I got my pack brake installed and have been running around town with it on. Does it effect MPG when using it ? The thing works great but I'm worried that I will loose MPG when just driving around town.

 

THE use of the brake, any exhaust brake doesn't bother your mileage unless you use it in place of "lifting" early and just coasting up to a stop sign or light. Think about it for a minute. You throttle up and hold it to get close to the stopping point and then lift and let the brake do the work of slowing down. The only thing you'll save is your brake pads from wearing... but if you lift early and just coast, then you save everything. I only use my exhaust brake on hills and when towing.