FUSION Issue 3-2026 DIGITAL - Flipbook - Page 21
EVs
Composites can take significant
mass out of a car. The electric
vehicle industry has spent the last
five years putting it back in.
Here is a fact that sits awkwardly alongside
everything this magazine usually celebrates
about lightweighting. Some of the most
advanced electric vehicles on the road today
are also among the heaviest vehicles ever sold
to the public. Several electric pickup trucks
now on the market weigh in excess of 8,000
pounds, carrying battery packs exceeding 200
kilowatt hours. That is enough stored energy
to power a typical home for roughly a week,
packed into a single vehicle, purely so that
vehicle can achieve a motorway range that a
modest petrol saloon managed decades ago on
a single tank.
This is not what anyone in composites
or lightweight materials expected the EV
transition to look like. The industry has spent
years explaining, correctly, that every kilogram
removed from a vehicle reduces the energy
required to move it, extends range, and reduces
battery demand. That argument remains true.
What has changed is what manufacturers have
chosen to do with the weight savings once
they achieve them.
Where the savings actually go
Large-scale aluminium casting techniques, often
referred to as gigacasting, have genuinely reduced
the weight of EV chassis structures compared to
traditional stamped steel assemblies built from
hundreds of separate parts. That part of the story
is real and well documented. The complication is
what happens next.
In several prominent vehicle programmes, the
weight saved in the chassis has been reallocated
rather than retained. Manufacturers have used the
freed-up weight budget to fit larger battery packs,
chasing bigger advertised range figures rather than
a genuinely lighter, more efficient vehicle. The
lightweighting still happened, in an engineering
sense. The car simply does not get any lighter,
because the saving was spent elsewhere before it
ever reached the showroom floor.
There is a second factor compounding this.
Lithium iron phosphate battery chemistry,
increasingly the default choice across the mass
market for its lower cost, improved safety, and
longer cycle life, is also heavier per kilowatt hour
THE WEIGHT NOBODY
WANTED TO SAVE
of stored energy than the nickel-based chemistry
it is steadily replacing. As manufacturers shift
toward LFP for sound commercial and safety
reasons, the weight of an equivalent-range
battery pack tends to increase, not decrease.
Why this matters for
composites manufacturers
None of this undermines the case for
lightweight materials. If anything, it
sharpens it considerably. In a market where
battery chemistry is trending heavier and
manufacturers are inclined to spend weight
savings on bigger packs rather than banking
them, the structural and body components
built from composites and advanced
lightweight materials become the only part
of the vehicle where genuine, non-negotiable
mass reduction is still happening.
The vehicles bucking this trend illustrate
the point clearly. Manufacturers pursuing
what might be called a genuine lightweight
philosophy, rather than a brute-force approach
built on ever-larger battery packs, are achieving
significantly better efficiency per kilogram of
battery carried. The difference between these
two approaches is not a matter of degree. It is
closer to a different design philosophy entirely,
and composites sit at the centre of which path
a manufacturer is able to take.
For composite manufacturers and suppliers
working in the automotive space, the implication
is straightforward. The pressure to deliver
genuine weight reduction in the structures
and components composites can address has,
if anything, increased, precisely because so
much of the rest of the vehicle is moving in the
opposite direction. Every kilogram a composite
component saves now carries more
relative importance than it did when battery
packs were smaller and chassis weight reduction
was being banked rather than spent.
A market correcting itself
There are signs the industry recognises this
tension. Solid-state battery technology,
still some years from full commercial scale,
promises significantly higher energy density
and therefore lower weight for equivalent
range, which would ease the pressure that
LFP adoption has created. In the meantime,
manufacturers pursuing efficiency-led design,
rather than range-led marketing, continue to
demonstrate that a genuinely lightweight EV
remains both possible and commercially viable.
The honest takeaway for the composites
sector is this: the case for lightweighting was
never really about a single number on a spec
sheet. It is about every gram of unnecessary
mass a vehicle does not have to carry,
regardless of what happens elsewhere in
the design. As long as battery chemistry and
manufacturer incentives keep pulling vehicle
weight in the wrong direction, composite and
lightweight material suppliers remain one of
the few parts of the automotive supply chain
still pulling firmly the other way.
“ In a market where the
battery keeps getting
heavier, the structural
components built
from composites are
the only place genuine
weight reduction is still
guaranteed to happen.”
dtc-uk.com
20
