Tuesday

No range anxiety. For all the technology on board, that’s the detail which should grab businesses’ interest. There’s a large 85kWh battery pack sandwiched into the car’s floorpan, offering a range of over 500km on the NEDC test, or 400-410km according to an average over the previous fortnight. That’s good going for a press car.

The acid test, though, is whether it comes anywhere near. Long range will make this attractive as a long distance car, but high speed driving tends to blunt range in EVs because there’s no opportunity to lift off the throttle and regenerate. As a luxury car, it’s important that this isn’t true of the Model S. Looping from the dealership in London to the IFW office, then back to Cardiff in the space of one afternoon, would mean throwing this in at the deep end.

But there’s no adjustment in driving style here, as there often is with electric cars. It’s possible to track your last 50km of driving and get a predicted range via the dashboard display, and air conditioning and the novelty of the way this car accelerates don’t seem to punch a hole in its range. Press the brake pedal to start the drivetrain, slot it into drive, and use it normally.

This is important. Tesla is installing its own charging network, called Superchargers, across Europe and will offer free top-ups for the lifetime of the vehicle. Spanning from the Arctic Circle to the French Riviera, this will make long-distance travel easy for Model S customers, requiring a half-hour stop to regain 80% of the range. While this network grows, the ability to easily cover the distance between them is really important.

In the UK, there are only a handful of Superchargers, but the Model S uses the same Type 2 connection as most European EVs and can take a relatively fast 22kW charge at many service stations across the region. Thankfully, most also have free WiFi.

Wednesday

Rolling the garage door open to see the dew-covered Model S still charging on the drive, it’s not difficult to see why this has generated so much hype. Looking like a stretched coupe on its optional 21-inch wheels, the digital dashboard and that explosive power delivery mean first impressions are its forte.

But that doesn’t always translate into long-term satisfaction. Complicated infotainment systems, nascent charging infrastructure and overall functionality can fall short on plug-in cars. This is up against stiff competition as a performance saloon as well as a luxury car, and the nagging feeling is that the novelty could wear off when it’s tasked with replacing established rivals.

After a brief top-up on the way home, I’d arrived in Cardiff with almost a third of the range left. But, after almost 14 hours connected to my home wallbox, the Model S was still taking energy on board when I pulled the plug to run some local errands on my lunch break. That enormous range comes from a battery with almost four times the capacity of most EVs, but this also means it will take almost four times as long to ‘brim’ it using a home wallbox.

With a full charge taking 30 hours on a plug socket or basic 3.6kW/16 amp home charging point, upgrading to at least a 7.2kW/32 amp unit or Tesla's own wallbox is a no-brainer for regular long-distance drivers. But, unlike most electric cars, there's enough range to do shorter commutes with a part-charged battery.

Thursday

Though the Model S arguably has a broader appeal than most electric vehicles, early adopters are likely to be weighted towards businesses with sustainability at the core of their mindset, as well as an eye for technology.

Treglown Court, the purpose-built home for the Cardiff, Wales practice of Stride Treglown architects, has a lot of parallels with the Model S. Both are designed from the same blank-page ethos with energy efficiency at their core. In the building’s case, this includes movement-activated low energy lighting, efficient boilers, recycled rainwater and using the natural movement of warm air currents through the building instead of air conditioning.

With a 106m2 photovoltaic array on the roof and south facade, Treglown Court produces more energy than it takes from the grid, achieving Carbon Zero status and an A+ Energy Performance Certificate. Like the Tesla, it’s a billboard for a company wanting to demonstrate environmental credentials without sacrificing functionality. It’s forward-thinking.

The rich pearlescent red paintwork didn’t take long to draw a crowd from the glass-fronted office. Simplicity of form came highly praised inside and, in an environment where Tesla’s key rivals have a foothold in the car park and design counts as heavily as clever engineering, the Model S stood up to close scrutiny. If Treglown Court offers a glimpse of the ESOS-era business of tomorrow, then the Model S is a hint of what might be parked outside.

Friday

'Isn’t this a massive distraction?' a friend asked from the passenger seat, playing with the Tesla’s 17-inch display screen. Almost all functions are controlled via this tablet-like display, which means new features can be added with software updates – a little like a smartphone – as the car gets older.

I’d stopped noticing it. Despite the technology-rich dashboard, it’s so logically laid out that it is an asset rather than a challenge. Tesla includes a three-year data package, to power the internet radio, offer remote access via the smartphone app and the Google Maps navigation. It’s so responsive to use and beautifully designed, that it makes you wonder why all manufacturers don’t do infotainment systems this well.

But it is really a reminder that Tesla has come from a technology, not an automotive background, engineering the Model S from a blank sheet rather than a legacy of building cars. So it switches itself off and locks the doors as you walk away, the air suspension remembers where it needed more ground clearance, and the navigation automatically scans your commute for traffic before you set off. Next year the Model S will get sensors that will eventually allow semi-autonomous driving. Data isn’t an add-on, it’s what makes this car tick.

Saturday

As a new Dad, I’ve recently become very aware of flexible in-car storage. Supposedly it’s a detail that’s not too difficult to get right, but memories of struggling to fit baby paraphernalia into other cars has proved that it frequently isn’t.

Considering its coupe-like silhouette, the Model S couldn’t be much more practical. There are two ISOFIX points on the folding rear bench and boot capacity, at 744 litres, is 50% bigger than most estates, accessed via a large motorised hatch rather than a pokey saloon bootlid. This also drops into a large additional compartment ideal for storing charging cables, so there’s plenty of space for a buggy.

With the motor and transmission between the rear wheels, the added string to the Tesla’s bow is there’s another large boot up front. So the back end of the car can swallow heavy or dirty items like buggies, golf trolleys and so on, while overnight bags, laptops and food can go in the front, in a useful mud-free compartment where there’s nothing to tear the bags open. It’s brilliant.

There are some frustrations for long-distance drivers though. Tesla has made a feature of the car’s flat floor by fitting a large storage bin under the touchscreen. There are no door pockets, no grab handles, only two cupholders and the bin isn’t textured to stop phones, coins and charging point cards sliding around. On an otherwise well thought-out car, these are surprising omissions.

Sunday

The P85+, which until recently was the most powerful version, produces a supercar-worrying 420hp. It’s fun in short bursts, but what’s different here is that the range is long enough to actually go for a drive. You can get a long way from the city in the Model S, and the potential to get from Cardiff to the Brecon Beacons and back (160km) on one charge is an entirely new experience.

There are few places less electric vehicle friendly. The National Park’s topography may be gorgeous to look at but steep hills have the potential to suck energy out of the battery at an alarming rate, and the most dramatic scenery strays far from the nearest slow charging points, let alone the M4’s rapid chargers. Run out of range in Brecon, and it’ll take at least three hours to get enough charge to crawl to the nearest Electric Highway point.

Out in the countryside and with the large panoramic roof reclined, there’s only the faint whoosh of under-load electric motor to disturb the near silence. Each steep climb put a spike on the main display’s energy graph, in turn reducing the available range, but never enough to worry about getting home again.

This left me free to enjoy the drive. The sportier front seats are a must-have but, for a large and heavy car, it’s neither unwieldy nor unnerving on winding Welsh roads, and most of the weight is in the battery, which is the lowest part of the body. This is a similar size to a 6 Series Gran Coupe and, though it’s definitely more of a 650i than an M6, the Model S is an addictive way to cover ground and enjoyable without the nagging worry of a flat battery. 

Monday

Bristol, England, and another meeting, beckoned. It’s an easy 150km round trip over the Severn Bridge, which meant there would be no need to seek a charging point en route, and I could treat the Model S like a normal diesel-burning motorway car, just as a business user might.

It’s a great tool for the job. Undoubtedly the air suspension on the P85+ (usually a €2,200 option) helps with ride quality, but it takes rough surfaces better than many cars with wheels far smaller than the 21-inches under each corner of the test car. The flip side, with no engine noise, is it’s harder to ignore the roar of low profile rubber on tarmac at motorway speeds.

After six days, it’s starting to dawn on me just how significant this car is as a moment in motoring history. This is the point at which electric vehicles become genuinely usable long-distance travellers, not through a reliance on a conventional engine as a backup, but through a structured approach to building a car and the infrastructure to go with it. The Model S doesn’t work because it’s a halfway house, it works because it’s a brilliant electric vehicle.

And that’s not a given, even at this price point. A top-spec Model S is competing head to head with plug-in hybrid versions of the Mercedes-Benz S-Class, Porsche Panamera and BMW’s ultra-futuristic i8 supercar. None of those can offer the same interior flexibility or charging options. Tesla may be a newcomer, but with a compact executive EV on the way and a blank sheet approach to building cars, it’s setting some high standards for the rest of the market which last long beyond first impressions.