Dave Plowman (News) wrote:
In article ,
The Natural Philosopher wrote:
Todays fat soft tyres and larger than needed engines (makes for more
frictional losses at lower power) are very much against the economy.

Under about 55mph the CD makes very little odds.

Leccy cars will score because they can be optimised for whatever driving
speed you choose, efficiency wise. They use nothing apart from cooling
fans when stationary, and instantaneous fuel consumption is as simple to
display as a ammeter in the dashboard

If they decide not to fit vast tyres etc. And of course you don't need too
much heating or cooling which comes nearly free on an IC engine.


Heating comes free. Cooling emphatically does not.

A fairly well insulated electric car could in principle use the few
hundred watts of waste heat to keep it warm. Cooling takes power
whatever you do.


Trouble is luxury cars like this are bought by people who don't care about
fuel consumption - and are unlikely to buy an electric car unless it
matches it in all ways. So sumptuous (and heavy) interior, lots of sound
proofing including double glazing to keep extraneous noise out. 5 kW
heating and equivalent air-con so you don't have to wait for them to take
effect. Etc etc. All of which will not help the range of a battery car.


Agreed. So expect more attention to be paid to things like insulation,
darkened glass, and double glazing.

Also, if lighter car BODIES are made, the need for excessivley large
tyres for grip falls away. There are gains to be made on *all* cars by
reducing weight..