Mid-life facelifts of largely successful cars are seldom dramatic. Leave that to the next all-new model, unless your last all-new model was a pig. Luckily for Renault there was nothing pork-like about the second generation 2003 Scenic and Grand Scenic, so 2006 visual tweaks of both are minor.

Changes include a new grille with a more pronounced ‘V’ shape in keeping with recent sister Renault products; redesigned bumpers back and front (now optionally body-coloured – though with some paint finishes they still look better in plain grey); the fog lamps have moved further out to the edge of the car on each side; and there are some twiddles to the headlamps.

Inside, new chrome bits surround various controls, handles and vents on Dynamique trim and upwards, and Authentique trim gets body-coloured door mirrors and door handles. There are also some new options first seen on larger Renaults such as flip-down ‘Sleep Safe’ headrests to protect children’s necks, and Bluetooth hands-free and iPod docking kits.

All smart stuff, but none are standard.

The bigger news is the option of a five-seat version of the Grand Scenic and a range-topping 150PS 2.0 dCi diesel engine with an auto gearbox option – both Scenic ‘firsts’.

The five-seat Grand Scenic is for those who seldom use seven seats but want more room for luggage space. It offers a 533-litre minimum, beating the basic Scenic’s 406 and the seven-seat Grand’s 475 with third row folded flat. The 1960-litre maximum also trumps the Scenic’s 1840 and the seven-seater’s 1920.

The five-seat Grand Scenic’s extra space is gained by a slightly lower load floor height, two draws under the second-row seats (as there are no third row seat passengers needing footwell room) and two shallow compartments that will each take a slim laptop bag under the boot floor (as there is no third row of seats to stow away).

Five-seat versions are £250 cheaper than the seven-seaters across the range and offer better second row headroom, but according to Topcalc figures, the cost per mile will be within a penny in most cases. Renault believes the five-seat Grand Scenic could amount to 25% of the 30,000 annual UK sales total.

Slightly more niche but still important is the new flagship diesel engine. The 150PS 2.0-litre unit gives Renault the chance to compete in diesel terms in this segment for the first time against Ford’s S-Max (136PS 2.0), Vauxhall’s Zafira (150PS 1.9) and VW’s Touran (140 and 170PS 2.0). It feels as punchy as all but perhaps the 170PS VW engine and it is noticeably smoother and quieter than the more raucous Zafira unit.

The six-speed manual version that was unavailable to test will be most fleets’ choice over the new auto option. It has superior mpg (48.7 vs 39.2), CO2 emissions (154 vs 190g/km) and will be eight BIK tax bands lower (23% vs 28%), but the new six-speed sequential auto gearbox is still an important development. According to Renault, Motability customers represent some 30% of the mini-MPV market and diesel is the fuel of the moment, so a diesel auto makes a lot of sense. With only two diesel auto mini-MPV rivals right now in the Touran and Zafira (Ford’s new oil-burner auto is not due in its S-max, C-max and Galaxy until next May) Renault has joined an exclusive club.

There are two autos to choose from – a four-speed on the 130PS 1.9, which is a bit basic, and a six-speed sequential dash-mounted unit allied to the 150PS 2.0. The latter makes driving a doddle despite the lack of paddle-shift, and is actually quite fun in sequential mode. The carried-over 111PS 1.6 petrol is still expected to be the best-seller and now gets a six-speed manual to replace the previous five-speed. It’s decent if noisy, and needs to be worked hard even with only two passengers aboard.

All cars benefit from sharpened steering that makes the Scenic much more precise on manoeuvring than before, if not quite up to C- or S-max quality.

On whole-life costs, 35.8p loses out to the Touran (33.8p) and Zafira (34.4p), but is still competitive. With the engine and transmission additions plus Renault’s claim to be keeping a closer than ever eye on quality control, the French marque looks to have done enough to keep its segment pioneer right up there until the all-new Scenic III in 2009.