New 80mph speed limit could be for EV vehicles only

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A couple of weeks ago we were very excited at the prospect of being able to drive at 80mph on the motorway. It meant we would be able to get where we wanted to go more quickly, albeit at the cost of a little more petrol.

However, energy secretary Chris Huhne has other ideas. Well, one other idea – that the limit should be for electric vehicles only.

After the proposed limit hike was announced two distinct camps sprung out of the automotive ether.

One camp thinks it's a great idea, citing that large groups of motorists already do 80mph on the motorway already. They also say that that cars are safer now than they ever have been, so crashes won't be as bad as they were when the initial speed limit was plucked out of the sky.

The other camp is not so keen, stating that more pollution will be produced, killing flowers and many children in the process. They also believe it goes against this Government's green agenda.

In response to both arguments Huhne commented on the BBC's Sunday Politics Show that: "You could foresee a situation where it [the higher limit] would apply to electric vehicles, in which case there would be absolutely no extra carbon emissions".

There are a couple of minor flaws in Huhne's case. Firstly, policing such a thing would be ridiculous and difficult in the first place. But that's not the biggest one.

No, by far the largest issue is the fact that going faster in an EV uses more energy.

Ben Rose, editor of milesperlitre.com, talked to Autoblog and, as well as pointing us to thesespeed/energy usagegraphs, put the problem into layman's terms: "If you use 20kW at 70mph but ~30kW at 80mpg that's 50% more energy for just 10mph more speed. However, going down to 60mph would use 50% less energy than you would at 70mph."

So while an 80mph electric car-only limit would cause fewer emissions, it would use more energy overall. And possibly result in a few awkward early-discharges and calls to the AA. Is that really the better solution?