Hey guys I recently got a good deal on some wheels and tires and the tires are 245 45 20. I know most people use a 35 sidewall on the tires but wondering if anyone personally has used the 45 sidewall on a 20" wheel and if you had any problems with the all wheel drive system? Thanks in advance!

 

With AWD going w/ the same size tire all around is best but those 45 series are almost 2" taller and a whopping 7% different vs. oem diameters.

There are those that switch to smaller diameter tires over on the Z sites for tracking and don't report issues, but 7% is quite a bit.

Since you already have the tires you can try them close to home and slowly build up your speed to see if your AWD light comes on, but other than that I surely wouldn't recommend them.

 

Oh I see. I guess I'm not going to risk it but just go with the 245 35 20 tire.

 

I usually run 255 35 20 on my 20's. Your speedo will lie to you if you go that much larger. Nothing sucks more than getting pulled over thinking youre doing 10 over, when its actually 14, and get a ticket.

 

The AWD models can't go more than 3% larger in diameter than stock. The OE diameter is apparently hard-coded in ECU or TCU.

 

Well you can go bigger/smaller overall.

The thing is it can't be more than 3% change between front and back. At that point they are rotating at different speeds and that totally confuses they system and can also potentially cause drivetrain damage.

 

I understand a 1% difference front to rear.

 

Yeah, w/ the AWD the 1% diameter variance from front to back when running staggered sets is the line that shouldn't be crossed. There are several cases where the AWD light will come on when going over 80 mph on sets that exceed 1% diameter variance. With RWD that line is commonly drawn at 3%.

There is a gray area as far as how much you can go over/under oem diameter when running a square setup, but again, 7% seems like you'd really be flying too close to the sun