Seems to me that wheels (including tires) that are larger than stock are going to stress auto transmissions significantly more than stock wheel = tire combos under heavy acceleration. Has anyone considered this possibility?

 

80% of peoples "upgrades" are the eqivalent to stock size.

A 245/35/20 is within mm's of a 245/45/18 when it comes to circumfrence.

Alot of it is driving habits. I've had my 5AT since 2003 with ZERO issues, tranny or other.

I have also used the sport shift maybe a handful of times, a problem may result from constant use.

 

This may be the case with smaller cars, i.e. 4 cyl with much less power than our Maxima's. Once you start increasing "unsprung weight" it could put extra stress on your tranny. I have a 98 civic with auto tranny and within the last 6 months it has started slipping between 2nd and 3rd. A couple of years ago I upgraded to 17's from the stock 14's and the weight increase was quite significant. Not sure if the rim/tire change has caused it to start slipping or if the fact that the car has 300000 Km's on it, and it's just normal wear and tear over time.....

As KC stated, the upgraded size (205/40/17) is equal in circumference to the stock size (185/65/14) but the weight increase in some cases is much more.

 

Thanks, KC and sensfan for the clarification.

 

there is a plus 2 inches acceptance for cars. now once you get to 22+ then maybe some concern.

 

I think the unsprung wieght issue makes sense in this case bc of the force needed for the extra weight.