Talk'n Tires

Wednesday, September 30, 2009 by Porter Pryde

The new Michelin Pilot Sport All Season Plus has been available for just about a year now and that is just about how long I have had my set on my Jetta.  By now, they have been subjected to a full cycle of Midwest weather and driving conditions and have proven themselves versatile and capable. 

My initial concern was how would these All Season tires behave in Winter weather.  We have deep snow and icy roads around here that would keep sensible people home.  After the usual first snow storm slip and slide, the tires, or my driving, settled down to a predictable level of steering and brake input providing a confident ride.  Traction on wet roads was very impressive with lots of grip in light and heavy rain.

For maximum traction in snow, nothing beats a dedicated Winter tire and if that is what you need, you should check out our Winter tire and wheel packages.  Otherwise, for a combination of very good ride comfort, predictable handling and braking in a wide range of weather, the Pilot Sport All Season Plus is a tire to take seriously.




 


Comments on Talk'n Tires

Friday, December 20, 2013 by Brian:
I installed a used tire with the tread about 1/32 off from other 3 tires.. is this bad for the vehicle?
Friday, December 20, 2013 by porter:
The ability of four-wheel drive and all-wheel drive vehicles to divide the engine's horsepower between its four tires is especially useful on loose or slippery surfaces such as sand and dirt, as well as on wet, icy or snow-covered roads. However it's important to remember that in order to transfer this extra power, the four-wheel drive and all-wheel drive vehicle's driveline mechanically connects the tires so they work in unison.
Four-wheel drive and all-wheel drive vehicles are equipped with additional differentials and/or viscous couplings that are designed to allow momentary differences in wheel speeds when the vehicle turns a corner or temporarily spins a tire. However, if the differentials or viscous couplings are forced to operate 100% of the time because of mismatched tires, they will experience excessive heat and unwarranted wear until they fail.
This necessitates that four-wheel drive and all-wheel drive vehicles use tires that are very closely matched. This is because different diameter tires roll a different number of times each mile as a result of the variations in their circumferences. Tire diameter variations can be caused by accidentally using different sized tires, tires with different tread designs, tires made by different manufacturers, different inflation pressures or even tires worn to different tread depths.
As an example of different tire diameters resulting from tires worn to different tread depths, we'll compare two 225/45R17-sized tires, a new tire with its original tread depth of 10/32-inch and a second tire worn to 8/32-inch of remaining tread depth. The new 225/45R17-sized tire has a calculated diameter of 24.97", a circumference of 78.44" and will roll 835 times each mile. The same tire worn to 8/32-inch of remaining tread depth is calculated to be 1/8" shorter with a diameter of 24.84", have a circumference of 78.04" and will roll 839 times per mile. While the difference of 1/8" in overall diameter doesn't seem excessive, the resulting 4 revolutions per mile difference can place a continuous strain on the tires and vehicle's driveline. Obviously, the greater the difference in the tires' circumferences, the greater the resulting strain.
This makes maintaining the vehicle manufacturer's recommended tire inflation pressures and using "matched" tires on all wheel positions necessary procedures to reduce strain on the vehicle's driveline. Using "matched" tires means all four tires are the same brand, design and tread depth. Mixing tire brands, tread designs and tread depths may cause components in the vehicle's driveline to fail.
Mismatched tires or using improper inflation pressures for all-wheel drive and four-wheel drive vehicles can also result in immediate drivability problems. Some Control Trac equipped vehicles in 4Auto mode may exhibit a shutter on acceleration and/or a noise from the front driveline and transfer case while driving. Some all-wheel drive and four-wheel drive vehicles may exhibit axle windup or binding while driving. Some four-wheel drive vehicles (manual or electronic shift) with a two-wheel drive mode may refuse to shift "on the fly" into 4x4 Auto or 4x4 High at highway speeds.

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