I would value your advice concerning replacement tyres for my “Mammoth Merc” GL 420 CDI please. Currently it is fitted with Pirelli Scorpion Zero 275/55 R19 111V M&S (MO) which is the standard Mercedes-Benz fitted and recommended tyre for this car. They are great tyres, with fantastic grip in the wet or dry, and not bad either in light snow and, with the car’s electronic stability controls, give this rather large 4×4 SUV surprisingly car-like driving characteristics. Only problem with them is that as performance rubber, they wear quite quickly. I fitted four new ones about 17,000 miles ago, and a guesstimate is that they will need to be replaced again in about three to four thousand miles now, as they wear down towards the tread wear indicators, and certainly before winter arrives again. I know that high tyre wear is a price for driving such a powerful, heavy SUV, but longer tyre life would be nice. The alignment has been checked and is fine, and all the tyres are wearing evenly. Tyre pressures are regularly checked and maintained to 32psi front/back, as per Mercedes-Benz recommendations, and the brakes are fine and not binding. We don’t drive the car hard, and use it only on the road.

I contacted Mercedes-Benz UK, and they sent me a list of the approved tyres for my car. There are choices from Dunlop, Michelin and Continental, together with the aforementioned Pirellis, for example, but are high performance designs with (presumably) soft tread compounds and consequently fairly short life. Winter tyres are available, incidentally, but Mercedes-Benz also recommends the Dunlop Groundtrek 275/55 R19 111H AT2, which is apparently the only all-terrain tyre in a suitable size/speed/load rating for this car. It has slightly more rolling resistance and lower aquaplaning resistance than the road-biased tyres recommended for the GL. This size of Dunlop Groundtrek isn’t officially available in the UK, but can be easily ordered from German/Dutch websites. As an ‘all terrain’ type tyre, the Dunlop Groundtrek is an inevitable compromise between on and off-road performance, but has the advantage of a non-symmetrical tread pattern with a harder rubber compound which should last much longer than the road biased current Pirellis. What type of tyres would you suggest I replace my Pirellis with when the time comes? I’m almost convinced that the all-terrain would be a more practical choice, especially considering our driving style and that I’m driving a heavy 4×4 sports utility vehicle, and not a BMW M3.
Danny Gillis

You’ve obviously spent a decent bit of time looking into this Danny and I have a strong feeling that you are probably better informed than me. But I do feel that going for something rather obscure, like the Groundtrek, with its limited availability, leaves you a bit exposed if they don’t work out too good in practice, or if you were to need another one in a hurry. It seems to me that you’re not really into off-roading and for that reason I would stick with conventional tyres, of which, as you say, there’s not a huge choice. I personally would go for the Michelin Latitude Sport, whose Economy/Wet Grip/Noise ratings are C/B/72dB against E/C/72dB for the Pirelli Scorpions. Michelin tyres nearly always seem to wear better than the competitors’ and I’ve read of people getting towards 40,000 miles on the Michelins. I found what’s probably a best home delivery price at Camskill, for £189 a corner, plus just £2.99 per tyre delivery, which seems a keen price. Keep in touch. Best regards,
Doc Diesel

Then Danny came back:

Thank you Doc. Your advice is very helpful, as I haven’t used Michelin tyres for many years now, and hadn’t really considered them as being superior to the Pirellis. I’ll give the Michelins a try when my current tyres reach the wear limits. That’s certainly a very good price from Camskill, which I will follow up. I’ll update you in due course as to how the Michelins wear – hopefully you won’t be hearing from me for a while!
Regards,
Danny