That the upcoming hybrid electric-turbine Ariel ‘P40’ supercar will ‘only’ run flat-out for 15-20 minutes or so is no accident.
After that, its batteries will be sufficiently depleted that it operates in a ‘fast road’ kind of mode, mooching around on power supplied by its little 47bhp turbine engine only, until the batteries are replenished.
Ariel has investigated the kinds of use that sports cars get, see: fast road stuff and track days. It has calculated that you’ll be unlikely to ever exhaust its performance capability on the road – heck, it’s unlikely you’ll even use it all on the road. Fallback power of a 47bhp turbine might not sound much but, when given that running at a steady 70mph probably only uses 20-something of those horses, you get a lot in reserve most of the time.
And while you will exhaust the P40’s capability on a circuit, the chances are you’ll have exhausted yourself first: a sweaty track session, or a couple of laps of the Nürburgring, tend to be plenty in one dose. Strikes me that it’s an intelligent and bold move, and one really that only a company like Ariel can make, to admit that: sure, at some point, this car will lose its performance capability until you take a breather.
Hybrid hypercars have, so far, tried to emit a less compromised vibe. The LaFerrari, McLaren P1 and Porsche 918 Spyder have incorporated hybrid technology to boost acceleration and have a top speed you’ll never be able to reach on a race circuit, while trying to ensure that the engine is sufficient to keep the battery-assisted oomph available every time you ask for it. See also: the Honda NSX. That means these cars carry massively powerful petrol engines.
Even then I’m not sure they get away with it. McLaren’s engineers were curiously underwhelmed with some of the high-speed acceleration figures we returned on the P1. My suspicion was, is, that they came during a heavy acceleration session on Mira’s horizontal straights, and that this repeated flat-out max-power acceleration tired it. That’s not something you’d experience in a P1 anywhere else, because no race track has a straight long enough.