We're not talking here about an economy run, either. This was a family trip to the Drakensberg mountains, with lots of fast running on the highway, much enjoyment of the twists and turns once we hit the tight rural sections, plus, of course, a fair amount of dawdling along looking at the scenery when we went sightseeing.
The Renault Laguna 1.9dCi is powered by the F9Q direct injection diesel engine, which delivers maximum power of 88 kW at 4 000 r/min, with torque 270 Nm at a lowly 2 000 r/min.
This latter figure endows the car with effortless overtaking and hillclimbing ability, particularly at altitude. The torque curve is in fact a flat plateau, which means there's oodles of pulling power available right across the rev range, and virtually from walking pace.
Interestingly Renault claims a combined urban/extra urban cycle figure of just 5.5 litres/100 km - which compares well with our 5.6 litres/100 km. The town and country figures are 7.2 and 4.6 litres/100 km respectively. And this from a car that can dispatch the 0-100 km/h sprint in 10.7 seconds, and reach a top speed of 200 km/h.
The feature list in this car is the same as that found in the Renault Laguna II 2.0 Expression.
One of the most interesting features - still - is the Renault Card keyless entry system that also unlocks the hatch and fuel flap. The Laguna doesn't have a normal ignition/door locking key, but instead has a flat "credit card" key that incorporates remote opening and closing.
"Keyless" entry means there is nothing for thieves to attack to get into the car. The car can only be opened via the electronic beam, and this is transmitted via a "rolling" code that thieves won't be able to intercept.
There are no locks to "pick" or otherwise savage, and the electronics make it impossible to start the car or turn the steering unless the card is inserted into its slot to the left of the steering column.
Only then can the "Start" button be pressed and the car driven.
Features are extensive, too. Owners benefit from electric windows front and rear, radio/front loader CD with satellite controls, electrically-operated exterior mirrors, heat reflective windscreen, trip computer, height adjustable driver's and passenger's seats - the former with lumbar support - climate control air conditioning, tyre pressure monitor, pollen filter, and a steering column adjustable for rake and reach.
There are additional 12V power points - inside the centre console box, where it can be used for charging your cell phone - and inside the load area, ideal for a cool box.
There are semi-leather seats, and a number of additional oddment storage areas.
From the outside, this higher-specced version is distinguished by its colour-coded door and hatch releases, and front fog lights.
With its hatchback design, the Laguna boasts exceptional versatility, and like other Lagunas, the diesel version has maximum luggage volume is 1 330 litres, with 430 of that available even with five adults aboard.
Talking of which, we DID carry the full complement of passengers at various stages, and all commented on the legroom and the comfort of the rear seta.
All Lagunas come with six airbags, dual seatbelt pretensioners for the driver, anti-lock brakes with emergency braking assistance, and a tyre pressure monitoring system. In addition, Laguna is fitted with ESP and traction control.
This makes the Laguna one of the safest cars in its class - THE safest if you relate back to the fact that the Laguna was the first family car to get five stars in the tough European NCAP crash test.
Styling is a big strongpoint the Laguna, the five-door layout allowing for a fastback rear while still giving plenty of headroom in the back seats.
The front is flat and wide, with a "smiley" grille flanked by flattish twin optic headlamps, the "smile" emphasised by metallic-look relief trim that almost adds a handlebar moustache!
The windscreen is steeply sloping to maximise aerodynamics, and the tail has a "two step" appearance that's very reminiscent of the new BMW 7 Series - although the Renault came first.
The look is completed by a built-in tail spoiler and a hatch back that dives deep into the bumper to allow maximum access, while rubber inserts give protection to the colour-coded bumpers and the car's flanks.
On the road the Laguna Diesel can best be described as an absolute gem. In typical French fashion it offers one of the smoothest rides you can get, while still retaining the ability to deal with fast swoops and tight bends without upsetting the driver's equilibrium.
After a week with the car you forget how some cars cannot cope with long undulations and potholes at the same time - and we saw plenty of those in the 'Berg! Ride quality is so good in fact that it's hard to believe you're in a car that is aimed at middle management, not the top salary earners.
Handling is dead neutral, thanks to all-round independent suspension, while traction control ensures the powers gets down out of the corners.
Although not the most powerful diesel in its segment, the Renault's unit impresses with its quietness and smoothness while offering bags of low-down torque. Flexibility is a keynote, and this enables one to make good use of the 6-speed manual gearbox.
Yes, we said 6-speed. It has well-balanced ratios, and on a level road it's possible to change up into top gear from as low as 70 km/h and still get a slow - but progressive - pullaway, for even better economy.
We liked the Laguna a great deal. It offers a great combination of luxury and economy, while still retaining the ability to cover long distances quickly and without fuss.
Our only criticism is the lack of a locking boot. For many the Laguna's hatchback makes it a no-no because once inside the car you're inside the load area.
But on the other side of the coin the Laguna has a security system second to none.
Either way, it's no more vulnerable than a 4x4 or station wagon - and there are plenty of people who opt for those!