Stationary bike, vigorous effort (Search Cardio)

Hi I just started here, and was wondering about the exercise database. I'm doing a few exercises and tracking them using the suggested calories that come from the exercise database.

I have a nordictrack recumbent bike and use it on the "Endurance 4". The levels within the exercise go from 6 to 20 as your peddling (2 is the lowest and 20 is the bikes max). The exercise goes up and down hills for 45 minutes. almost always your above 12 and on the hill tops you spend 2 minutes at 16, 18, 20, and 16 again- then a cool down. I think 28 minutes are above 14. I,m doing just over 9 miles or 12 mph.

This is a really hard exercise for me (I'm 232lbs), I drink about a quart of water, my heart rate is up almost the whole 45 minutes, I'm sweating. I get off the bike and my legs are a little wobbly. I mean its really hard.

I'm using "Stationary bike, vigorous effort (bicycling, cycling, biking)" and for this exercise I get 1154 calories. That seems a little high to me.

So how accurate are the calories in Search Cardio Exercise?