Range Extender takes up the Challenge

MAHLE Powertrain recently took part in the Bertha Benz Challenge, visiting several landmarks across southern Germany and culminating in demonstration laps at the Hockenheim race circuit.

MAHLE Powertrain recently took part in the Bertha Benz Challenge, visiting several landmarks across southern Germany and culminating in demonstration laps at the Hockenheim race circuit.

The MAHLE Range Extender demo car attracted a great deal of interest and ran faultlessly throughout the 3-day event.

Dr Mike Bassett, Head of Hybrid Product Group, takes up the story:


Bertha Benz Challenge 2013

On the 5th August 1888, without telling her husband (Dr. Karl Benz) and without permission of the authorities, Bertha Benz drove with her two sons, in one of the newly constructed Patent Motorwagen automobiles, to visit her mother. In completing the return journey from Mannheim to Pforzheim, Bertha Benz became the first person to drive an automobile over any real distance. Motorized drives before this historic trip were merely very short trial drives, returning to the point of origin, made with mechanical assistants. This pioneering tour covers a distance of about 106 km each way. This historic journey heralded the beginning of the age of the automobile and served to prove the viability of this new technology.

The Bertha Benz Memorial Route comprises of 194 km of signs indicating the original route taken from Mannheim via Heidelberg to Pforzheim and back. The Bertha Benz Challenge is an annual event held for vehicles with alternative drive systems (electric and hybrid vehicles, hydrogen and fuel cells vehicles, CNG and LPG, Biofuels, or any other extremely economical and environmentally friendly technology). It occurs over three days and follows the Bertha Benz Memorial route. This year the Bertha Benz Challenge started at the Frankfurt Motorshow (Internationale Automobil-Ausstellung – IAA), which is the world's largest motor show and is held biennially in Frankfurt.


Vehicles on display at the IAA showVehicles convene at Mannheim Castle


The MAHLE Range Extender (REx) demonstrator vehicle took part in this year’s Bertha Benz Challenge and had to be shipped overnight from Paris, where it had spent two days in the hands of two French auto makers for demonstration drive events, to be in Frankfurt in time for the start of the event. The MAHLE REx demonstrator vehicle is essentially an electric vehicle that also has an on-board electrical generator (range extender) which can be activated during driving to enable the vehicle to continue to be used even when the battery is depleted. The MAHLE range extender engine has been designed specifically to be a low cost unit with a small package volume and good NVH attributes. It is a 30 kW, 900 cc, twin cylinder, 4-stroke gasoline engine which features a fully integrated axial flux generator, housed within the engine’s crankcase, resulting in a lightweight, small and cost-effective solution. Another key feature of the engine is the oil system which enables the engine to be installed vertically or horizontally for increased package flexibility. The resulting demonstrator vehicle achieves an electric operating range of about 70 km and with a 25 litre fuel tank can cover a total range of 500 km between refuelling and recharging events. The vehicle achieves a CO2 figure of less than 45 g/km over the European test cycle.

For the first morning of the Bertha Benz Challenge (Friday 13th September) all of the vehicles competing in the event were on display at the IAA show. During the afternoon the vehicles were driven from Frankfurt to Mannheim in convoy to begin the drive along the memorial route the next morning. That evening the competitors visited the Karl Benz Museum in Mannheim and saw the actual car used by Bertha Benz on her historic journey and then laid a wreath on Dr. Benz’s memorial.

The 2nd day of the Bertha Benz Challenge was completed under heavy skies and very damp conditions. Despite the very heavy rain the MAHLE car continued to perform faultlessly. The vehicles travelled from Mannheim to Heidelberg Castle and then on to Bruchsal Castle. Finally the cars arrived at Pforzheim, where they were parked in the centre of the shopping area for the night. They were greeted at Pforzheim by a large and enthusiastic crowd and the drivers were interviewed by the local press. For the last leg of the 2nd day the MAHLE crew (Dr. Bernd Mahr and Mike Bassett) were accompanied by a freelance journalist who contributes to Auto Motor und Sport magazine amongst others.


The event start on day 2 in Mannheim





MAHLE REx demonstrator in the grounds of Heidelberg CastleEnd of day 2 in Pforzheim


During the 3rd day of the challenge the vehicles were driven from Pforzheim to the Hockenheimring, were they did a number of demonstration laps around the circuit during the lunchbreak of the Hockenheim Classics event. Dr. Mahr, CEO of MAHLE Powertrain Limited, was at the wheel of the MAHLE demonstrator car for these laps, but unfortunately, due mainly to the damp conditions, he was not able to beat the lap record set by Kimi Räikkönen in 2004. Finally, from the Hockenheimring the cars continued to Mannheim castle for the finish of the event. The MAHLE REx demonstrator completed the 310 km route without any issues and received a significant amount of interest along the way.

You tube video of the event: click here


“Was I fastest?” Dr. Bernd Mahr at the Hockenheimring