An algorithm residing in, for example the ECM of a motor vehicle, which predicts brake booster vacuum for vehicles using vacuum for brake pedal assist. The predicted brake booster vacuum is compared to a calibrated brake booster vacuum threshold to determine if adequate brake booster vacuum is available to meet vehicle braking requirements, whereupon engine operation can be modified, as necessary, to improve intake manifold vacuum such that brake booster vacuum requirements for vehicle braking are better satisfied.