wyatt88

Hello All, coming from a 2018 GLS with the standard 19" wheels, I now have a 2024 GLS with the standard 21" staggered wheel setup. My question to those in the know, what are the advantages to having larger wheels, other than looks, which are important? Also what is the advantage of having the very wide rear wheels? I have heard narrower wheels/tires perform better in snow/wet conditions.

I live in a metro area where our tax money goes to anything but road maintenance. I have to say that my 2018 with the smaller and narrower wheels road the city potholes and huge pavement seams like a champ. The 2024 with the standard setup crashes over these pavement imperfections even with the air suspension.

My only other complaint about the 2024 compared to the 2018 is the wimpy steering wheel heat and the capacitive buttons on the steering wheel which randomly escalate the music when a turn a corner.

Thanks for any responses.

EWL5

I don't have an answer for your wheel/tire question (sorry!). Just curious if the music volume changes because your hand brushes the capacitive buttons or something else?

z28lt1

Larger wheels are primarily for looks as you mentioned. However, large/wide tires (particularly with the associated low profile/stiff sidewalls) will provide for better dry traction and handling (and the expense of comfort). Not surprisingly, those wide tires help with many of the tests that automotive journalists use in their testing including 0-60 times, braking distances and lateral handling with g's or figure 8 tests, which are important to some manufacturers.

wyatt88

Thanks z28lt1 for the explanation and taking time to reply. Personally any increased performance is not worth the harsh ride on lousy pavement, but I am sure others may disagree.

wyatt88

EWL5, I am sure that the volume level change that happens seemingly randomly is because of my technique of somehow brushing against the capacitive volume steering wheel button when turning. My sixteen year old son, who is in driver's training, points out my outdated hand position on the steering wheel among my many other driving 'faults'.

Thanks!

Scott Schmidt

On my 2022 GLS my hand has in the past brushed the RESUME toggle switch on the steering wheel while turning into a parking space, and the car immediately tries to accelerate back to 50 MPH. So that's a lot of fun when it happens!

streborx

Regarding the OP topic, 21" (or larger) wheels are primarily for looks that you and maybe 2 or 3 other people will notice. The price for all this attention and admiration is dismal tire selection, high prices, poor availability, compromised ride comfort, and risk of pothole damage. Staggered setups, that rule out tire rotation, make even less sense with an even smaller choice in tires, and especially in winter tires. But being on the back-order wait list for a set of snow tires in mid- February makes some folks feel special, I guess. My BMW came equipped with a 22" staggered setup (even worse, performance summer rated run-flats), and the first modification I made was changing them out to a squared-up set of 20" wheels with Michelin CC2s. I don't care what others think of 20" wheels, and my doctor tells me my testosterone level hasn't been compromised.

mikapen

I agree that staggered tires are for looks, since my 53 needs more front grip, but I disagree that big, grippy tires are for appearance only.

Tires are what provides that performance.

Sorry about your manhood concerns, but don't buy a performance car if you don't want performance!

Get a car with little tires, that are always in stock at Walmart for under $99.
It'll be a better match for your sensitivities, at least based on your post.

streborx

Agreed - when tire performance counts, big grippy tires are the way to go. But my BMW X7 is considered an upscale soccer-mom ride in some circles, even with its 4.4L TT 523 hp and increased top speed limiter. Performance tires on it seems to be like trying to make it respectable if I try to elbow my way into a Ferrari rally (lol).

jkaetz

Can't speak for the X7 but I appreciate that the GLS feels more like a car than a massive people mover. After ~5 months of ownership I only recently found its front grip limit on a wet roundabout. It absolutely provides more performance than needed but I appreciate the 21x10 front and 21x11 wheels. I'd certainly take the extra 1/2" of sidewall if offered but I don't see it making a massive difference. I do agree that going above 21 gives diminishing returns and a more limited tire selection but I suspect this will change as time goes on. There seems to be a never ending push to increase wheel sizes from all manufacturers. My guess is the larger wheel/tire combinations allow less rolling resistance ever so slightly increasing their CAFE ratings when multiplied by thousands of vehicles sold.

wildta

I always thought that rotational mass (like increasing tire/wheel size which typically adds to the unsprung weight), is known to reduce your gas mileage. Also because a larger tire typically might be wider as well and thus has more contact with the ground, it would have a higher rolling resistance.

streborx

The OE tires on my X7 were performance grade, optimum for dry pavement. Tread design and rubber compound are the critical factors in rain, snow and mud. The skinny 205 Blizzaks on my Jeep will push a plow loaded with snow uphill. The X7's 305's excel at spinning in place on a flat surface. Contrary to some beliefs, traction control cannot turn tires into something they're not.

streborx

Maybe in combination with mild hybrid systems there is some beneficial flywheel effect. How much is real and how much is imputed is anyone's guess.

jkaetz

This is kind of what I was thinking. More weight yes, but once it's moving the impact is negligible and the larger overall diameter will more easily roll over the road surface. We'd likely need an engineer to do the math for us and tell us if there's any statistical relevance or if it is just for marketing and looks.

DesertGolfer

I traded a 2020 GLS with standard 20" wheels and NON-runflat tires for a 2024 GLS with standard staggered 21" wheels with NON-runflat tires. While I don't sense much change in ride quality, the 2024 has greater directional stability due to the wider rear tires. The 2024 feels significantly better connected to the pavement.

What air pressure are you running with the front and rear tires?

nc211

We have the 21's staggered on our 2020. Definitely holds that rear end in place, which in a big SUV like this, is why I tolerate the $750 kick to the wallet every 25k miles to replace them.

What I don't like is the alignment MB puts on them, too kicked in towards each other, which I get it, adds to the stability factor. However when one wheel goes over say a lane stripe that is slick, the other immediately wants to push the rear over, causes a wiggle in the rear and throughout the car. Always has done that, even after a few checks of the alignment from the dealer and my Indi. I would much prefer the tire width be the stability factor only and less alignment influence.

wyatt88

Tires at 33. Is there a better number? Thanks.

nc211

That's what we've always run ours at too. Not sure what brand you have on yours? Our originally came with the Pirelli tires and switched over to the Michelins at 25k all around (I like Michelin better in general, personal preference).

DesertGolfer

My tires are also set to 33 PSI, which is just 2 PSI above the recommended pressure (displayed inside the fuel door). I find that 33 PSI provides good ride quality with decent steering response.