A technology that allows the tyre to maintain its performance even being flat. If a
conventional tyre fails after a maximum of a couple of kilometers with a loss of pressure, then you can drive several tens of kilometers on
RunFlat tyre without any problems — this is usually enough to get to the nearest tyre service. Similar properties are achieved due to the reinforced structure, particularly the increased rigidity of the sidewalls. Different manufacturers may use names other than Run Flat for this technology, such as Flat Run or Zero Pressure.
We note separately, that tyres with this feature can only be used on vehicles equipped with a tyre pressure monitoring system. Without such a system, it is likely that the driver will not notice tyre damage immediately — and this is fraught with several unpleasant consequences at once. Firstly, you can miss the time needed to correct the situation — as a result, the resource of a flat tyre may not be enough to normally get to the workshop or service station. Secondly, driving on a run flat tyre requires slowness and special care, driving in a normal style on such a tyre can lead to loss of control.
The rolling resistance rating that the tyre corresponds to. The higher this figure, the lower the resistance, the less fuel is spent to overcome it and the more economical the tyre is. Efficiency indices are denoted by letters of the Latin alphabet in descending order of efficiency:
A(highest efficiency),
B,
C,
D,
E,
F,
G(lowest efficiency).
With other things being equal, more economical tyres tend to cost more, but the difference is offset by fuel economy.
The average noise level created by a tyre while driving. The lower this indicator, the more comfortable this model will be, the less additional noise it will create.
Note that EU rules provide 3 categories of tyres in terms of noise.
“Quiet” are considered models with an index of up to 68 dB,
“medium” — 68 – 71 dB,
“loud” — 72 dB and above.