Manufacturer counters Autozeitung GT Radial SportActive test results
Giti reports it has completed an independent test with Dekra to evaluate the wet braking performance of its GT Radial SportActive tyre against several leading products as used in the original Autozeitung article. The firm also called for all “manufacturers, key associations and informed publications” to standardise testing in order to avoid grey areas.
The test took place over two days in March 2016 at the accredited Idiada test facility in Spain. The vehicle used was a VW Golf 7 2L TDI 150HP manual, with 100 per cent ABS on. The vehicle ran on 225/45 R17 W/Y tyres.
The GT Radial tyres were supplied by the Giti’s German distributor from stock, while the competitor tyres were purchased on the open market by Dekra, who also rented the vehicle and undertook the tests with their own staff.
The car was set at full load – four passengers and 40kg of luggage – and all tyres were inflated to the vehicle manufacturer’s recommended pressures. The tests were conducted on asphalt in wet braking zone two, with the braking distance measured from 100 – 0kph.
To achieve the average results a minimum of six runs were completed, the first was not taken into account while the remaining were validated to reach an average figure.
Putting the Continental SportContact5 and the Westlake Sa-37 to one side as the best and worst performing, the results clearly show that the five other tested tyres achieved an average wet braking distance of 40.40 – 42.00 metres, which is a small 3.8 per cent differentiation in performance.
During testing it was possible to again look how various, uncontrollable weather elements have an affect on results, managing runs with temperatures as high as 16˚C and as low as 5.9˚C. These alone created wet braking deviations of up to 8 per cent.
Giti points out that the results call into question those reported by Autozeitung. They also contradict the many negative headlines against Far Eastern tyres in general and clearly including GT Radial.
“Furthermore, we will continue to analyze the content and statements of the report which aired on SWR on March 8, 2016 with an interview from a Gesellschaft für Technische Überwachung (GTÜ) expert in which many of the stated facts in relation to tyre testing are simply incorrect”, the official statement explained.
However, apart from the test results themselves, the most striking part of Giti’s statement is its call for industry-wide test standardisation: “We call for all manufacturers, key associations and informed publications to create an improved standardisation of test conditions in order to inform the market with truly accurate results.” It will be interesting to see what, if any, the response will be.
Giti/Dekra SportActive retest results
Manufacturer Pattern WB* RR** Temp (˚C) Average (m) Continental SportContact5 A E 12 36.30 Toyo T1 Sport B F 11 40.40 Hankook K117 ventus evo2 A E 11 40.60 Bridgestone T001 A E 10 41.00 Kumho KU39 Le Sport B C 10 41.80 GT Radial SportActive B C 11 42.00 Westlake SA-37 B C 13 44.20
Source: Giti, Dekra
* Wet braking tyre label rating
** Rolling resistance tyre label rating