It should do it as long as the engine is warm, the battery has sufficient charge, and you're not mashing too hard on the throttle. Been that way in every generation. It's one of the biggest factors in why the Prius gets better fuel economy in the city than on the highway.
ICE will tigger on hard acceleration from 0 mph, too. EV will operate up to 43 mph. Higher than that the ICE kicks in to keep MG rpm in survival range.
MY17 will definitely not go to 43mph. I don’t think it will make it to 20mph. And yes, hard acceleration will killing. iPhone ?
"if I am cruising at a steady speed" Yes, if you are not cruising, it will not be as frugal. It appears to me you are in the UK, perhaps Wales? I am in an extremely flat, warm part of the US. I can drive 156 miles and only gain 90 feet ( 250 km, 30 meters) It is easier to stay in EV operation if you never go uphill. At least some versions of the European v's got a smaller LiIon battery in the center console rather than the NiMH battery under the rear cargo area that we got in North America. In Japan "The Prius Alpha is available in a five-seat, two-row model and a seven-seat, three-row model, the latter’s third row enabled by a space-saving lithium-ion drive battery in the center console. The five-seat model uses a NiMH battery pack." It may be that you have a different battery than we are used to, as all North American v's are 5 seaters.
