Another Continental supporter. I am told I also have a heavy foot (which is a relative opinion), but my ContiContactPro non-RF lasts longer than yours. Do you track your cars, SLK/E? or perhaps tire pressures? Or I drive like grandma then. I had thought about switching to ExtremeContact, but since these are working great, I have hesitated to change.

 

I don't track my car but I am very heavy (lead) footed... no grandma driving for me... I am curious how the ContactPro will turn out, especially since they are my first RFTs. Lots of opinions pro/cons for RFTs for sure... I only have 1 yr driving on these so will see. OTOH, the DWS06 have tons of ride experience and I love them, so very biased.

 

Generally speaking tire psi correlates to load capacity, and that may contribute to durability and the reason Mercedes sets the pressure to 40psi. If you change tire size or switch away from run-flats, you may want to be aware of this.

 

Most shops inflate the tires to the pressure listed on the door jamb unless told otherwise. They have to by law, unless the customer opts out on the work order. I always opt out and tell them not to change it. That pressure is known as the max load pressure and is for when the vehicle is loaded up to its gross weight. In the USA due to the Firestone issues in the 90s, the DOT decided to only list max load on the sticker as that is the safest pressure. For normal driving just by yourself, barely anything in the trunk and potentially 1-2 passenger that's what the normal tire pressure listed on the sticker inside of the fuel door is for. There are usually other pressures for when you want to drive higher speeds for extended periods. In some vehicles the pressure needs to be increased for speeds above 100 mph, in AMGs it needs to be increased for speeds above 155 mph.

You are correct, it comes down to load, but more specifically the tire deflection. It's the "bulge" that a tire makes under load or the torque applied to it. As you roll, this constant deformation creates heat. The more load that is put on or the higher the speed the more deformation occurs. Air pressure is used to counter that deformation and make sure the tire doesn't overheat. Every tire has a load rating. It's the number next to the speed rating letter. Every tire also has a max PSI that's found on the sidewall. Usually 50 psi or a little higher. That's the pressure at which the tire can hold its max load as specified in the load rating. By lowering the tire pressure you reduce the max amount of load that the tire can carry in exchange for comfort. So most vehicles use tires with a higher load rating than needed in order to be able to lower the tire pressure down from the max pressure on the sidewall.

Just to be clear. These are always cold pressures.

 

Yup. The OE tires (almost exclusively run flat on MB sedans) are a balance of ride comfort, durability and load requirement; not to mention the elimination of a spare tire for weight, space and cost reasons. Pump your run flats up to 40psi and see what it does to ride comfort.

GVWR (gross vehicle weight rating) is shown on the VIN sticker, usually on the driver's side door jamb. My W213 E350 lists the total gross weight and separately shows the gross front and gross rear (see attached). If you switch to non run flat tires or to different tire sizes, say a lower profile (wider), the new tires may not meet the GVWR at the tire pressures recommended on the fuel door. However, you may be able to meet the specs by increasing tire pressure, which increases load capacity. There are charts that will show the load values at various pressures.

 

I am going to bookmark this answer for future "tire pressure arguments" with others. They are recurrent as night and day. Thank you very much.

 

Heat has a big impact on your tires wearing. Here in Texas, when 6 months a year its over 105F, that is just air temp the roads are very hot and it impacts your tire wear. I've noticed my motorcycle tires wear about 30% faster here in Texas compared to my bike when we lived in MA.

 

My Wagon came with the Goodyear Eagle Run Flat tires and I got rid of them at 10K miles for a set of Michelin Primacy 3 Runflat tires and very happy I did that. The Goodyears had a extremely harsh ride and after have them removed I could see why, the tires are extremely stiff, like a rock. The Michelins ride much better and now the car has 34K miles on it so far thats over 24K miles on the tires and they still look good. I'm amazed you haven't damaged your rims on Long Island with the way the roads are so pothole ridden with those Goodyear Run Flats. If you needed a All season which you probably would being in NY the Continental DWS 06 plus might be your best option, the Primacy 3's are summer only tire but serve me fine in Sunny Florida.

 

I think I'm going to get Michelin Primacy all-season tires when the time comes. I've heard a lot of good things about them. We haven't had any complaints in terms of noise or ride harshness with the Goodyears. We drive very carefully so we've been able to avoid road damage to our tires or rims so far.