Re: Towing capacity - opinions needed
Are the vehicles equipped with the identical packages? The same brakes? Suspension? Once you exceed the suggested maximums then you take your chances.....what we are dealing with is more than just the ability to move the load back and forth down the street, you need to be able to stop and corner safely as well. GVW, towing capacities, tongue weights, and axle weights all come into play......and most people have no clue regarding any of them.
Finally we're getting to the things that actually limit towing ability.
Trailer tongue weight needs to be high enough to provide stability against sway. Most sources I've seen suggest a minimum of about 10% of the total trailer weight, while others suggest that boats can be stable with as little as 7%. You also need to make sure you don't overload the rear axle of the tow vehicle. The heavier the trailer and/or the lighter the tow vehicle, the closer these numbers are and the more attention to detail is required from the operator. Total cargo capacity should be listed on the door sticker - make sure the total weight of people and gear in the tow vehicle and trailer tongue weight is less than the maximum cargo capacity allowed. If the vehicle has a large rear overhang, one also needs to account for the fact that the load point is behind the rear axle, so hitching up the trailer will transfer some of the vehicle weight from the front axle to the rear axle. The residual cargo capacity may need to be cut even more in order to not exceed the rear GAWR. For vehicles with full frame construction, the weight transfer problem can be solved by using a weight distributing hitch.
You need to be able to stop quickly and in a straight line. Vehicle brakes are designed to stop the vehicle when it is loaded to it's GVWR. If the total weight of the combination exceeds that, braking performance may suffer unless the trailer has it's own brakes. Furthermore, pushing on a ball coupling is dynamically unstable - unless things are perfectly aligned so the trailer is pushing through the center of mass of the tow vehicle, there will be a sideways component to the applied force that will jackknife the combination if it can't be counteracted by the tow vehicle's tires. Properly functioning trailer brakes greatly reduce or eliminate the force and make the combination stable and stoppable. Trailer brakes are a good idea whenever the combination weight exceeds the GVWR and are required in many jurisdiction whenever the trailer exceeds half the curb weight of the tow vehicle.
It's also obvious that you need to be able to "move the load back and forth down the street" (and up the launch ramp). As you point out, this is usually not the limiting factor, although pulling a heavy load will put substantial stress on the engine and drivetrain. The key here is keeping things cool and lubricated. Big radiators and transmission coolers (for automatics) are common tow package parts, or they can be aftermarket additions. Full synthetic lubricants provide an additional margin of high temperature tolerance and are more resistant to breakdown under severe conditions. So long as cooling and lubrication do not fail, engines and transmissions can run for many hours at WOT without damage.
So let's apply this to the OP's question. Fully loaded, his boat will be in the 1500-1600 lb range and should have a tongue weight of about 160 lb. If it's too light or too heavy, he needs to move the axle to adjust it. The 2003 CRV has a maximum payload of 1060 lb. Lets take away 160 lb for fuel, fluids and unknown options, leaving 900 lb for other stuff. Accounting for weight transfer, the trailer might be putting 200 lb on the rear axle, leaving about 700 lb for people and gear. Maybe a bit tight, but workable unless he plans to have every seat occupied by someone over 200 lb. The combination will exceed the vehicle's GVWR, and the boat is very close to 1/2 of the CRV's 3250 lb curb weight, so although the combination would probably be borderline OK without them, I would add trailer brakes for anything more than a short, low speed trip to the boat launch. The manual transmission is a bit of a liability at the launch ramp, but it is an advantage everywhere else as it is immune to the heat issues that can kill automatics. For the engine, use high quality oil (preferably synthetic) and follow the "severe service" recommendations in the manual for oil changes and you can run it hard for a long time.
