Not the recommended Aspect Ratio
Thread Starter
Newbie
Joined: Jul 2021
Posts: 1
Likes: 0
GLC 300
Not the recommended Aspect Ratio
So I know the larger rims debate has raged for years. I have a more nuanced question. I currently have 19 inch rims and 235/55/R19 tires on my 2019 Mercedes GLC300. I am considering replacing them with 20inch rims and putting 235/55/R20 tires instead of 235/45/R20 tires. I think increasing the aspect ratio should account for 'ride comfort'. Any issues with this?
Newbie
Joined: Jul 2021
Posts: 6
Likes: 1
GLC
By increasing tire circumference, ride quality will def improve and you will gain 23.5mm ground clearance.
The only issue I can think of is the Speedometer reading will not match actual speed.
For example if you're driving at 60mph, the speedo will read 56.32mph
You can check out more details on www.willtheyfit.com
The only issue I can think of is the Speedometer reading will not match actual speed.
For example if you're driving at 60mph, the speedo will read 56.32mph
You can check out more details on www.willtheyfit.com
Junior Member
Joined: Mar 2019
Posts: 32
Likes: 8
GLC300
I believe the normal tire size for 20” wheel is 255/45 not 235. So if you go to 235/55/R20 is an increase of 1” in diameter (about 1/2” in ground clearance). As Hanger mentions this will throw your speedo off. It might also rub when you hit bug bumps especially when turning. If you were actually think about 255/55/R20, I think you will encounter lots of rubbing.
MBWorld Fanatic!
Joined: Mar 2016
Posts: 1,040
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From: Melbourne, Australia
2016 GLC 250d AMG pack, 2017 GLC Coupe 250d AMG pack , 2002 BMW 330Ci convertible, 2021 BMX X1 sD20i
Original settings, in both 19” and 20”
=============================
19"
5-Spoke Wheels
235/55 R19 on 8 J x 19 ET 38
R02 (All-Season Tires), R66 (MOE
———————————————
20"
AMG Multispoke Wheels
255/45 R20 on 8.5 J x 20 ET 40 (Front) 285/40
R02 (All-Season Tires), R66 (MOE
=====================================
=============================
19"
5-Spoke Wheels
235/55 R19 on 8 J x 19 ET 38
R02 (All-Season Tires), R66 (MOE
———————————————
20"
AMG Multispoke Wheels
255/45 R20 on 8.5 J x 20 ET 40 (Front) 285/40
R02 (All-Season Tires), R66 (MOE
=====================================
