scoobdude
01-26-2006, 01:11 PM
Off the BFG forum:
December 30, 2004 10:23PM ???Center wear on rear KDWS's by Warren We use KDWS 245/55-18 on all are rear tires (03&04 Marauders)and they all seem to wear in the middle first on the rears. In fact the rears wear first before fronts. We run 30 or 35lbs. as per 03 and 04 Ford door stickers. All are well balanced and aligned right. This occurs with normal driving not just those we race or have S/C's. Any Thoughts. Warren
**Center wear on rear KDWS's by MENINBLK February 24, 2005 2:10PM Thank you for posting your explanation. We (Marauder Owners) have been having a debate over this, and our experiences are that if we run this tire with a slightly higher pressure than what Ford recommends, we get more even tire wear and a longer lasting tire as well. The majority of us are using 38psi in the front, and 40psi in the rear, and we have seen dramtic results. Thanks again for your explanation. Pete...
THIS NEXT POST IS VERY INTERSTING!!!!! :devil:
*RE: RE: ???Center wear on rear KDWS's by TireNerd2 February 23, 2005 9:28PM Nope. The KDWS does not have a softer compound in the middle of the tread. The KDWS uses a single tread compound accross the entire face of the tread. Center rib tread wear can be caused by many things. However, take it from me as a Tire Designer (6 years) and Ex-Test Driver for BFG (6 years), rear wheel drive, high horsepower, and high torque applications that exhibit accelerated center rib wear usually benefit from INCREASING cold inflation pressures. Now I know absolutely everyone in the public domain will tell you accelerated center rib wear is caused by over inflation, but believe me it's also caused by under inflation on the 'driven axle'. So in a sense both situations lead to center rib wear depending on whether the axle is being driven or not i.e. whether the tire experiences an engine driving torque or not. Adding some air to the rear axle of the Marauder in this example will stabilize the contact patch and help it maintain its shape better by keeping more rubber on the road under a driving torque. Essentially, if a driven axle tire is under inflated when it experiences a high driving torque, the leading edge of the contact patch is forced into the road and the trailing edge of the contact pathch is 'pealed' up (you can watch dragster tires do this when they stage at the line). When this happens the unit contact pressures increase at the leading edge of the contact patch, which increases contact stresses and accelerates wear. The centerline of the contact pacth just happens to be the location of highest contact pressures and so exhibits the highest wear rate. I know this may sound odd - and I know maybe counter to what you've heard BUT adding air reduces center rib wear in higher horsepower applications by stabilizing the contact patch shape. Keep in mind O.E. inflation pressures are a comprise by the manufacturer for ride and handling and not optimized for tire wear life. So add at least 5 to 7 psi cold to the rear axle tires and the KDWS wear life should increase.
Yes the marauder does have a wear issue. It's not because of the car, but the tires themselves. The new GTO has the same problem but they run 245/45/17 KDWS. You see the center of the KDWS is a softer compound than the rest of the tire. This helps when it comes to traction but yet it does wear quicker. Also you might want to check your front tires because they are probably worn on the inside edge. Another issue that the marauder has. This is actually an alignment issue that is fords fault. The specs that they use are the same as a grand marquis even though the suspension is slightly and the front end is heavier. Next time you have the car aligned tell the tech to set the total toe measurement at 0.00. This will take stress off of the inside of the and put more towards the middle and give you better wear. As for the rear you could try lowering the air pressure but the sidewalls are so stiff on the KDWS that I don't think it will help.
December 30, 2004 10:23PM ???Center wear on rear KDWS's by Warren We use KDWS 245/55-18 on all are rear tires (03&04 Marauders)and they all seem to wear in the middle first on the rears. In fact the rears wear first before fronts. We run 30 or 35lbs. as per 03 and 04 Ford door stickers. All are well balanced and aligned right. This occurs with normal driving not just those we race or have S/C's. Any Thoughts. Warren
**Center wear on rear KDWS's by MENINBLK February 24, 2005 2:10PM Thank you for posting your explanation. We (Marauder Owners) have been having a debate over this, and our experiences are that if we run this tire with a slightly higher pressure than what Ford recommends, we get more even tire wear and a longer lasting tire as well. The majority of us are using 38psi in the front, and 40psi in the rear, and we have seen dramtic results. Thanks again for your explanation. Pete...
THIS NEXT POST IS VERY INTERSTING!!!!! :devil:
*RE: RE: ???Center wear on rear KDWS's by TireNerd2 February 23, 2005 9:28PM Nope. The KDWS does not have a softer compound in the middle of the tread. The KDWS uses a single tread compound accross the entire face of the tread. Center rib tread wear can be caused by many things. However, take it from me as a Tire Designer (6 years) and Ex-Test Driver for BFG (6 years), rear wheel drive, high horsepower, and high torque applications that exhibit accelerated center rib wear usually benefit from INCREASING cold inflation pressures. Now I know absolutely everyone in the public domain will tell you accelerated center rib wear is caused by over inflation, but believe me it's also caused by under inflation on the 'driven axle'. So in a sense both situations lead to center rib wear depending on whether the axle is being driven or not i.e. whether the tire experiences an engine driving torque or not. Adding some air to the rear axle of the Marauder in this example will stabilize the contact patch and help it maintain its shape better by keeping more rubber on the road under a driving torque. Essentially, if a driven axle tire is under inflated when it experiences a high driving torque, the leading edge of the contact patch is forced into the road and the trailing edge of the contact pathch is 'pealed' up (you can watch dragster tires do this when they stage at the line). When this happens the unit contact pressures increase at the leading edge of the contact patch, which increases contact stresses and accelerates wear. The centerline of the contact pacth just happens to be the location of highest contact pressures and so exhibits the highest wear rate. I know this may sound odd - and I know maybe counter to what you've heard BUT adding air reduces center rib wear in higher horsepower applications by stabilizing the contact patch shape. Keep in mind O.E. inflation pressures are a comprise by the manufacturer for ride and handling and not optimized for tire wear life. So add at least 5 to 7 psi cold to the rear axle tires and the KDWS wear life should increase.
Yes the marauder does have a wear issue. It's not because of the car, but the tires themselves. The new GTO has the same problem but they run 245/45/17 KDWS. You see the center of the KDWS is a softer compound than the rest of the tire. This helps when it comes to traction but yet it does wear quicker. Also you might want to check your front tires because they are probably worn on the inside edge. Another issue that the marauder has. This is actually an alignment issue that is fords fault. The specs that they use are the same as a grand marquis even though the suspension is slightly and the front end is heavier. Next time you have the car aligned tell the tech to set the total toe measurement at 0.00. This will take stress off of the inside of the and put more towards the middle and give you better wear. As for the rear you could try lowering the air pressure but the sidewalls are so stiff on the KDWS that I don't think it will help.