Currently reading: First Drive: eRuf Concept
Electric alternative to a Porsche 911

What is it?

This is the RUF Concept Model A.

RUF is a small producer of remanufactured Porsches and, not entirely coincidentally, an owner of a large hydro-electric power station. It made this first prototype largely because it felt like it but it is now planning to recruit sufficient staff to make 30-odd electric cars a year.

This prototype lacks some finesse, but it is a prototype, after all. In place of the engine is a compact, 201bhp electric motor that generates 479lb ft of torque from a standstill.

RUF left the regular transmission in place. Having melted some clutches and realising the car will still hit 62mph in 7sec in sixth gear, it now leaves it in sixth and will remove the gearbox from future versions.

Weight reduction might also lead RUF to take out some of the lithium iron phosphate batteries. At the moment they weigh 500kg and occupy the rear-seat space, the boot and some of the engine bay.

They take 10 hours to charge and give a range of up to 200 miles at an average of 50mph. Up the speed and you’ll get more like 100 miles. As usual with electric cars, you can do only what batteries allow. These are as good as it gets, but they’re expensive.

What’s it like?

In feel, the RUF Concept Model A is like a 911 filled with cement. The fine steering remains intact, but the suspension settings are far from production ready: it’s just stiff, without any finesse.

The power comes in cleanly, quietly and relatively strongly, though we weren’t able to drive it quickly.

Should I buy one?

It’s no driver’s car yet, but it has potential. Besides, RUF is realistic. It knows buyers will be minted and have conventionally powered cars too. They’ll commute in the electric 911 and have regular transport to fall back on. The RUF Concept Model A won’t change the world, but it’s not insignificant. And one of its merits is that it’ll save a few people from feeling obliged to drive an electric Smart or a G-Wiz.

Matt Prior

Join the debate

Comments
4
Add a comment…
NiallOswald 27 November 2008

Re: First Drive: eRuf Concept

Casanova wrote:
The point of a gearbox on a car with an engine is to enable the power band to be used at different speeds. On an electric vehicle this is not needed, since there is no power band - all torque is available from rest. The need to keep the engine at a certain rev level is nullified. Hence a single ratio, and a large, heavy, expensive component can be done away with.

Compared to the AC propulsion tzero of 5 years ago (http://en.wikipedia.org/wiki/AC_Propulsion_tzero) the performance and range aren't really spectacular. I'm not convinced it really moves things forward - but it'll be interesting to see what future versions bring.

More usefully than just constant torque, electric motors can also be operated at constant power over a wide speed range (3-5:1 or more) with appropriate design and control, which means at low speed in what is essentially 5th gear, there's as much torque at the wheels as an equivalently powerful petrol car would have in 1st.

The gearbox is also a source of inefficiency, but without putting the motors in the wheels (PML Mini QED for example) it's difficult to entirely eliminate mechanical transmission losses.

TegTypeR 27 November 2008

Re: First Drive: eRuf Concept

Casanova wrote:

The point of a gearbox on a car with an engine is to enable the power band to be used at different speeds. On an electric vehicle this is not needed, since there is no power band - all torque is available from rest. The need to keep the engine at a certain rev level is nullified. Hence a single ratio, and a large, heavy, expensive component can be done away with.

Very true, the removal of the box does contribute to the weight and complexity reduction, but it also increased acceleration times. Surely, the perception of people who are going are going to purchase this sort of car will be one of performance, something the 0-60 time of 7 seconds doesn't suggest.

Indeed at this sort of money, I get the feeling people are going to be overly critical, especially considering competitor vehicles such as the Tesla and their comparative performance (assuming of course the company survives).

My comments regarding "back street" nature of this vehicle merely relate more to the lack of development and apparent professionalism of the conversion, something again that cannot be said of the Tesla. After all it is a 911, so people will perceive it to be just like a 911 with an electric motor, performance accommodation and all.

I know and you know this is not the case but how many potential customers will and how many will be put off by this.

Casanova 27 November 2008

Re: First Drive: eRuf Concept

The point of a gearbox on a car with an engine is to enable the power band to be used at different speeds. On an electric vehicle this is not needed, since there is no power band - all torque is available from rest. The need to keep the engine at a certain rev level is nullified. Hence a single ratio, and a large, heavy, expensive component can be done away with.

As for the rear seats - this is a 911, not a Focus, remember. They are no great loss, and may well return when the final version is packaged. It depends whether it is viewed that its worth taking up weight and space having rear seats, which could be used for batteries.

I think its harsh to describe the development work going into this project as a back-street job. Ruf are clearly very serious about making this car work to a production standard, and their standards are high. I'll be watching them with interest.