The Bridgestone Potenza RE050A Run Flat is a Max Performance Summer tyre designed to be fitted to Passenger Car Passenger Car Summer Max Performance tyres Tyre review data from 117 tyre reviews averaging 50% over 1,964,052 miles driven. Sorry, we don't currently have any magazine tyre tests for the Bridgestone Potenza RE050A Run Flat Dunlop SportMaxx RT 2 - 93%Michelin Pilot Sport 4 - 91%Vredestein Ultrac Vorti - 91%Goodyear Eagle F1 Asymmetric 3 - 90%Nokian zLine - 89%Hankook Ventus S1 Noble2 - 89% Sorry, we don't currently have any questions and answers for the Bridgestone Potenza RE050A Run Flat. Why not submit a question to our tyre experts using the form below! We will never publish or share your email address To verify you're human please type the word you see above in the box below.Skip to main content area BMW 5 Series review For an alternative review of the latest BMW 5 Series Saloon visit our sister site carbuyer.co.uk Rate your car in our Driver Power customer satisfaction survey
Next month, the fierce battle for supremacy among large saloons between Audi, BMW and Mercedes-Benz will step up a gear with the unveiling of the 2017 BMW 5-series, writes Shane O'Donoghue. But before the covers come off, we've had the chance to spend a day in three different pre-production prototypes of the new four-door saloon on a wide range of challenging roads in North Wales.Because BMW's engineering team comes here twice a year as part of its new model development programme, ensuring that chassis systems all work well in a demanding real-world environment. These roads were chosen because of the camber changes, bumps and corners, but also because the surface has plenty of grip, even when wet. It helps that, even during tourist season, there's little traffic around. That enables consistent testing speeds, though BMW's engineers are quick to point out that these tests are not scientific, more about the less definable 'feel' of the car. And when quizzed, they confirm – as you might expect – that the target for the new 5-series is to retain the current model's comfort level while enhancing the agility and dynamic performance.
To that end, the new 5 Series is some 100kg lighter model-for-model, and the centre of gravity is a few millimetres lower than before too. It's no surprise that the first test car of the day feels agile, as it's a 540i fitted with the optional Variable Damping Control and Integral Active Steering systems. The former allows the driver to bias the suspension toward more comfort or control, though there's a new 'adaptive' setting as in the current BMW 7 Series, too. Integral Active Steering, meanwhile, is BMW's name for rear-wheel steering and on the bucking, twisting B-roads of Wales, it effectively reduces the wheelbase of the 5 Series making it distinctly nimble feeling through tight corners taken at speed. Next up is a BMW 530d, again featuring rear-wheel steering, but here it's paired with xDrive four-wheel drive and BMW's sports suspension option. This lowers the ride height by a further 10mm and features spring rate changes and a stiffer front anti-roll bar. Dry roads mean there’s little reason to call on the extra traction afforded by the xDrive system, but this car is notably tauter than the 540i driven earlier.
It’s never uncomfortable, however. Indeed, Johann Kistler, the new model's Project Director, tells us that each of the three suspension systems (standard or 'comfort', sports and variable) is optimised for the wheel and tyre package that is most likely to be fitted, so in the case of the sports suspension, the optimum wheel size is 19-inch. Kistler is also quite candid about run-flat tyre technology, admitting that BMW was perhaps a little too eager to adopt run-flat tyres at first, but his team has learned a lot since, and indeed the tyre makers have made huge improvements. Now, buyers in the UK and US in particular, want the security of run-flat technology, so BMW develops its cars from the beginning using them. That wasn't always the case. The final vehicle of the day is a BMW 530i. While its petrol engine may not be the most popular in the UK, this car is fitted with completely standard suspension and steering so it's a good benchmark. Driving a variety of roads, mostly twisting, and with plenty of tricky surface changes, this version of the 5 Series remains compliant and composed.
It isn't as fun to drive as the others, and there’s a tad more body roll when pushed, but it still feels good on the road. That’s emphasised later in the day when we surreptitiously retrace the test route steps in a current model BMW 520d M Sport on standard suspension. Not only is there more unwanted body movement through corners in the older car, but its steering also feels lifeless and heavy in comparison. First impressions are that BMW has nailed its brief with the new 5-series, then. All that remains is to compare the finished 2017 car with its adversaries. For all the latest news, advice and reviews from Telegraph Cars, sign up to our weekly newsletter by entering your email here BMW have whole heartedly adopted run-flat tyres across their range (except M cars). The benefits of these tyres seem to boil down to a solitary point; that is, if you have a puncture at high speed (say on the motorway), the run-flat tyre will not explode and cause an almighty crash!
Oh, I suppose an additional benefit (to BMW, as I’m sure that any cost saving was not passed on to their customers) is they don’t have to provide a spare wheel (not even a space saver). Whereas, back on topic, it is almost impossible for me to enumerate the issues I have with run-flat tyres; they cannot be repaired if you have a puncture, they cause increased road (and therefore cabin) noise, they cause a harder ride, they cause poorer handling (which is why M cars have retained non-run-flat tyres), and now they are a contributing cause to fractured alloy wheel rims! Yes, as the tyre side-wall is so hard (strong) to enable it to be driven when deflated, it transmits more impact to the alloy wheel rim. For example, when going over a speed bump a bit faster than intended, or perhaps hitting a pot-hole, not only does it give you an even more jarring ride, but it can (in mine and many other people’s cases) fracture the wheel rim! BMW alloy wheels are not cheap to replace – and it must be replaced because it’s a MOT failure to have a cracked wheel rim.