Autocar Tyre Test 2007 - sponsored by Blackcircles.com
In 2007 the annual tyre test run by Autocar magazine was sponsored by Blackcircles.com. The test aims to assure its authenticity and validity by making sure that industry standard methods of testing are combined with statistical analysis.
The Autocar tyre test compares tyres on two different vehicles, a standard family saloon – in this case a Ford Mondeo 2.0 TDCi – and a more powerful, high performance vehicle – a Mercedes C350. A key reason for doing this dual test was to analyse how the performance of specific tyres varies according to size and when fitted to different cars. In particular, Autocar were interested in looking at the differences in performance between tyres fitted to rear-wheel drive performance cars like the C350 and the same tyres fitted to high-spec family cars like the Mondeo 2.0 TDCi.
For the test Bridgestone, Continental, Goodyear, Michelin and Pirelli were asked to supply tyres. The Mondeo was fitted with size 235/45 R 17 and the C350 with 225/45 R 17. Bridgestone specified the Potenza RE050A for both vehicles, Continental the ContiSportContact 3, Goodyear the Eagle F1 Asymmetric and Michelin the Pilot Sport. The only manufacturer to choose different tyres for each vehicle was Pirelli, who went for the P-Zero Rosso on the Mondeo and P-Zero Nero on the C350. Autocar also ran the test on a Dunlop Direzza track tyre in order to measure what levels of grip could be generated with a specialist tyre.
In reporting their results, Autocar differentiated between the front and rear-wheel drive vehicles and wet and dry performance.
Front-Wheel Drive - Dry
In analysing the differences in performance of the five tyres, Autocar were keen to point out how the performance balance of the vehicle could be altered to suit personal taste simply by changing the tyres fitted.
This first test carried out was a lap-speed test carried out over three laps, an area in which the Michelin Sport was the clear winner. Indeed, not only was the Michelin the quickest tyre, it also achieved the narrowest interval between the three recorded times. Autocar put this performance down to a number of factors, in particular excellent grip and apex speed, strong traction on the hairpin and first-rate composure on the faster direction changes. The tyres, however, were considered to be relatively slow in heating up and displayed some understeer until they were properly warm.
The Bridgestone Potenza RE050A was considered to be slightly slower than the Michelin but allowed and encouraged more driver input than the Pilot Sport. In particular the amount of driver control that could be exercised from the rear axle was praised, allowing a particularly enjoyable drive whilst retaining high levels of security and trustworthiness.
The Goodyear Eagle F1 recorded a slightly faster time than the Bridgestones and gave the best steering feel and sharpest turn-in of all the tyres. It did, however, perform slightly worse in terms of grip and apex speed.
The Continental’s key area of strength was considered to be in providing a safe, controllable and predictable drive, particularly as the tyre approached its limits. It did, however, provide the slowest lap time, slowest apex speeds and the worst lateral grip.
The Pirelli P-Zero Rosso was considered to be the worst of the tyres tested primarily because of the tyre’s unpredictability at its limits, particularly on the rear. The tyre performed relatively well on cornering speed but the lack of grip control, the fact that the tyre produced the most movement under braking and sub-standard steering feel resulted in the slowest lap times.
Front-Wheel Drive - Wet
In the wet the difference between the fastest and slowest lap times was much greater. The Goodyear was the quickest tyre and was considered to be the best performer in the wet by some distance. Indeed, Autocar were keen to point out that the Mondeo fitted with Goodyears was capable of matching the lap time of the C350 when fitted with the worst performing tyres (the Pirelli P-Zero Neros). Autocar praised the consistency of the Goodyears’ lap times but also the stability of the vehicle when fitted with the Goodyears as well as the cornering grip and sharp turn-in.
The Michelin was rated the second best tyre by Autocar, also achieving good consistency in lap times and good grip, just falling short of the Goodyear on high-speed corners.
The main strength of the Continentals was, once again, their safety and predictability, without being exceptional in any particular area.
The Bridgestones and the Pirellis fell short of the performance of the other three tyres in the wet with the Bridgestones offering the slowest lap time.
Rear Wheel Drive - Dry
In the dry testing for the C350, Autocar once again emphasised the contrast between the secure and predictable handling of the ContiSportContact 3 and the erratic behaviour of the Pirelli P Zero Nero. The Continentals were considered to be well-balanced and easy to drive despite the fact that the tyres were ultimately outperformed by some of its competitors in terms of pure grip. Despite this, and a tendency to understeer on long corners, the predictability of the handling allowed the Continentals to achieve the third best lap time.
The unpredictability of the Pirellis, on the other hand, was considered to be worse on the rear-wheel drive C350 than on the front-wheel drive Mondeo. Autocar crticised the tyre’s steep fall-off in grip and an inability to stabilise quickly enough after a directional change.
The Bridgestones were judged to be good in terms of balance and predictability but were not able to produce as good a comparative lap time on the rear-wheel drive car as they did on the Mondeo.
Again, the Goodyears and Michelins battled it out for top spot. The Michelins were considered to be better in terms of cornering and braking grip as well as in steering feel. The Goodyears, however, were judged to provide a better overall balance, the tyre’s performance through the three s-bends being particularly praised. Despite the lack of grip, the tyre’s balance and dependability allowed it to achieve the best lap time.
Rear-Wheel Drive Wet
The Michelin was used as the control tyre for the wet rear-wheel drive test and , although it performed well, it was ultimately beaten by the Goodyear Eagle F1, which triumphed in terms of turn-in performance and cornering grip, outstripping both the Bridgestones and particularly the Pirellis in this regard.
The Goodyear was also best in braking, allowing significantly later braking than any other tyre on the hairpin, despite having achieved faster speeds due to superior traction. The Pirelli was the least predictable of the tyres, providing the widest lap time grouping and because of this ultimately produce the worst lap times, even falling below the Bridgestones, which were subjectively rated the least impressive of the tyres.
The Goodyears produced easily the best lap times, being 1.8 seconds quicker than any other tyre.
The performance of the Continentals was considered to be medium to good, which was considered to be a surprise. They performed better than the Michelins in lap times but slower than the Bridgestones. However, Autocar judged the car to be a good tyre to drive on the test circuit, offering good predictable grip and consistent response during turn-in.
Overall, though, the wet weather test was won by Goodyear by a considerable margin.
The Goodyear Eagle F1 Asymmetric was the winner of both the tyre tests carried out. However, the Michelin came a close second in the Mondeo size whilst the Bridgestone ran the Goodyear close in the C350 size. Pirelli came bottom in both tests although the P Zero Rosso on the Mondeo performed worse than the P Zero Nero on the C350. The Continental provided the reliable middle ground on both tests, whilst the Bridgestone proved to be less consistent performer, only just beating the Pirelli in the Mondeo size and showing some wide variations in performance across the individual disciplines.
Overall, Autocar considered that the correlation in performance between the tyres tested was good enough to predict that the differences noted in the performance between the various tyres are likely to be carried over onto other vehicles and tyre sizes.
In terms of recommendations, Autocar suggest that the Goodyear and Michelin are the best choices as all-round performers, closely followed by Continental, but add that the Michelin would be the best bet for any driver wishing to focus on dry weather performance.