Остај ти таа работа...На +15 немаат својства како на 7 степени и под...
НЕЛИ??? 
Времево е идеално за летна гума... 
A кај е +15 ?

Иначе гарант досеа некој ова го има постирано ама ако..

When are winter tyres appropriate?
Winter tyres are designed to work when the temperature drops to 7C and below. The tread design and compound formulation are better than summer tyres at these temperatures, so they improve grip, traction, handling and braking. The Met office state the average temperatures between October and March are generally below 7C therefore it makes perfect sense to fit winter tyres.
Can winter tyres be used at temperatures above 7C?
Yes they can, 7C is generally used as the point at which winter tyres start to perform better than summer tyres.
The 7C guideline isn't a 'switch' but rather a tipping point, the further away from 7C the temperature moves (either way) the more effective winter and summer tyres become relative to each other. However winter tyres can be used at temperatures above 7C. Below 7C, braking distances are shorter on wet roads with winter tyres. Even at 30mph there are significant braking benefits when using winter tyres on snowy roads. At 20mph winter tyres would stop the vehicle 11 metres sooner on icy roads.