► It’s month eight with our Merc
► A lack of sockets is ruining efficiency
► 25.5mpg from the 442bhp land yacht
What a month! Stuttgart, Vienna, Stuttgart again, Salzburg. In style and comfort, yes. Stressless, no. It’s holiday season, and German autobahn traffic frequently g-r-i-n-d-s to a halt. Why? Not enough road space for too many vehicles, despite a weekend truck ban and rigorously enforced speed limits. Even when your trip kicks off at 5am, by 9am at the latest the trap will likely click shut – Stau! (the German word for congestion). One of these days we’ll be able to lean back and let the car do the brooding. But this is 2015, and when the on-board chips take over, you will likely be out-flocked left and right at an embarrassing rate. True, the S500 does what it can to support the driver: hold the lane even through mild bends, monitor other vehicles with cameras and proximity sensors, scan the road surface ahead for irregularities and pre-condition the dampers accordingly. It’s all very well, but not quite enough to make you totally feel at ease at a felt average speed of 27mph.
The last four weeks passed with almost no plug-ins. At the airport, the six 220V nozzles were regularly taken. At the hotels in Vienna and Stuttgart, the underground car parks were blatantly devoid of charging stations. In Salzburg, the solitary socket had the wrong format. At home, Zoltan was busy painting the garage. No big deal? Well, in combination with a fair amount of motorway driving, the consumption dropped from 31.3 to 25.5mpg. Not bad for a 442bhp 5250mm 2140kg land yacht. But unexceptional for a plug-in hybrid. To get the best out of this system, you want to travel at a reasonably brisk pace and recharge the batteries via lift-off and braking. At ginger velocities, the black box prioritises e-mode, thereby sucking the lifeblood out of the fully charged energy cells in less than 20 miles. I regularly use e-charge which quickly gets the capacity back up to a level that allows us to cruise through town silently like a majestic black whale.
From the driving seat
+ Great for watching telly or listening to Haydn’s Amira (when stuck in traffic)
– Auto cruise control is too kind to stop aggressive lane-changers from plugging the smallest gaps
Logbook Mercedes-Benz S500 PHEV
Engine: 2996cc 24v V6 turbo petrol with plug-in hybrid electric drive, 436bhp @ 5000rpm, 354lb ft @ 1600rpm
Gearbox: 7-speed auto, rear-wheel drive
Stats: 5.2sec 0-62mph, 155mph (electronically limited), 65g/km
Price: €108,945
As tested: €154,890
Miles this month: 1929
Total miles: 11,019
Our mpg: 25.5
Official mpg: 100.9
Fuel this month: €294.60
Extra costs: €0