S-class gears up

Now that nearly every prestige maker has a penchant for six-speed autos, Mercedes has been looking off the pace with just five cogs. But when it comes to Teutonic muscle flexing, merely matching your peers isn’t good enough. Enter, then, the 7G, the world’s first seven-speed automatic, now fitted to most of the company’s V8-engined models.

But does the world really need seven forward gears? And, more crucially, the two reverse gears this new box provides? Mercedes reckons it’s justified in the name of added pace and enhanced economy - at 70mph the engine of our test S500 L now spins at 800rpm less than the outgoing version.

It will also handle more torque than the existing ’boxes, though still not enough to cope with the twisting power of the company’s most powerful AMG models.

Slicker changes are also on the menu, courtesy of a new system billed as ‘sliding multiple downshift’. Essentially this allows for overlapping gearshifts, lining up the next shift before the current one is completed. Not too far away, in fact, from the principle behind Audi’s excellent DSG system.

On the road it works well, too. There wasn’t a lot wrong with the shift quality of the old-tech ’box but this one moves the game on further. Cog swaps are crisper, quicker and even less obtrusive when you’re churning through the three lowest gears. It means, at least, that the Merc’s changes are now as seamless as a BMW 7-series driver will experience - the current auto ’box benchmark.

You should also feel the benefit at the pumps. More relaxed cruising and more ratios to play with means that the S500’s combined fuel consumption has increased from 23.7 to 24.8mpg, with similar improvements for the other V8 Mercs. Spend a long time in the outer lane with a light throttle and you should do a lot better than that.

So all good news, then? Not quite, no. At lower speeds the electronics now have an annoying habit of holding on to gears a mite longer than necessary, and on half-throttle lunges it hunts for gears too often.But overall, these are minor flaws compared to the benefits. The world’s best luxury car just got a bit better.

Chas Hallett

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