Just a few ginger miles into our trip, consumption halves to 1.2kg/km. But to have a chance of eking out our hydrogen reserves to 230 miles, I’ll have to score a running average of 0.9kg or less, warns Hunt. So we’ll be holding up traffic shortly.
There’s little of it about at first, though. We amble along at 50mph or so, enjoying the Mirai’s boldly individual dashboard. There’s much staring at the consumption read-out, of course, but also the swooping edges and hard corners of the infotainment display and the centre console. It’s not an especially beautiful piece of sculpture, this dashboard, but it’s interestingly busy, rather like the Mirai’s oxygen-gulping, air-cleaving body, which is now occasionally being impeded by traffic. More often, though, it’s the other way around: the desire to go slowly and conserve our hydrogen supplies (now that sounds like a phrase of the future) is still strong despite a consumption rate that has fallen to the desired 0.9kg per 100km.
Soon will come hills, however, in the undulating and picturesque form of the Cairngorms. Why climb when we could travel more flatly closer to the coast? Because it should be quieter, and because theM1, when it comes, will be a long and dull contrast. To improve our economising, snapper Luc Lacey joins the back-up Land Cruiser with all his kit to reduce the Mirai’s load, and I run with the air conditioner off, which is more of a sacrifice than it might sound on this sunny day in spring-like Scotland. The Cairngorms promise an entertaining challenge – the aim being to avoid heightening the Mirai’s hydrogen appetite despite an assortment of ascents.
With ascents come descents, of course, offering the chance for some fuel saving, and potentially of the exciting kind. Exciting economising? Absolutely, because the aim is to gain as much downhill momentum as you dare and conserve it, ideally with the minimum of braking. Given that there’s an on-board, fuel cell-supplementing, nickel- metal hydride battery pack in regular need of a charge, avoiding the brakes mightseem a surprise because you’d expect to use them to provide regeneration opportunities. However, there’s no scope for regeneration with the Mirai, explains Hunt, because there’s only one motor, andit therefore can’t double as a generator. The brakes are to be avoided, then, within safe reason. Still, when you’re gaining speed down a Cairngorm and trying not to lose it, that can get quite thrilling.
The roads are empty enough to uncover a slightly unexpected and deeply pleasing quality of the Mirai, which is that it will comfortably navigate corners at quite a pace and minimal drama, despite its relatively simple MacPherson strut, torsion beam axle suspension, and a fair bit of heft. One major reason is that it is low-lying heft – its fuel cell, battery and motor packaging providing a low centre of gravity. Another is decent chassis balance. This is no sports saloon, but the Mirai is certainly fleet of low-rolling-resistance foot, besides providing encouragingly precise steering.