Re: 09 Mariner Slip Indicator
If the tires are wearing unevenly, I'd suspect a front end component is wearing out. A good alignment shop will let you know this. Driving the vehicle over rough roads every day can lead to misaligned front tires and leaving the front end components without any damage or excessive play. It won't hurt to get a proper inspection done. When you get new tires, another alignment might be warranted. If the tires are at 4/32nds at their lowest spot or even less, I would have replaced them then, and had an alignment done with new tires.
Nonetheless, newer vehicles are so electronically controlled that a slight variance in grip between the front tires, to the rear tires, can cause some traction systems to 'panic'. Which may explain why the light came on the dash. I have reason to believe that the alignment was done correctly, as the vehicle weight is now biased to riding on the area of tire with the most tread. As the tires were wearing on the inside, the alignment would have made the tires more biased to where the tread is thicker; on the outer edge, allowing for slightly less road contact on the inner edge. This can also affect braking and even trigger ABS when it's not really required.
As an example, the Audi Quattro AWD system is so advanced that if you wear out 50% of the tire tread, and lose a tire to a nail. The dealer will tell you that it's in your best interest to buy 4 new tires. This is so the electronics can better balance out the power to either axle, which effectively aids traction, braking and overall performance of the AWD system. If the vehicle is under warranty, the dealer might have to install 4 new tires in order to maintain the power train warranty. If you choose to install one new tire only, then your warranty is voided and you'll knowingly have an expensive repair bill after the winter. If you lease, the onus would be on you to purchase 4 new tires; look at the lease fine print before you sign! Acura has a similar policy for vehicles utilizing their SH-AWD. Most vehicles do run low profile tires and have a life span of maybe 30K miles. Most owners overlook the long term, as well as short term costs of vehicle ownership. Ford isn't quite as advanced, so you can effectively run slightly different tire diameters and the system won't fault you for it, but not having a set of tires with 100% of the contact surface actually on the ground, can cause errors.
'11 Ram Quad Cab 4x4 SXT 5.7L HEMI (stock); 48,500m
'06 Pontiac G6 GT 3.5L 220hp; 64,000m
'12 Chrysler 200 Limited 3.6L 283hp; 28,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!
Last edited by 360ci; 03-10-12 at 01:43 PM.
Reason: add on