Several factors about tires can impact fuel economy, including tire structure, size, wear, pressure, and conditions of use. Radial tires have lower rolling resistance than diagonal tires. Narrower and lighter tires also have lower resistance. Underinflated tires increase resistance and fuel consumption. While low rolling resistance tires help, other factors like eco-driving style are also important to optimize fuel efficiency.

1. The role of tyres in fuel economy
Five principal features of tyres which have an effect on fuel consumption:
1. Tyre structure
2. Tyre size
3. Tyre wear (technical condition)
4. Tyre pressure
5. Conditions of tyre use
Apart from rolling resistance, every car is subject to the following resisting forces
while travelling:
 aerodynamic forces;
 internal friction;
 gravitational forces;
 inertial forces.

2. To overcome each of these forces, energy is required, and this is provided by the
fuel. A tyre’s motion involves hysteresis (loss of energy in the form of accumulated
heat due to compression of the tyre). Rolling resistance is an effect of this
phenomenon. A very high level of hysteresis means excellent grip, while low
hysteresis means low rolling resistance. It is determined by the viscosity and
elasticity of the materials from which the tyres are made. Hence rolling resistance
has an effect on fuel consumption. The tyres also make a contribution to the
vehicle’s aerodynamic resistance.
Overcoming resisting forces accounts for as much as 35% of fuel usage. Depending
on various factors, rolling resistance makes up between 10% and 70% of these
forces.
1. Tyre structure
 radial tyres have at least 20% lower rolling resistance than
diagonal tyres;
 a smaller quantity and thickness of tyre elements, and a thinner
tread and sides, lead to lower rolling resistance;
 the smaller the mass of the tyre, the lower the rolling resistance
(a lighter tyre can be produced using materials of smaller
thickness, by reducing the quantity of material, and by raising the
profile and reducing the width of the tyre);
 tyre design:
- proper selection of materials;
- mutual positioning of materials;
- quantity of materials used;
- angles of reinforcements and belts.
 the shape of the tyre’s contact patch, the tread pattern and the
materials used in its manufacture (the tread structure makes a
contribution of 60% to the rolling resistance);

3.  the positioning of blocks and other elements of the tread –
optimum design of this part of the tyre reduces its compression
and deformation (a more rigid tyre has lower rolling resistance);
 the rubber compound used to produce the tyre:

- polymers (including butadiene rubbers, natural rubbers and
styrene-butadiene rubbers);
- fillers (soot and silica);
- vulcanizing agent (sulphur).
The greater the number of butadiene parts and the larger the particles of filler (best
is silica with a binder in the form of silanes), the lower the rolling resistance.
 the process of production of the compound – its temperature and
duration.
Not only rolling resistance is important. When making a purchase, choose a product
that will offer good values for a range of performance parameters.
2. Tyre size
 the lower the tyre height, the more rigid it will be, and this means
lower rolling resistance;
 tyre width – a tyre which is narrower by 1 cm has approximately
1.5% lower aerodynamic resistance;
 rim width – changing this may also influence the tyre’s rigidity,
and consequently affect its deformation and rolling resistance.
3. Tyre wear (technical condition)
 the more worn a tyre is, the lower the rolling resistance;

4.  in the case of a worn tyre, its mass decreases and it undergoes a
lesser degree of compression during travel (increased rigidity).
4. Tyre pressure
 low tyre pressure causes greater compression of the tyre and less
squeezing of the tread blocks when in contact with the road
surface;
 a reduction in pressure by 0.3 bar means a 6% rise in rolling
resistance;
 a reduction in pressure by 1 bar means a 30% rise in rolling
resistance, increasing fuel consumption by several percent.
5. Conditions of tyre use
 a higher ambient temperature causes a reduction in rolling
resistance – the reason for this is the increase in pressure and the
attainment of the tyre’s optimum working temperature
(especially in summer).
The impact that tyres have on fuel consumption is a fact, and results from the
influence of many factors. Importance attaches to the tyre’s design and method of
production, the size of the tyre and the conditions of use. We must remember,

5. however, that it is not only the tyres that affect a vehicle’s fuel consumption.
Naturally it is worth buying tyres with low rolling resistance, but it is also necessary to
drive in an economical fashion. Eco-driving experts recommend not warming up the
engine while stationary, accelerating rapidly and dynamically (changing to a higher
gear as soon as possible), and using the engine to brake.
Source:http://www.oponeo.co.uk/
Linkedin: https://www.linkedin.com/pulse/role-tyres-fuel-economy-hessamaldin-abolghassemi-finixx-
tyre-sales-?trk=prof-post