Run Flat
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.
Fuel efficiency
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.
Wet Grip
An index that determines the overall performance of a tyre on wet pavement. Lettered from
A(highest) to
G(lowest); intermediate options, respectively —
B,
C,
D,
E and
F.
The higher this indicator, the stronger the tyre grips to the wet road, the more efficient and safer it will be in difficult weather conditions. At the same time, it is worth noting that a low grip index does not mean unsuitability for driving in rain or snow — you just need to be more careful using such tyres. Conversely, a high index does not relieve the driver of the need to be careful in difficult weather conditions.
Noise Level
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.
Homologation for
Recommendations of the vehicle manufacturer regarding the ideal tires for a specific car model.
Homologated tires take into account the technical and design features of machine, right down to the factory suspension settings, which helps to reveal the full potential of the "iron horse". Manufacturer-approved tires are recommended to be installed only on the wheels of suitable cars, and in some cases, without the use of homologated tires, machine risks losing its warranty. The sharpening of tires for a specific brand and model of car is indicated by specialized homologation markings.
The shelves of tire stores most often feature homologated tires for the following brands of cars:
Audi(including
Audi RS,
Alfa Romeo,
BMW / Mini,
Ferrari,
Mercedes-Benz(including
Mercedes AMG),
Maserati,
Porsche,
Tesla,
Volvo,
Volkswagen.
