MSP,
Don't forget to add *your* body weight to the data entered. Determine the stock weight of your car/model, add maybe 50-100 lbs for extra options (airbags/TC-ABS/AAT/etc), then maybe another 100 (?) lbs for the dual exhaust, plus your new wheels, etc. Then, add your body weight.
Thus, for a V6 premium (3371 lbs), plus some extras (50 lbs) plus your exhaust/wheels/tires (100 lbs), plus body weight (160 lbs) – I’m being VERY conservative and thoughtful with these numbers – we arrive at 3681 lbs. The actual weight w/ driver is probably more like 3750 lbs depending on your options.
Try entering 3750 for the weight and see what you get. The number should be around 206.5 HP since 3750 is about 9% more than 3450. 206.5 rwhp is around 243 HP at the crank for a manual transmission (15% loss). 243 sounds more like it, not bad for not even having the proper tune.
The difference in weight between the Deluxe and Premium versions is 148 lbs, so just the Shaker 500 and power seats add some significant weight. Also, I don't know if the car weights indicated by Ford are the dry or wet (with oil, coolant, gas, etc) weights. The wet weight may be greater than 3371 for the premium. Assuming you weigh at least 160 lbs, you should definitely use 3750 for the "test" weight.