trucks. Slider hitches come in manual style that you adjust for tight corners and automatic style that self adjust as you turn the truck. It is recommended that you have an extended pin box for short bed trucks. Fifth wheel hitches can be removed, but are heavy and usually the rails are left in the truck bed.

 

Have more questions about matching a tow vehicle to a trailer? Come see us at 2122 Hwy 6 in Grand Junction, Colorado!