Based on the press launch test route a manufacturer chooses for its particular model, you have some idea of its confidence in a car's abilities.
Smooth, unchallenging motorway routes point to a model aimed at refinement, rather than driving enjoyment, while more twisty routes suggest a focus on handling.
So Vauxhall's choice of a 300-mile test route for the new Astra, ranging from city driving, to motorways and some of the most challenging, twisting roads in the Lake District, suggests it believes it is on to a winning all-rounder.
Not that it has ever been anything less than successful, despite the flaws of the outgoing model.
It may have played second fiddle to the Ford Focus for the past few years, but since 1980, about two million Astras have rolled on to Britain's roads, with 102,000 being sold in 2002 alone.
So considering that it hasn't been at the forefront of ride, handling and quality compared to some key rivals, you can sense Vauxhall's confidence that the fifth generation Astra will be a success is well founded.
The UK will be one of the biggest markets for the new car, where about 48,000 units should hit the road by the end of this year.
Yet despite its almost guaranteed success on the forecourts, the new model, on sale from Saturday, is a world away from the current Astra, hence the varied and challenging route from Newcastle to Lake Windermere.
Vauxhall will be offering the five-door hatchback at launch, followed by an estate with extended wheelbase in the autumn and the three-door hatchback will arrive next spring.
The new design does away with the dull but worthy appearance of the current model, instead favouring sharp lines, bold headlamps and a high-quality interior.
New Astra also offers 350 litres of boot space with all the seats in place, rising to 1,270 litres with the seat backs folded flat. After years of living in the shadow of the Ford Focus, Vauxhall has devoted much attention to suspension, ride and handling.
Extensive work has been carried out to tune suspension for specific models and engine types in the range. There will be four petrol engines available at launch, starting with a 1.4-litre 90bhp, with a 1.6-litre offering 105bhp and a 125bhp 1.8-litre.
There is also a turbocharged 170bhp 2.0-litre, while sources suggest there will be high power variants in future with 200bhp and even more from the same engine.
The two diesels on offer at launch are 1.7-litre common rail units, one with 80bhp and the other with 100bhp.
Later in the year, a 150bhp 1.9-litre diesel offering a 130mph top speed and 0-60 time of 8.6 seconds will be added to the range.
All units meet Euro IV emission standards. Power is mated to a five-speed manual gearbox in most models, with the 1.8 getting a four-speed auto as an option while the 1.6 has the clutchless manual Easytronic transmission on offer.
The 2.0-litre turbo and 1.9 diesel come with a six-speed gearbox. With the Astra joining an increasingly tough battle for market share, Vauxhall has put some of its greatest investment into interior equipment.
Standard equipment is good for even base models, with 'Expression/Life' specification getting driver and passenger front and side airbags, ABS, power steering, rake and reach adjustable steering, remote control central locking, electric front windows, CD player and in addition, 'Life' gets air conditioning.
'Club' gets 15-inch alloy wheels, full-size curtain airbags, steering wheel mounted audio controls, electric mirrors, and body colour mouldings.
'Design' adds 16-inch alloys, sports front seats, leather covered steering wheel, a radio with MP3 compatible CD player, electric rear windows and rain sensitive windscreen wipers.
'Elite' adds climate control, cruise control, leather trim, the 40/20/40 split rear seat and a centre rear head restraint.
SXi and SRi get better wheels, lowered suspension, new instruments, front fog lights and the SRi gets ESP plus to aid handling.
From the autumn, Astras can be specified with keyless entry. Service intervals vary between 20,000 miles and two years for the petrol to two years and 30,000 miles for the diesel.
Prices start at £10,995 for the 1.4-litre Expression, with £1,000 added for Life, another £1,000 for Club and a further £500 for SXi.
For the 1.6, prices start at £12,495 and rise to £13,995 for the SXi, while 1.8 models cost about £500 extra. The 1.7 diesel range starts at £13,545 for the 80bhp version, with an extra £1,300 buying the base 100bhp model.
Behind the wheel
A SERIES of demanding and occasionally unforgiving roads on the moors above the Lake District tested the new Astra to its limits – and mine.
Admittedly, all models were provided with sporty 205-width tyres, rather than the standard rubber that fleet drivers will have, but despite this I could still tell what an accomplished car the new Astra is compared to the current model.
Stepping into the car for the first time, the driving position felt as though I was perched too high up, but after a few miles, I soon settled in.
The switchgear is well placed and the steering wheel (admittedly the leather-bound option) is nice and chunky, with a weighty feel to it.
The low-placed gearlever for the five-speed 'box I tested fell immediately to hand and I felt it switched between cogs more smoothly and cleanly than other Vauxhall manuals, including the Vectra, although some testers on the launch disagreed.
In the centre of the dashboard, there is an information screen which differs according to the specification you choose. They range from garish orange to full colour that does everything but make the tea.
The entry-level 1.4-litre engine, while offering just 90bhp, is potentially the pick of the bunch, offering smooth, if sedate acceleration. It happily keeps up with motorway traffic, although it does fall behind on more challenging roads and hills, despite frantic gear changing.
The same is true of the sweet-revving and quiet 1.6-litre, which offers better straight-line acceleration, but still suffers on hills, requiring a change down from fifth on motorway inclines at 70mph.
The 1.8-litre was rather more raucous, but climbed to its rev-limiter on steeper roads with ease.
However, when it comes to sheer point and squirt acceleration, the 1.7-litre diesel (tested in 100bhp form) wins hands down. It still suffers from noticeable diesel clatter, but this soon settles down at speed.
So long as the revs are kept above 2,000rpm, there is plenty of low-down grunt, with the variable suspension set-up keeping the nose in line on tight corners, despite the heavier engine.
On the tight twists of the circuit, the Astra proved a strong performer and the suspension set-up never felt too hard, while the strong brakes remained fade-free, even under the most severe pressure.
But the suspension's ability to transmit the nuances of the road surface wasn't matched by the steering, which had little feel, but responded to inputs well.
The controversial indicator stalk, which doesn't click but stays on for three ticks or permanently depending on how hard you nudge it, remains but some subtle design and software changes mean it now feels more like a 'normal' indicator and is less confusing when trying to cancel a signal.
Although engine noise was subdued in all models, wind and road noise at speed could be quite intrusive. However, it was still possible to speak to a back seat passenger without needing to raise my voice.
The current Astra is already a fleet favourite and it is almost guaranteed the new model will be a sales success too. But buyers investing in the new Astra will be rewarded with a much better looking car that is not only up with the best for ride and handling but also offers great levels of equipment.