Tire marking: 195 - tire width in millimeters; 55 - tire profile height as a percentage of its width; R - designation of a tire of a radial design; 15 - tire fit diameter corresponding to the fit diameter of the wheel rim; 85 - load capacity index; V is the speed index.
Structural elements and main dimensions of the tire: D - outer diameter of the tire; H is the height of the tire profile; B - tire width; d - landing diameter of the tire; 1 - frame; 2 - breaker; 3 - protector; 4 - sidewall; 5 - board; 6 - bead wire; 7 - filling cord.
The size of tires used on a car is closely related to the size of the wheels used. Chevrolet Lacetti is equipped with low-profile tubeless tires with the following sizes: for 14-inch wheels - 185 / 65R14, for 15-inch wheels - 195 / 55R15.
The tire size is deciphered as follows: 185 (195) - tire width in millimeters; 65 (55) - the height of the tire profile as a percentage of its width. If the profile height of a tire is 65 percent or less, the tire is called a low profile tire; R - designation of tires of a radial design; 14 (15) - tire diameter in inches (matching the wheel rim diameter).
Tire markings must contain designations of the load index (numerical) and speed index (latin letter). For Chevrolet Lacetti tires, the load index must be at least 85 (which corresponds to 515 kgf), and the speed index is not lower than T (190 km/h).
The tire speed index indicates at what maximum speed you can drive on these tires.
This speed should be slightly higher than the maximum speed of the vehicle.
Additional designation of a radial tire (RADIAL) tubeless (TUBELESS) It is not recommended to use tires of obsolete designs on the car: diagonal (the exception is the spare wheel "dokatka" with a diagonal tire), as well as chamber.
Although such tires are already quite rare, it is still necessary to check when buying whether there is an R letter in the tire marking (or the word Radial), as well as the word Tubeless, meaning that the tire has a tubeless design.
Usually a new car is sold with summer tires. If you intend to operate the car in winter, be sure to purchase a set of winter tires (before the start of winter, car dealers often offer their customers a set of winter tires as a gift). It is undesirable to rearrange sets of tires on a single set of wheels every season: the tires deteriorate from this. It makes sense to purchase a separate set of wheels for winter (or summer) tires.
It is best to store the tires removed from the wheels in a standing position, and the tires mounted on the wheels - hung on wire hooks or stacked.
It is not necessary to create special conditions for storing tires; it is quite possible to store them both in the garage and on the balcony of a city apartment. The main conditions for reliable storage are the absence of nearby heat sources, direct ultraviolet radiation (sunlight), and adequate ventilation to prevent dampness. Do not allow tires to come into contact with oils, greases, paint, fuel and other chemicals.
When the car is parked on wheels for a long time, it is necessary to check the pressure in its tires at least once a month, and also move (roll over) vehicle for a short distance so that the tires change their position, otherwise they may be deformed.
It is unacceptable to park a car for a long time on a completely flat tire: its internal structure is broken and its strength is reduced.
The service life of tires is usually not specified by the manufacturers of the tires themselves and automobiles, since it strongly depends on the operating conditions and driving style. The average tire mileage is approximately 40-50 thousand km (with careful operation, it can reach 70-80 thousand km). Tire wear is assessed, first of all, by the depth of the tread grooves, which should be at least 1.6 mm. Also, the tire wear limit can be determined by indicators - transverse protrusions in the longitudinal grooves of the tread. When the height of the indicator lug equals the height of the tread, this will indicate that the tire is worn out and should be replaced.
Uneven tire tread wear (more severe wear on one side, only the central part of the tread or, on the contrary, only the side parts, "spots" (local scuffs), stepped wear of tread blocks, destruction of individual blocks) testify to the careless attitude of the driver to the tires and to the car as a whole: aggressive driving with wheel slip when starting from a standstill, braking with wheel lock, fast driving on roads with poor coverage, not brought to normal (insufficient or excessive) air pressure in the tires, vehicle overload, etc. Also, uneven tire wear may indicate a malfunction or wear of the vehicle suspension elements, causing a violation of the wheel alignment.
It is dangerous to operate tires with local swellings on the sidewalls ("hernias"), as well as with deep damage to the tread or sidewalls, exposing the cord.
Such tires should be replaced immediately with new or used tires that are still fit for use.
Do not save on your own safety and do not repair tires with cuts and tears longer than 2 cm.
The car uses tubeless tires. It is forbidden to install a tube in such a tire, even for temporary sealing of a puncture or cut. The tube may collapse while driving, resulting in an immediate and sudden drop in tire pressure and may result in an accident.
On the Chevrolet Lacetti, of course, you can install not only wheels and tires of regular sizes, but also others, for example, wheels with an increased diameter (16 inches or more) with matching low profile or even extra low profile tyres. It is important that at the same time the main parameters of the wheels (offset, PCD and outside tire diameter) were exactly the same as the regular wheels, otherwise installation would be impossible. The width of the wheel with the tire should also not exceed a certain value, otherwise the wheel will touch the suspension and body elements, especially when turning the car. If it has a reduced overhang, then this can be avoided, but the load on the hub bearing will increase significantly, which is also bad.
Spare wheel - "stowaway" car Chevrolet Lacetti The car is equipped with a spare wheel - "stowaway". This wheel has stock seats (number of fixing holes, PCD and DIA), but features reduced tire height and width to take up less boot space. Parameters of "dokatka": 125 / 70D15. On this wheel, you can move at a speed of not more than 80 km / h. It is advisable to replace the "stowaway" with a repaired or new standard wheel as soon as possible.
Marking of the tire of the spare wheel - "dokatka": T - the shape of the wheel rim; 125 - tire width in millimeters; 70 - tire profile height as a percentage of its width; D - designation of a diagonal tire; 15 is the tire fit diameter corresponding to the fit diameter of the wheel rim.
Marking of the wheel-"dokatki": 4 - rim width in inches; T - designation of the rim shape; 15 - the landing diameter of the wheel corresponding to the landing diameter of the tire.