General Tire launches Grabber GT European SUV tyre
The Continental Tire Group’s General Tire brand has launched the successor to its Grabber UHP, with a new SUV tyre in its wide range most equipped to offer on-road performance, at an event in Gran Canaria for around 100 dealers representing 25 European countries. The largest single group amongst these guests was from the brand’s UK distributor, Micheldever Tyre Services and its customers. Visiting the last SEMA show in Las Vegas – “the home of 4×4” according to MTS wholesale director, Alan Baldwin – the wholesaler reported that General has a 4×4 market share into double figures, proving its significance in Europe, despite lacking the original equipment fitments that have come with nearly 100 years of American activity. The availability of General tyres suitable for Land Rover models, which dominate the UK 4×4 market, and the specific market focus of tyres like the Grabber AT have given the brand some notable success in the UK according to MTS marketing manager Amelia Lion – the newly launched Grabber GT taps into a different sort of European market specificity, namely the long-term tendency towards greater on-road performance.
The island of Gran Canaria proved a particularly suitable location to test the new tyre, considering the segment of the European market into which this tyre is intended to fit. To travel between the sand dunes of the beautiful beachside Circuito Maspalomas and the volcanic island’s mountainous interior, traversing, climbing and descending many steep inclines, drivers encounter pristine tarmac roads. While General has a strong heritage and reputation for off-road performance, long-term European market trends have given the tyre-maker the impetus to design the Grabber GT – or “Gran Turismo” – for “100 per cent road use”.
Various factors, including the European-isation of the tyre’s development and the launch of the EU tyre label, coalesced to lead General down this path. Amongst the wide-ranging stylistic changes from the Grabber UHP, the R&D project manager for the Grabber GT, Stephan Herbst explained that “competitiveness in labelling” was one of the most important developmental considerations during the tyre’s gestation period. In the works since September 2010, when the requirements for the Grabber GT project were defined, the tyre’s tread pattern underwent three evolutionary steps, which took it in a radically altered direction to the Grabber UHP. Herbst told Tyres & Accessories: “the tyre is a complete change from the Grabber UHP, which had an open, directional tread… [Its asymmetrical tread] and closed shoulders are designed to improve road comfort and its wear profile.” During product demonstrations, Tyres & Accessories was given the opportunity to see what this means practically.
Grabber GT’s characteristics
During the launch of the Grabber GT, dealers were given the opportunity to test the tyre’s road-going characteristics using three vehicles representing a good cross-section of the market at which the 100 per cent road tyre is aimed. On track, the sedately paced Volkswagen Tiguan and its much sportier cousin the Audi Q3 gave a good indication of the tyre’s comfortable ride and more extreme performance characteristics respectively. On Gran Canaria’s roads, the Land Rover Freelander 2 showed off the tyre’s real-world driving characteristics in dry, summery conditions, probably the most striking aspects of which were its quietness and comfort properties.
This subjective assessment tallies with the defined requirements Herbst and General Tire EMEA 4×4 product manager, Andre Pager elucidated from pre-development research. While the Grabber UHP is a top performer in USA-based Tire Rack’s Street/Sport Truck Summer section, achieving slightly improved performance on General’s identified rivals, the Avon Tech ST and Kumho’s Ecsta STX in the website’s Combined Road and Track Ratings, Herbst identified the “number one customer survey complaint” as noise, with drivers also requesting greater high speed stability. In a comparison with the main competitors during the pre-development stage – including tyres from Dunlop, Bridgestone and Yokohama in addition to Kumho and Avon; a brand comparison that UK dealers tell T&A is apt from their point of view – General identified the need to “improve objective noise, rolling resistance, even wear and dry handling characteristics” over the UHP, a conclusion additionally informed by the tyre label. Therefore General developed the Grabber GT focusing on high levels of safety on dry and wet roads, precise handling and further improved fuel efficiency and comfort.
In reaching the final launch pattern, the tread was changed significantly three times. The first proposal was still directional, but the shoulders were closed as a first step towards reducing the tyre’s road noise. Herbst explains that “the results were that the tyre over-achieved in noise and handling” at too great an expense to its resistance to aquaplaning. In response to this, the second evolution increased the void volume and increased the pitch sequence in the centre of the pattern, while adding sipes. This had the effect of improving aquaplaning performance, but reduced mileage and increased noise again, mainly as a result of too great a void.
At this stage, the tyre became a European specialist product, as the American side of the development team was redeployed. Strategically, this swung the tyre towards becoming a 100 per cent road-going tyre; driving habits in Europe allow the tyre to prioritise completely rather than retaining some off-road capabilities required in the North American market. At this point, the largest pattern evolution took place, with General changing the pattern from directional to asymmetrical. Essentially retaining the inside half of the directional tread, a straight rib was added, meaning the outer and central sections were “optimised for handling, mileage and noise”, while the inside section is “optimised for aquaplaning and noise”. Overall, the tyre’s range achieves average tyre label grades of E-C-73dB. This noise rating seems on the high side to General, and is a reflection of the external drive-by noise recorded for labelling, rather than the more important subjective noise, or the noise perceived by the driver, in which characteristic General says the Grabber GT “over-achieves”.
This lengthy development process gives a good idea of the challenges involved in developing a tyre for the SUV/Crossover segment, in which good road contact is of particular importance, since these vehicles can be as powerful as a sports car, weighing twice as much and having a higher centre of gravity, which makes them inherently more prone to traction loss.
The Grabber GT’s asymmetric tread design has large shoulder blocks and 3D sipes for a sturdy tread block structure. The stiff outer tread areas increase precision, while the large number of grip edges in the centre of the tread shortens stopping distances. The tyre’s larger number of tread blocks and grip edges helps to increase the predictability and safety of dry and wet braking performance. Harmonic tread block placing and closed shoulder blocks enhance comfort, while the sturdy block pattern promotes even wear, which gives the tyres a high mileage capability. Finally its closed shoulders create a barrier against the noise generated in the centre of the tyre, reducing noise. Herbst explains that the tyre’s improved subjective noise performance is also “tested across all speeds” and throughout the life of the tyre: “after 25,000km the tyre has much better subjective noise ratings than the UHP.”
General explains that these features have led to overall improvements over the tyre’s predecessor, with a seven per cent reduction in rolling resistance, an eight per cent reduction in noise emissions and a three per cent increase in mileage capability.
Another clever feature included by General on the Grabber GT is visual wear indicators, helping to promote tyre safety checks. Both wheel alignment and tread depth are tackled: the Visual Alignment Indicator (VAI) is a set of small sipes positioned on either side of the tyre at defined points. Drivers should check these sipes after 1,000km, since uneven wear will be indicated by the sipes on one side of the tyre disappearing. Similarly, an inscription in the central rib of the tyre initially reads “Replacement Tire Monitor”, with letters fading to read “Replace Tire” when the tread depth reaches 3mm.
A wide range of SUV fitments
When the project to replace the Grabber UHP was begun, General Tire planned to provide sizes between 15 and 24 inches with speed ratings S, T, H, V and W covered. This was in 2009, and with the benefit of three and a half years of market development, the launch speed profile has shifted up to the range T-Y. It is not that the tyre has changed its focus, but rather that the market for mid-sized to heavy-duty SUVs has evolved upwards. At launch 42 different sizes are available, with 17 of them new.
In total the Grabber GT has fitments for 15 of the most popular 2011 SUV registrations, including such models as the Audi Q3, Honda CR-V, Range Rover Evoque and Porsche Cayenne. In terms of the speed profile, the Grabber GT has fitments for the top 13 H segment sizes – and 16 of the top 20 – the top 15 V segment sizes, and at the top end 11 of the top 20 W segment sizes. In addition to the most popular sizes in the on-road SUV segment, such as 215/65R16 H, 235/65R17 V and 255/50R19 W, the Grabber GT also offers less familiar sizes, indicating General’s ambition for the tyre.
General says this portfolio represents a step forwards into on-road fitments for a brand noted particularly for its high-quality off-road tyres. Being an asymmetric tyre, the Grabber GT is also designed for visual appeal, which extends to the redesigned sidewall. While the tread signifies road-going sturdiness and superior grip, the sidewall includes the dynamic brand logo, an indication of the the tyre’s VAI and wear indicator, the General Tire web URL, as well as mandatory technical information. Overall, the new tyre projects new “ambitions for the brand,” according to Pager.
Available in 42 sizes in spring, the General Tire GT “sits nicely in the mid-range alongside such brands as Avon and Kumho,” according to the brand’s UK dealers, at the same price point as the Grabber UHP.