Rather than post how I set mine up (different vehicle), I e-mailed Roadmaster.
Here is the reply:
The short answer is that we recommend 65 lbs. for the 2005 Honda CRV. Also, we have a reference chart that states the recommended pressure for many popular towed vehicles:
http://roadmasterinc.com/pdf/inv_resource_guide.pdfThe long answer is that the pressure we recommend assumes the cable has been attached to the brake pedal arm as low as it can be mounted so that it is just above the brake pad you step on. Some installers mount the cable higher on the brake arm which reduces leverage. In these cases a higher air pressure is required to achieve the same braking performance.