vertrkr

Joyride posted this GL accessories guide in another post, not sure where he found it or if it's for US models. It lists some 18" wheels on page 7 that I'd like but I'm dubious if they really fit.
http://www.daimler.com/Projects/c2c/...e_GL_Class.pdf

Wheel: 8J x 18 ET 56.5
Tyre: 265/60 R18
A166 401 1502 9765

I called a mb parts guy and he said he found a reference to M class for them but nothing on the GL, strange. The owners manual even mentions some 18" wheels so guess some will fit. The guide spells tire the euro way so pretty obvious it's not for US but I can't imagine the brake/caliber dimensions would be different for non-US models. I'm probably the only guy that wants smaller wheels but the tire selections are so much better in this size.

Steve Maislin

18" fits the 2013 GL350, but not the 450 or 550. Large front brake calipers will not allow it. I believe this is all spelled out in the manual.

vertrkr

Thanks Steve. Now I'm thinking this might not be a great idea as the 18" has .4" smaller tire diameter than the 19" which will result a slower speed than indicated by the speedometer. Not a huge deal but I wonder if it would effect the radar collision prevention system and alike. Not sure if the car can dynamically calibrate for different tire sizes or if it is a set factory calibration.

Steve Maislin

If you can use the 18" you would use a taller tire on the smaller wheel. The overall size would be the same regardless of wheel size as it is the tires that provide flexibility. From my perspective, the best thing about the 18" would be for snow tires. But, like I said, you would have to make sure your model of the GL can accept them. I use 19" and I like them because they are far less apt to get dinged by a curb. Yes, some like the low-profile tires, but they ride stiffer and put the rim of your wheel closer to the ground.

vertrkr

That's usually the case but MB listed the tire size for that wheel at 265-60-18 which is .4" smaller diameter from the stock 19" 275-55-19. I'd go with 18 if it was an exact match since I don't know enough if that mis-match would cause any issues.