I don't think it uses the base maps at all in the calorie calculation, I think it just looks at the GPS triangulation, which is wildly inaccurate. I'll come back from my usual 37-miler in Florida and it'll say I've climbed 900 feet . No, it isn't dead flat, but there sure isn't 900 feet of climbing - 60 feet or so over the bridge each way and four or five 10 foot humps.

When I recalculate the calories in SportTracks, that usually takes it down by about 25%. But it still apparently doesn't consider the HR. So I get basically the same values if I'm doing the ride in a paceline, solo in still weather, or in a 25 mph wind. So I guess I've answered my own question