I've only got 10K mi so I don't need new tires yet, but wanted to ask this question...

Suppose I damage a single tire and need to replace it - What is required when replacing tires on the AWD models? Do I have to replace tires in sets of 2 (or all 4 at same time) or can I replace a single tire if others have some wear?

What about replacement through normal wear and tear - can you replace in sets of 2?

Note that the G37x tires are all the same size.

I heard a horror story from an AWD Suburu owner who damaged a single tire and was advised to replace all 4 even though other tires had good amount of tread life - not sure if he was handed a load of BS by his salesman or not...

This is my first AWD car and typically I've replaced tires single tires or tires in sets of 2 on previous front-wheel drive cars when damage occurs to a single tire and all tires have a good amount of wear on them (ie are not new).

 

The G37x is normally rear wheel drive and only switches power to the front wheels when needed and in the percentage of power that is required. I would treat it as a rear wheel drive vehicle when considering partial tire replacement.

 

They really ripped that Suburu owner. If 1 tire is damaged just replace 1 tire. The car will drive fine, no need to replace 2 or 4.

 

First let me say regarding the OP that you should be fine replacing just one tire. The small difference in diameter should not affect the AWD system.

In reply to this post, whether the system is biased to RWD has nothing to do with this question. The issue is that most AWD systems transfer torque based on differencial wheelspin, and if you put a smaller tire (i.e. compact spare) the system will detect that as a significant wheel speed differential and constantly transfer torque away from that wheel (or between front and rear wheels) which would not be good. With the Subaru the owner's manual explictly instructs you to pull a fuse to disable the AWD system when a compact spare is on the car.

Our spare tires are only about 1/2 inch diameter off from the standard tire (145/80D17 vs. 225/55R17) and there's no warning in the owner's manual regarding AWD issues when using the spare so you should be 100% fine with only one new tire.

 

Matching Tires on Four-Wheel Drive and All-Wheel Drive Vehicles

 

Thanks to all for your responses.

The tirerack info was very helpful too, so special thanks to Neal. I've purchased from tirerack in the past and have been very happy with their service and product.

Another question - How often are G37x owners rotating their tires?

I brought my car in for an oil change at 7500mi and the dealer told me I didn't need a tire rotation even though the maintenance schedule recommended it at that time. So should I insist on tire rotation at 11,250mi or wait?

 

Recommended tire rotation (Infiniti schedule) is every 7500 miles. The dealer should have done it just based on their own recommended maintenance. In fact you'll find that most places recommend more frequent rotation (Tire rack recommends every 3000-5000 miles). Waiting longer could cause poor wear patterns that could be caught earlier.

 

Correct. The chances for irregular tire wear is greatest early in a tire's life. Best to rotate every 3K for the first 10K on new tires. After than Infiniti schedule is ok.