Emissions from tyres
"In his letter “Light on the brakes” Andy Brown correctly identifies that an electric vehicle’s regenerative braking leads to lower dust emissions from the friction brakes (Your Voice, Professional Engineering No 8, 2019).
"The picture becomes a little more complicated when considering emissions from tyres. His economical use of the brakes will certainly help, but this is something that all drivers, even those with internal combustion engine powered cars, could do. Things become more complicated still when we consider that electric cars tend to be considerably heavier than their internal combustion engine counterparts and also considerably more capable of lighting the tyres up at the traffic lights.
"I suspect that Mr Brown doesn’t drive a Tesla, but even a humble Nissan Leaf will out drag most internal combustion engine powered cars up to 40mph should the owner choose to. Unfortunately the greater weight and acceleration performance of EVs leads to more emissions from the tyres not less."
Adrian Griffiths, Henley in Arden
Recover the energy
"Dr Jody Muelaner raises the valid issue of particle pollution from tyres, brakes and roads (“Why electric cars won’t stop air pollution,” Professional Engineering No 7, 2019).
"While it is true these still exist with electric cars, by planning ahead and using gentle braking when possible it is realistic to make most retardation by recuperation of energy back to the battery. As well as improving range and energy cost, this will save brake pad and disc wear. Probably tyre wear a bit too.
"I am only three months into electric car ownership, but have set myself an objective of six years’ life from the brake consumables."
Ian Kay, Solihull
"Over the last two years, I have followed the efforts being made to fill the 60,000 engineering vacancies in the UK.
"I am now 80-years-old and, having spent 15 years in industry, completed a BEd and had a career teaching physics and chemistry. I am a member of the University of the Third Age. Last term I enjoyed the Science for Grandchildren course.
"Two issues concern me. First, the word ‘elements’ does not appear in the key stage one and two science curriculum. The basic building blocks of the universe do not appear.
"Second, budgeting is not an included requirement in the primary maths curriculum. This is a necessity if personal debt is to be reduced, together with poverty and its connected mental health problems.
"On the first issue, the Periodic Table names the elements and gives their symbols (useful in both letter formation and phonics practice). Many elements are already known and in common use – in the human body, food, metals etc. A good Periodic Table also identifies the solids, liquids and gases. The large number assigned to each one gives a comparison of mass.
"A Periodic Table of Elements should pervade every classroom in primary and secondary schools. Our pre-school Scallywags nursery is including an Element Basket, here in Girton. The Periodic Table is a source of integration within the whole curriculum."
Philip Noble, Girton, Cambridge
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Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.