BMW X3 tyres
Many four-wheel drive systems save fuel by driving on one axle only for most of the time. They only direct power to all four wheels when instructed to by either the driver or the car’s onboard computer system. In contrast, BMW’s xPower system features permanent all-wheel-drive. However, since BMW believes in optimum weight balance between the front and rear axles, in normal driving the xDrive technology directs 40% of the driving torque to the front wheels and 60% to the rear ones.
BMW technology allows this power ratio to be changed in a tiny fraction of a second if the car senses any slipping or change in speed of any individual wheel. On many BMW cars, this feature is supported by Dynamic Stability Control, which can apply braking force to any wheel in a split-second.
Key to these systems is the car’s ability to continually monitor each wheel’s rotational speed relative to the other three. Slippage on any one wheel can immediately be countered by the application of power or braking to the others. A BMW’s computer is able to detect even the smallest change in relative wheel speed so that any such slippage or skid can be detected – and corrected – immediately.
We haven’t mentioned all of this in the interest of public education, sadly! Rather, tyre problems can lead to all kinds of difficulties with this xDrive system, meaning that X3 drivers should always be aware of the condition of their tyres.
A common problem is that the car’s transmission can make sudden, unexpected and frequent clunking or knocking noises. Often tyre wear is the cause, rather than any other mechanical issue. If one tyre becomes irregularly knocked, damaged or worn, it can become ever so slightly different in shape or size to the other three. It will therefore rotate at a slightly different speed relative to the others. The car’s ultra-sensitive onboard technology can then interpret this as a skid or a slip. It will then try to correct the car’s posture through changing the differential or the transmission and driveshaft settings.
Anecdotal evidence suggests that many X3 drivers have either torn their proverbial hair out or run up enormous bills trying to get their transmission fixed in this instance. Instead, the problem is often caused by irregular tyre wear or different types of tyres being fitted across or between axles. Additionally, the car can detect minute tyre differences which are undetectable to the human eye.
Naturally checking your tyres is the obvious starting point for curing this problem. However, the car’s technology is built with the car’s original equipment tyres in mind, and thus the problem is more likely when different tyres have been fitted. In short, the X3 can be very sniffy when it comes to non-standard (ie non-premium) tyres.
In these circumstances, etyres always recommends fitting BMW-approved tyres to an X3. We supply and fit huge numbers of these every week. They may not be the cheapest option, but they offer peace of mind and optimum performance and safety. Dunlop and Pirelli tyres in run-flat form are factory-fitted across almost all of the X3 range, meaning that they tend to be etyres’ best-selling tyres for this car. Dunlop’s Sport range and Pirelli Cinturato, P Zero and Scorpion tyres are available in BMW-approved formats which will suit different X3 models perfectly.