different sizes front/rear - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Rob99 · 09-23-2022, 11:04 AM

My 2015 ( previously owned ) has the 20'' wheel option, i noticed on the front wheel liners there are rub marks that had to happen while the original owner had it,( i have no rub noise happening now) so that led me to look at the tire size and found the fronts are 245/40's which is not the OE size 245/45's.
So i looked up a tire size calculator, and the 45's are larger overall and i can see they have a very thin or narrow side wall, also the rears (OE size) are a different brand and tread pattern than the fronts.
Should this be of any concern especially with the tread pattern, speedo or ABS? I'm guessing this was a 'look' thing with the lower profile.
Not an expert on tire stuff so any thoughts are appreciated.

245/40-20 245/45-20 Difference
Diameter inches (mm) 27.72 (704) 28.68 (728.5) 0.96 (24.5) 3.5%
Width inches (mm) 9.65 (245) 9.65 (245) 0 (0) 0%
Circum. inches (mm) 87.07 (2211.68) 90.1 (2288.65) 3.03 (76.97) 3.5%
Sidewall Height inches (mm)3.86 (98) 4.34 (110.25) 0.48 (12.25) 12.5%
Revolutions per mile (km) 727.66 (452.14) 703.18 (436.94) -24.47 (-15.21) -3.4%

KillboyPowerhead · 09-26-2022, 07:06 AM

OEM fronts on the 20" wheels (RS and SS) are 245/45 (275/40 rears which works out to the same diameter as the fronts). Is the car lowered? If not maybe it was before they sold the car.

Rob99 · 09-26-2022, 11:39 PM

I'm sorry for the confusion (on my part) your correct about the 245/45 front OE size.
I have 245/40's on the front now, (i corrected my post above).
I don't see any evidence that the suspension was lowered or altered in any way, of course it could have been and then retuned to stock?? I'll never know at this point and TY for the reply.
My concern remains about the size in front and the different brand and tread patterns between the F & R. why was it done? availability? what did it accomplish? a sidewall look/appearance?

09-23-2022, 11:04 AM	#1
Rob99 I’m Magik a physco dog Drives: '15 1LT/RS & '23 3LT/RS Join Date: May 2016 Location: N.J. Posts: 251	different sizes front/rear My 2015 ( previously owned ) has the 20'' wheel option, i noticed on the front wheel liners there are rub marks that had to happen while the original owner had it,( i have no rub noise happening now) so that led me to look at the tire size and found the fronts are 245/40's which is not the OE size 245/45's. So i looked up a tire size calculator, and the 45's are larger overall and i can see they have a very thin or narrow side wall, also the rears (OE size) are a different brand and tread pattern than the fronts. Should this be of any concern especially with the tread pattern, speedo or ABS? I'm guessing this was a 'look' thing with the lower profile. Not an expert on tire stuff so any thoughts are appreciated. 245/40-20 245/45-20 Difference Diameter inches (mm) 27.72 (704) 28.68 (728.5) 0.96 (24.5) 3.5% Width inches (mm) 9.65 (245) 9.65 (245) 0 (0) 0% Circum. inches (mm) 87.07 (2211.68) 90.1 (2288.65) 3.03 (76.97) 3.5% Sidewall Height inches (mm)3.86 (98) 4.34 (110.25) 0.48 (12.25) 12.5% Revolutions per mile (km) 727.66 (452.14) 703.18 (436.94) -24.47 (-15.21) -3.4% __________________ 2023 3LT RS Shadow Gray 2015 1LT R/S Blue Velvet Coupe. Previous: 2015 1LT Ashen Grey 2016 1LT Blue Velvet My entire life has been 'A Midlife Crisis' Last edited by Rob99; 09-26-2022 at 11:41 PM. Reason: corrected the tire size in the post.

09-26-2022, 07:06 AM	#2
KillboyPowerhead Drives: 2015 Z/22 Join Date: Aug 2015 Location: Ontario, Canada Posts: 931	OEM fronts on the 20" wheels (RS and SS) are 245/45 (275/40 rears which works out to the same diameter as the fronts). Is the car lowered? If not maybe it was before they sold the car. __________________ Overkill/Self Tuned; Mace Camshafts; K&N Typhoon Cold Air Intake; Ported 80mm Throttle Body/Intake Manifolds/Manifold Spacer; Solo Performance High-Flow Cats, Cat-back Exhaust; Vitesse Motorsports Throttle Controller; Elite Engineering E2 Catch Can; BC Racing BR Coilovers; JPSS Delrin Radius Rod Bushing Inserts, Sway Bars; Pegasus Aluminum Rear Cradle Bushings, Camber/Caster Plates; Z/28 Toe Links, Trailing Arms, Upper Control Arm Bushings, Rear Shock Mounts

09-26-2022, 11:39 PM	#3
Rob99 I’m Magik a physco dog Drives: '15 1LT/RS & '23 3LT/RS Join Date: May 2016 Location: N.J. Posts: 251	I'm sorry for the confusion (on my part) your correct about the 245/45 front OE size. I have 245/40's on the front now, (i corrected my post above). I don't see any evidence that the suspension was lowered or altered in any way, of course it could have been and then retuned to stock?? I'll never know at this point and TY for the reply. My concern remains about the size in front and the different brand and tread patterns between the F & R. why was it done? availability? what did it accomplish? a sidewall look/appearance? __________________ 2023 3LT RS Shadow Gray 2015 1LT R/S Blue Velvet Coupe. Previous: 2015 1LT Ashen Grey 2016 1LT Blue Velvet My entire life has been 'A Midlife Crisis' Last edited by Rob99; 09-26-2022 at 11:49 PM.