Anyone running 245/45R18 on a 2013 R-spec Sedan?

[scooter]

Wondering if anyone has run 245/45/18s on a 2013 5.0 sedan. Diameter is 2.2% lower than stock (at least the 235/45/19 "stock" and not the 245/45/19 "summer tire option" stock). I like the idea of effectively running slightly shorter gearing with the drop in diameter, but don't want to trigger ABS or tire pressure warnings.

Also, any thoughts on what should be considered the "baseline" tire size for the 2013 R-spec? The 235/45 and 245/45 sets were both offered, but of course the 245's are taller by ~1%.

The alternative is I could run 255s... but that feels like overkill (on 8" rims I would be within the supported width range... though at the limit).

As for why the 18s... well, i would run 17s if they would fit... I want to cut as much unsprung weight as possible, and with 18s should be able to shave 40-50 lbs. from the car.

Thanks for any thoughts.
- Scooter

 

[Rey]

I had a '12 RSpec, which rode on 19" 245/45. I looked at tire weights and unsprung weight also. I am not sure 18" rims will fit the RSpec as the RSpec has larger brakes. Best to do some trial fitting before you commit yourself to the expense of smaller rims and tires.
I checked tire weights at TireRack, and concluded for myself that the differential between tire weights was not worth the expense. I might notice a difference at a track, but not in daily driving. The 245/45 is a common tire and there are many more choices available than say 255/45. My present car is a Equus which has 245s in front and 255s in rear. I am running 245s all around, which I think may increase oversteer a bit. In my geezer-style driving I have not noticed a difference.

 

[scooter]

Thanks, Rey,
I appreciate the thoughts. You are correct, there are more 245 options than 255. I *believe* the 18s will fit based on TireRack.com, but extra due diligence certainly would not hurt.
In my prior platform (Volvo S60R, ~3650 curb weight IIRC), I could feel the power (to the ground) difference and change in responsiveness when I dropped 8 lbs per corner. It certainly isn't anything like a 10% increase, but I noticed.
My R-spec has OEM 19s with 235/45 winter shoes on now. A third option would be to stay with 235/19s in summer shoes until I get used to the platform. First RWD for me, I've been in AWD land since the wrx came to the US in '02. First NA versus turbo for me since that time as well. I take delivery in a few days and cannot wait.

 

[mfaile]

Running the 245's with no issues. Like the meatier look.