EdenGLK

What is the difference between the 19" 10-spoke alloy wheels and the 20" 5-twin-spoke alloy wheels performance wise?

-Eden

webada

its not so much of the size of wheels but rather the tires that's equipped on them.

in the GLK case, its mostly appearance... in fact, 20" wheels will probably give you less off road capabilities and more road sensitivity.

MtnMachine

One added inch of wheel can make a difference in several ways, but the most noticable will be ride comfort. One less inch of wheel and one more inch of air cushion will make for a better ride on rough pavement or any bump etc. As webada points out, any off road will be better on 19s.

I bet the 0-62 kilometer test was done with 19s. 20s look great and grip well on corners in warm-dry SoCal, but one inch bigger wheel adds much to rolling mass and could add a tenth or two to 0-62 time. Only justification for 20s is "Cool Appearnce". Look fast, go slower. I really think 19" wheels are very attractive and more in proportion to car.

Most passengers can feel better ride on any rough pavement, but few people can feel a tenth or two difference in off line sprint. IMHO

DerekACS

In addition to inferior ride and reduced off road capability, the 20s are much more prone to curb damage, since the wheels stick out further (wider track) and there is less tire profile to act as a buffer.
One more consideration, it is presently impossible to find 20" replacement tires for the GLK.

Baby G

Tirerack.com has the sizes in stock now:

http://www.tirerack.com/tires/Compar...All&loadRank=2

Tire: Pirelli Scorpion Zero Asimmetrico - Size: 235/45R20 - Price: $280.00 (each)

Tire: Dunlop Grandtrek Touring A/S - Size: 235/45R20 - Price: $225.00 (each)

thebishman

The 7 spoke 20" wheel looks fantastic on the GLK; better imho than the 19", although the 19" also looks very good.

True that IF you intend to do some semi serious off-roading in the GLK then the 19" wheel would be a better bet; for traction purposes as well as being less prone to damage. However, the 20" wheel/tyre combo that I drove on, (the Pirelli's), produced a very good and acceptable ride, with excellent stability and control. There is still a decent amount of tyre between the road and the rim, hence there was very little harshness noted. I also think that if you are going to 'curb' a wheel, then the 19" wheel will only afford you a little more protection than the 20".

Bish

yualfred

fyi. 11% is how much more the height of rubber 19" vs 20".

DerekACS

Thanks for the update; that's good news for those with 20s.

Schutzen

I am with DerekACS regarding 19" vs 20" wheels...it could be a Canadian thing with the freeze / thaw cycle and potholes on the roads. I had an Audi with s "sport package" and very cool wheels (lots of rim and a little rubber) I actually started to prefer the snowtire ride in the winter vs. the summer sport package ride...maybe old age 35 too

glkowner

For those driving in winter conditions and debating 19" vs 20" rims I'll share my 2 cent opinion... I plan to run on 17" rims with winter tires starting next winter. I'll enjoy my good looking 20" rims in the spring & summer. Even if I had the stock 19" rims I would still plan to get a set of 17's as I'm a big believer in winter tires and improved stopping distance. The GLK has incredible traction in snow but 4,000lbs zipping accross ice can really benefit from tires designed to perform at -25C. The dealer recommends 17" rims for winter tires, I dont think you can put winters the 19's...I'm not 100% sure. I'm hoping to get the benefit of smaller rims for a good part of the year and the enjoyment of the 20" rims the other half of the year. Win-Win.

jamking

You can fit more snow in the 20"-bigger rims, fewer spokes. See photo I took tonight.

MercPlease

I test drove a GLK with the 20" wheels and it was really smooth still.

Schutzen

glkowner is right on the money...I thought the same thing, that I would get a dedicated set of snow tires on 17" rims and then go with the sport package. I was set to order the sport package and was then told I would not get the aluminum roof rails. glkowner you must work for Transport Canada or know something about the benefit of snow tires. Definitely snow tires are law in Quebec...I know Ottawa is super cold and in Southwestern Ontario we get tons of lake effect snow...snow tires...YES!

Baby G

+1 very well said!!!

I plan on the same thing, pickup a 17" Winter package, and keep my 20's for spring and summer driving.

MtnMachine

You Canadians never stop rubbing it in. Jamking's picture of his GLK in snow bank points out another reason the Canadian 20" wheels are not only better looking than the USA 20"s, but they hold more snow than ours.

When my GLK arrives in late May, I will show you Canadians. I will take pictures of my GLK, 10,000 ft up in California's Sierra Mtns at Mammoth Mountain Ski area, on a sunny, 50F degree day of skiing on a ten foot spring base.

Ballsofsteel

Tire: Pirelli Scorpion Zero Asimmetrico - Size: 235/45R20 - Price:
Price: $205.00 (each)

SD90

That 11% is only 1/2 an inch of rubber.

EVTee

I have to agree that the 20" still rides very smooth and it looks 10x better than the 19".

MBRedux

There’s lots of misinformation here…. Yes, if you plan to go off-roading, get yourself another SUV…. Now if you’re driving on paved roads like 99.9% of GLK owners, regardless of the wheel size you buy, the overall diameter remains the same. (It must remain the same to maintain the overall design geometry and calibration MB’s engineers designed into the car). Even the width of the tread remains the same, along with its offset so as far as the smaller diameter wheel being better suited for snow than the 20” tires (which can be bought ANYWHERE these days unless you live deep in the outback) don’t believe it for one second. It doesn’t make a difference. In almost all cases where you need snow tires or chains, most of us if not all purchased separate winter wheels and tires for the snowy season and switch back once the spring arrives.

A larger diameter wheel just means that the sidewall width (or height measured from the wheel to the top of the tread) of the tire is thinner, (because the overall diameter of the tire remains the same). This translates into less flexing of the tire’s sidewall when turning, thus better turn-in feedback and control when steering. Simply, the car will respond quicker to your steering input, it will feel more precise, less mushy!

The downside is as mentioned. The smaller wheel/tire will be only slightly less susceptible to road hazards such as deep potholes but it will suffer the same fate as the 20” wheels if you scuff them on the curb. Besides, the 20” look great too!

Good luck.

NYCGLK

Two things that make smaller dimeter wheel do better in winter.
1) Less wieght on the wheels always helps.
2) Taller sidewall has additional traction in deep snow and more flex of the tire is also benefitial.

clkcadet

Living in NYC I learned that no matter if you have 15" wheels or 26" wheels, you are going to get potholed unless you are super careful.

Wheel/tire insurance already paid for me in the past, and I will get them on future cars as well!

EnigmaAW

i think my 22's feel the same as my 20's.