Why overweight electric cars are not the answer

Not too far into the Austrian GP at the hilly Red Bull Ring, it was noticeable how many rolls of tread-compound ‘rubber’ had already been ground off the incredibly fast but amazingly hefty competing cars’ tyres. Of course such off-line ‘marbles’ are a common sight. Most enthusiasts never even give them a passing thought, unless some superstar gets off onto them, slithers off circuit and eventually finds something hard to hit.

Generally, the marbles accumulate around every circuit through a lengthy, flat-out race, and only a small percentage will ever be squeegeed up by the worn tyres of the finishers as they seek to pick up a safety margin of additional weight in case post-race scrutineering proves uncomfortably tight.

Studying those marbles and thinking about the accumulation one can also see in the gutters of any public road today, reminds me of a daunting pollution statistic I’d only recently learned. I’m not particularly a so-called greenie, but according to Friends of the Earth the UK dumps some 19,000 tons of ‘tyre fragments’ into our waterways each year, simply rain-washed there via the roadside drains. That drain-wash then accounts for some 30% of all microplastics polluting the world’s oceans. Other sources claim 78%, and six million tons per year…

Now tyre wear rises with tyre stress and temperature. The bigger and heavier the vehicle the worse its given tyres will suffer. This leads the thought process back to Formula 1 car size (i.e. these days great and gormless) due largely to FIA regulation minimum weight. That limit of course has been dictated largely by modern safety systems – which have certainly saved many from death or disablement. From Lotus 25/33 days (yes, here old fartism intrudes) when minimum weight was 450kg (992lb), 60 years later the limit is 800kg (1764lb) while for next year’s bright new dawn the new F1 minimum weight is reducing to 768kg (1693lb).

“Many EVs’ battery weight exceeds that of the Rasa complete”

But never mind the minimal traffic volume of F1, nor of worldwide motor sport per se. What is really playing a major part in screwing up our families’ futures is the environmental damage created by grossly overweight modern road vehicles – which these days includes not just ever-heavier commercials of all kinds but outrageously obese battery-packed electric cars (yes, that’s right) for which so many ‘green’ claims have been made by producers and politicians alike.

I recently drove – and very much enjoyed driving – not a BEV (battery electric vehicle) but an FCEV (fuel cell electric vehicle) which, if only sufficient funding could be secured, seems an eminently sensible forerunner to an entirely different form of ‘motor industry’. It could tackle global climate and environmental threats in an enterprisingly fresh way, even to replacing major motor industry’s traditional retail-pricing methodology at square one.

The FCEV I drove is a hydrogen-fuelled Rasa prototype from Hugo Spowers’ Riversimple company. With a carbon composite chassis structure clad in moulded carbon/flax bodywork it’s a pretty little thing which offers multiple advantages compared to the big industry approach.

All up it weighs 655kg (1444lb). Its almost motorcycle profile tyres are only 4½in wide exploiting its minimal weight by minimising road contact and wear. Its body style emphasis has been on aerodynamic efficiency which means minimising energy-burning drag.

While many major manufacturers dress up their EVs with tail diffuser surfaces and waffle about ‘F1-style ground-effect’ suction, the Riversimple concept turns that on its head. Many EVs’ average battery weight exceeds that of the Rasa complete. Instead its scrupulously clean undersurface rises into a tail diffuser, but with such lofty ground clearance beneath (plus within-the-wheelbase sill tunnels each side for the best possible unobstructed throughflow of air) that it slashes tyre-wearing suction-induced download, and thereby minimises associated aerodynamic drag.

Riversimple has built a number of prototypes. All use a hydrogen fuel cell, generating electricity to feed capacitors, powering individual four-wheel drive motors, presently mounted outboard on the hubs. These motors are shortly to go inboard, chassis mounted with half-shafts providing four-wheel drive. That move will improve unsprung weight, a critical factor with such a lightweight unit. But even in present form the little car – which looks faintly reminiscent of an early ’60s Le Mans Alpine-Renault – really feels nimble.

It’s the diametric opposite of the battery-laden heavyweights we see increasingly on our roads – and even though the EVs’ early weaknesses of being cars which very expensively carry batteries not very far, not very fast, the infrastructure to recharge them (so slowly) remains a costly future dream.

To replace 20 fuel pumps at a motorway services to support the current number of cars would need 120 120kW fast chargers requiring a 14.4MW substation – matching the average consumption of 32,000 UK homes. Then consider EVs’ scrapping legacy of lithium, cobalt and nickel toxicity – plus, of course these heavyweight vehicles’ efficiency as generators of immortally pollutant tyre marbles – and there just has to be a better way.