MT Auto Parts Blog | Expert Tips for BMW enthusiasts on BMW Parts, Accessories, Engines and More

Photo by Benjamin Brunner on Unsplash Run-flat tyres divide BMW owners more reliably than almost any other topic. Some swear by the peace of mind they offer; others have switched them out at the first opportunity and never looked back. Both positions have genuine merit, which is why understanding exactly how they work and what the honest trade-offs are matters before you are standing in a tyre centre deciding on pressure. What Are Run-Flat Tyres? A run-flat tyre uses a reinforced, self-supporting sidewall, considerably stiffer than a standard tyre's, that can carry the vehicle's weight even when the tyre has completely lost air pressure. BMW's run-flat specification, known as a Self-Supporting Runflat (SSR), allows continued driving at up to 50 mph for up to 50 miles after a puncture, giving the driver time to reach a garage rather than being stranded at the roadside. This operating limit, 50 mph for 50 miles, is the key figure to remember after a pressure loss. Exceeding e...

Photo by Yoab Anderson on Unsplash The BMW Start-Stop system ​ is one of those features that most BMW owners barely notice when it is working. The engine cutting out smoothly at the lights and restarting the moment you lift the brake is almost imperceptible in normal driving. But when it stops working correctly, or when it seems to stop working for no obvious reason, it can be genuinely confusing. The system depends on a surprisingly large number of conditions all being met simultaneously, and a single sensor reading outside its expected range is enough to disable it entirely. This guide explains how the BMW start-stop system actually works, why it disables itself, sometimes legitimately, sometimes because something has genuinely failed, and what the most common faults are and what they usually point to. How the BMW Start-Stop System Works BMW introduced start-stop technology as part of its EfficientDynamics programme, with the system first appearing in a production BMW in 2007. The i...

Photo by Oleg Bilyk on Unsplash Winter is the time when deferred maintenance stops being theoretical. A battery that was borderline in October is flat in January. Tyres that scraped through last MOT will have noticeably less grip on a wet roundabout in December. Wiper blades that smeared a bit in summer become a visibility problem in frost. A BMW is no more immune to this than any other car, and in some respects, with run-flat tyres, a complex electrical system, and xDrive's demands on the drivetrain, it gives you slightly fewer second chances when something is marginal. Here is what to check before the cold properly arrives. Battery The battery is the single most common cause of winter breakdowns in the UK, and it is also the most predictable. Cold temperatures reduce the chemical efficiency inside the battery significantly. A weak battery that functions adequately in September will sometimes fail to start the car on a January morning below zero. BMW's own seasonal check guida...