2mbusa

Replaced the factory equiped General tires on our 2001 ML320 after about 45K miles and what a difference. We put on Toyo Open Country tires and the handling is far better -- it almost feels like the new 164ML, even after about 3k miles of driving. I think the MB factory missed the boat when they supplied the ML with Generals. We also had the new Toyo's siped at the tire store as they said this would greatly improve any tires traction potential. I also took my SL in and had its tires siped and found it much harder to get the rears to break lose from over accellerating on a corner -- sipping seem like a good move. I had never heard of sipping before, has anyone else had experience with sipped tires?

sosh

Siping was used years ago for truck tires particularly those with a heavy cross bar tread design. It does increase traction but also cuts the tread life in some cases to almost half, increases noise a lot and the small sipe grooves pick up pebbles and they can cause damage to the tire casing and even to the car when they are thrown out at high speeds. With today's modern tires the small difference in traction is certainly not worth it. Some tire manufacturers will void the warranty for siped tires. In our world today its just another "profit center" for tire dealers. When I was young my family owned one of the largest independent truck tire distributors/retreaders in the US.

2mbusa

The tire dealer that did the sipping on both my ML320 and our SL500 assures me that it does not void the tire warranty and that along with greatly increasing the traction it makes the tires run cooler and, therefore, ware longer. Les Schwab is the largest and oldest dealer in the Pacific Northwest and they should know what they are doing by now. They also provide their free additional unlimited warranty on the tires which includes miles. They were able to show me some tires in a brand and size that I did not want that come from the factory already sipped.

I have not noticed small stones in the sipping cuts while there have been some in the factory treads. What I have noticed is much greater traction from the Continentals that came on the SL. Could be the technology for sipping has changed -- hope so!

Ronin007

sosh - I think you are confusing siping with grooving. Siping is the minute slits put in the tread to provide additional gripping properties to a tire. These are so small that you would be lucky to pickup a small sand pebble. Look at any modern snow tire especially the Blizzaks and you will see thousand of sipes across the tread. It is actually the siping in conjunction with the new tire compounds that make a Blizzak tire perform so well on ice and snow without the need for studs. 2mbusa is correct in that they will run cooler also and can extend the life of the tire.

Grooving is where you are removing or creating additional tread blocks or creating rain channels in a tire. This as you stated can void warranties, decrease tire life, and cause a tire to chunk at speed if done improperly. I have used grooved tires both in road racing and in off road applications. Personally I have never had a problem with grooved tires, but mine were always done by the tire manufacturer at the event. A lot of rock crawlers now days are using not only specially grooved tires, but siped tires as well. The sipes add the extra grip that they need some times to make a gate especially when it is raining.

MTL_HK

Congrats on your Toyo tires purchase!!

But mind u one thing, the Toyo tires tread life are so limited when equipped on ML truck. Coz Toyo tires are mostly suitable for lighter vehicles.

Anyhow, good buy though.

Performance counts.