900lbs less weight than what the V8? the V6? When comparing to the previous generation Colorado (the V8 weighted around 3900lbs), the new Silverado weights an average of 5000lbs, so I don't see mass weight savings? It may be longer and have more room, but it's not lighter?
The 3.6L in the Chevrolet Traverse that weights 4800lbs, is adequate, so it should be good in the 4000lbs Colorado. Hopefully the transmission gearing is better in the Colorado, than in the Traverse, which makes it feel slow because of early upshifts.