What are low profile tyres?
The tyres are described by such parameters as width, profile height and rim diameter.All of these parameters are interconnected, i.e. if one of them changes, the other ones have to follow.This is caused by the need to keep the total wheel diameter (wheel height) recommended by the car’s manufacturer.Profile height, also known as tyre series, is the ratio between the section height of the tyre (its sidewall) and its section width.
PROFILE (SERIES) = TYRE HEIGHT / TYRE WIDTH * 100%
This dimension is not an absolute value, but is a combination of width and height.For example:according to the formula, the sidewall of a 205/55 R16 tyre will be shorter than in a 225/55 R16 tyre. The total diameter will also be smaller.
What are low profile tyres then?They are tyres, whose sidewall height is small relative to the section width.Low profile tyres are usually used as original equipment in medium and high-class vehicles.Such cars often boast racing performance.Low profile tyres are also used as replacements for factory tyres by tuning enthusiasts.
Low profile tyres:a typical size of a low profile tyre.
What are the characteristics of a low profile tyres?
The tyre industry and market are constantly evolving, just as the entire automobile industry is.The rate of change is high, with a constant stream of new solutions and trends.The whole concept of low profile tyres has evolved over time.
In the 70s, all tyres with a profile lower than 80 were called low profile tyres.Today, however, these values are no longer realistic.A profile of 55 is less and less often considered low.
The 205/55 R16 size is becoming one of the most popular sizes in mid-range cars in Europe.They are often seen in medium-class vehicles without the rim protection, which means that they are no longer considered low profile tyres.
We should bear in mind, that there is a direct relationship between the sidewall height and tyre width.A 185/55 R15 tyre will more readily be labelled low profile than a 205/55 R16, as the former’s sidewall is much lower.
To sum up, we can assume that a tyre with a profile lower or equal to 55-50 can be called low profile, depending on its width.A low profile tyres are also usually equipped with a rim protection flange.
Low profile tyres:profile 15 Kumho Ecsta
What are the lowest series for low profile tyres?
The ETRTO (European Tyre and Rim Technical Organisation) standards defined in 2009 state that 20 is the lowest allowable series, i.e. the 375/20 R21 size. But Nexen and Kumho have shown the first series 15 tyres in the world at the American Sema trade show. In case of Nexen, the N3000 model has a size of 365/15 ZR 24, while Kumho’s Ecsta SPT KU31 is 385/15 ZR 22.
Do low profile tyres wear more quickly?
Each tyre has to be constructed and manufactured to provide usability and durability according to its load bearing and speed indexes for a given size.This is usually achieved by reinforcing the beading and the tread.Theoretically, the lifetime of low profile tyres, if used correctly, should be the same as normal tyres.
However, it can be more susceptible to all kinds of damage, especially when driven at low pressures and with excessive loads.Driving over curbs or other obstacles at high speeds, as well as hitting the curbs with your sidewall may speed up the process.Another factor that makes the low profile tyres wear out more quickly is the driving style and character of the cars they are installed in.Low profile tyres are often sporting products, so the manufacturers try to meet the customers’ expectations by increasing grip at the expense of quicker wear.
Current models more and more often utilise Run Flat technologies, i.e. they allow for driving even when all pressure is lost.This requires additional reinforcement of the sidewalls and shoulders to allow the tyre to keep rolling.
Low profile tyres:profile 15 Nexen tyre
The influence of low profile tyres on the suspension
If a car has had low profile tyres installed as original equipment, all suspension elements are designed to provide proper functioning and durability.
Problems may appear when the steering and suspension are not adapted to larger rims and tyres that are not as good at cushioning.In such cases, low profile tyres may lead to quicker suspension failure.Using low profile tyres also increases the risk of damaging your aluminium rims, commonly used with such tyres.The rim protection will not save the rim if your drive over a hole in the road.
What pressure to use in low profile tyres?
In the case of low profile tyres, pressure is especially important.Overinflation may significantly lower comfort, while underinflation may lead to overheating and irreversible damage to the tyre.That is why the recommended pressure values have to be observed at all times.Some manufacturers, whose tyres are approved for a given vehicle in both higher and low profile versions, recommend a slightly higher pressure for the latter (usually by 0.2 bar), but this is not a rule.The need to increase the pressure is caused by the fact that a smaller volume of air has to carry the same load.
Low profile tyres:a low profile tyre enhances the look of your car.
Low profile tyres: pros
The most readily visible advantage of low profile tyres is that they look better.
Low profile often means that larger rims and wider tyres have to be used, which can be beneficial to braking and cornering on dry roads.
Low sidewalls also increase the rigidity of a tyre, which is especially important when cornering at high speeds, especially on smooth surfaces.
Low profile tyres provide better grip, and thus better control and predictability.Side swaying is significantly less noticeable.
Low profile tyres: cons
Lower driving comfort is among the main drawbacks of using low profile tyres.This includes both mechanical (shock) and acoustic (noise) comfort.Lower sidewalls and increased rigidity make every unevenness in the road more noticeable than on comparable tyres with a higher profile. Increased tread stiffness also means smaller contact patch on uneven surfaces, which may hinder grip.
Low profile also usually means increased width.This in turn may generate more noise.
Low profile tyres installed in cars that have not been adapted for stiffer wheels by the manufacturer may have a negative impact on suspension wearing.Moreover, changing the wheel diameter by 5 mm will require you to readjust the headlights.