TÜV SÜD: Effective windscreen wipers enhance visibility and safety
TÜV SÜD: Effective windscreen wipers enhance visibility and safety
The average German driver buys new windscreen wiper blades every two years. Are your current wipers still performing reliably, or do you need new blades to restore visibility? As winter approaches, this is the time to take a close look at your windscreen wipers. TÜV SÜD has some practical tips.
Although windscreen wipers operate directly within the driver's field of vision, they often fail to get the attention they deserve given their important contribution to safety, ensuring clear road visibility in poor weather. But they generally only seem to merit a closer look when the windscreen no longer comes up sparkling or when they begin to squeak irritatingly at every sweep. By the time they reach this stage, good wiper blades will already have cleaned an area equivalent to a dozen football pitches. "The primary wear factors for windscreen wiper blades are not only sheer driving distance and driving in the rain; in fact, summer heat and ultraviolet rays wreak the most damage“, says Eberhard Lang, TÜV SÜD's car expert. Insects also cause damage to wiper blades; the chitin their bodies are made of is extremely hard and can actually rip microscopic notches in the rubber. It follows that changing the blades before winter is a logical step.
Cleaning: Poorly functioning blades need not necessarily require replacement; sometimes careful cleaning can work wonders. A household nailbrush is excellent for this – remember to brush across the rubber, not along it! The blades are easiest to clean when dismantled. A solution of washing-up liquid or car shampoo is usually enough to give good results, although a piece of kitchen towel and undiluted anti-freeze for windscreen washer systems may be needed to remove stubborn dirt. Solvents like thinner or petrol should not be used, as they will destroy the thin graphite compound layer coating high-quality wiper blades – and maybe more. The rubber of the blades itself will also suffer from incorrect cleaning methods, which may even render them permanently unusable. Smears need not be the fault of the wiper blades, incidentally; the windscreen itself may be the cause of the problem. Residues of wax or silicone from car washes or other treatments can be removed with glass cleaner or special cleaning cloths.
Changing: TÜV SÜD's expert Eberhard Lang advises that annual replacement is a good rule of thumb for conventional windscreen wipers. However, the expert also recommends choosing well-known brands; their higher price is usually compensated for by their longer life and improved performance. Although many manufacturers emphasize that their wiper blades are of natural rubber, synthetic rubber is not a bad choice for windscreen wiper systems. The optimum product is a dual wiper with the top section made of synthetic rubber and the blade next to the windscreen of natural rubber; these wipers are also less susceptible to summer heat.
Upgrading: Today's cars are often fitted with flat blades, or armless wipers, as standard features. These wipers clean more effectively, particularly at higher speeds, owing to the more even pressure they exert on the windscreen. This new system can be retrofitted to many older cars. Flat blades are more expensive than conventional wipers; however, since they also have a longer service life – up to two years according to TÜV SÜD's experience – drivers end up recouping part of the extra cost.
Arms: If visibility is not restored by new wiper blades and a clean windscreen inside and out, perhaps the wiper arms themselves are at fault. If a new high-quality wiper blade rattles, it may not be in contact with the windscreen at the right angle. Repair workshops can measure the 'offset angle' using special gauges and correct the setting where necessary.
Rear view: Rear windscreen wipers are often overlooked – after all, they are not constantly within the driver's field of vision. They are often treated carelessly when windscreens are being cleared of ice. The rubber edges of old wiper blades may tear, a problem not immediately noticeable in a rear wiper – until, in the best case, visibility is impaired in the next rain shower. However, there is also a risk that metal parts of the wiper blade may scratch the windscreen.
Light: Drivers of older car models with small headlamp wipers should also check these systems. False economy here may have its revenge; while smear-free cleaning is not absolutely necessary, worn or missing rubber blades will not only fail to clean the headlamps, but may – as with rear windscreens – leave unsightly scratches in the headlamp glass and cause undesirable refractions in the headlight beam.
Newer headlamp cleaning systems use high-pressure sprays. But inspection of these components by drivers is an important task, given the harsh winter weather just around the corner. "Incidentally, when a vehicle is brought in for a roadworthiness inspection all the wiper systems must function correctly - including rear windscreen wipers and headlamp wipers where applicable", warns TÜV SÜD's expert Lang.
Treatment: All drivers can influence the lifespan of their car's windscreen wipers. One of the worst ideas is to use windscreen wipers to remove light coatings of ice from the windscreen. The sharp crystals in the ice destroy the wiper edge – which is only a few hundredths of a millimetre thick – after only a few sweeps. Leaves and conifer needles are not much better; if they end up under the blades, the only solution is to remove them by hand – preferably before setting off.
Anti-freeze: Some drivers still use methylated spirits to prevent the washer water from freezing. "There are several reasons why this method is unsuitable", explains Eberhard Lang. Methylated spirits do not contain cleaning agents and will cause annoying smears across the windscreen, particularly with fan jet systems. These modern jets deliver a broad spray and require strict adherence to specifications for anti-freeze and cleaning agents. Here too, the TÜV SÜD expert advises the use of branded products to be on the safe side, given that they are only slightly more expensive – and less odorous – than methylated spirits.
Dosage: While many drivers believe that "more is better" where anti-freeze is concerned, this is not the case. Using the concentrated solution neat is not only expensive and damaging to the environment, but also ineffective, as the thick brew cleans less efficiently than the correctly diluted mixture. It is therefore worth paying attention to the dosage of anti-freeze. Drivers unwilling to do this can buy ready-diluted anti-freeze to protect their systems at temperatures of up to minus 20 degrees. There is rarely any need for measures designed for lower temperatures in Germany, and anti-freeze for temperatures of up to minus ten degrees is adequate for the interim period leading up to winter. The obvious exceptions to this are freak cold snaps and travel to chilly regions such as mountainous areas or Scandinavia.
Contact: Frank Volk