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Friday, October 31, 2014

Doug's Domain

Doug Vetter, ATP/CFI

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Tuesday, December 2, 2003

(Image: Hunter Tire Mounting Equipment)Wow. What a difference a set of tires can make. I just got home from the dealer with the new Michelin Pilot Sport A/S tires on the car and I cannot believe how much differently the car feels and drives with the new tires.

Some notable improvements:

I took the car up to 80 on a back road and, again, all I can say is WOW. I will never put another Dunlop tire on this car...to do so would be an affront to the quality of the car and the driving experience it can deliver...with the right tires. My mechanic was right all along.

And, for you skeptics, I think I can get away with saying that the car drives better than when I drove it off the lot by considering the car came from the factory with Dunlop tires. If you'll look back at first maintenance entries in 1998, you'll note I had problems with steering wheel vibration. What I didn't know then was that this was NOT due to some steering pump problem...it was due to flat-spotted and out-of-round tires that eventually "heat cycled" into shape. Sort of.

Of course, my mechanic was able to get more objective measurements of the new tires by using about $25K worth of tire mounting and balancing equipment (shown above -- mounting equipment on the left, road force/balancer on the right). Considering the cost of the equipment and the positive results, I'd say the $40/tire I spent for mounting/balancing/disposal is a bargain.

My mechanic told me that two of the tires produced about 6 lbs of road force, while the other two were just under 10. This is higher than his original estimate, but well below the maximum BMW (18) or Michelin (25) specifies. Naturally, the two 10's were mounted on the rear, but I'm here to tell you that you CANNOT feel 10 lbs of road force (on the rear, anyway).

(Image: Hunter Tire Balancing Equipment)Some recommendations that I've developed as a consequence of my experiences with tires on this car:

While the wheels were off, I also had the front pads and rotors changed, the brake fluid flushed (about 6 months ahead of schedule, but while in Rome...), and a mid-cycle synthetic oil change performed. Next major maintenance will be an Inspection I, in about 6K miles, or sometime in the February/March timeframe.

Total damage: P&L (excluding tires): $800. Mileage: 87609.