Baby G

Anyone know the offset for the GLK?

I am debating 21-22's, but will start doing more reseach on rim choice once I get delivery. For those who have modded their rims, can you please post pics. Was thinking of a staggered setup, now not sure how that is affected with AWD. Decent lip would be nice... Open for everyone's two cents... If you have seen some good rims, please feel free to post links, pics, etc

Thanks

PDXGLK

You might give the Brabus website a look.

http://www.brabus.com/en/raster.php?...51&modell=8152

Even if they don't have one you like, they list width, diameter and offset for rims to fit you GLK in sizes 18-22".

drcollie

Pull off a factory wheel. The offset will be stamped inside the back of the rim, typically it well have "ET" in front of the offset value.

Baby G

It would have been easy if I had delivery which I don't as of yet...

Baby G

Thanks for the great link, I'll check it out...

Donutboy

here's my 22s

EnigmaAW

on the back of the factory 20's, it says the offset is 40. i just bought some 22's and here is a list of some important info that may help when shopping around.....
-bolt pattern=5x112
-offset=35-40
-hub bore=66.56
-factory wheel bolt=12x1.5x17mm, ball seat
-must swap factory TMPS to aftermarket rims, or buy new sensors
-can only run staggered lips, not staggered width because of 4matic
-most important..........get what YOU like!!!

ben-c

Actually, just as with Xdrive from BMW, you can run staggered width. GLks in Europe come with a staggered setup.

Baby G

Thanks eh... Can you PM me links... I really like the ones you have posted...

MilesBFree

With a staggered offset front/rear, you will not be able to rotate the tires easily if you have unidirectional ones.

Normally on a car that has the same tires and wheels front/rear and non-unidirectional, you would rotate diagonally when it was time to do so. If the fronts and rears are the same and the tires are unidirectional, you can rotate the tires by swapping them front to rear on the same side.

On my RX-7, I have unidirectional tires and different sizes front to rear (265 vs 285) and would have to take the tires off of the wheels and have them remounted on the opposite side (i.e.- swap right and left on the same axle, so the outside of the tire on the left is now mounted on the inside on the left wheel). Luckily, I mostly drive it for autox and track days, so the tires wear out long before I would need to rotate

MilesBFree

A clarification on running the same offset F/R: the RWD drive GLKs have this set up. The 4Matics have the staggered offsets. If you have a 4Matic, I would investigate what effect the different offset up front will have. If you go with wider wheels and tires, you may get some rubbing, especially at full steering wheel lock (turned all the way to one side).

Also, if you go with wider wheels, you will likely need a different offset. Keeping the same offset with a wider wheel will increase the backspace (the amount of wheel inboard of the mounting surface on the hub).

As you go to wider and wider wheels, at a certain point the wheel and/or tire will hit something when turning. The something could be the fender lip, the shock or spring, the wheel well, etc. The key to finding the right combination is really trial and error. Which is not cheap. The best bet would be to physically take the car to a place like the Tire Rack or other reputable shop and have them try out a few combinations.

With the RX-7, the online community tried a variety of combinations until we hit one that had a very small clearance at the fender lip, and almost no clearance at the spring, but it did work. Backspacing measurement was the key, not offset.

I think PDXGLK has the right idea - see what has worked for others, especially the respected tuners such as Brabus.

EnigmaAW

everyone i contacted, said a 4matic glk can not have a staggered setup because of the wheels not rotating at the same rate? but i've see e-classes with 4matic and staggered? either way, i 'd rather run even widths so i can rotate the tires easily. which i'm doing 22x9's, 265/35/22, et40

MilesBFree

I think the definition of "staggered" needs to be in context for veerodder's question.

Offset has nothing to do with rotation - that would be diameter. So if the people saying that different diameters front to rear will make the tires rotate at different speeds, they would be correct. If they are saying different offsets will make them rotate at different speeds, that is incorrect.

The reason it is not recommended to run different diameters front and rear on a 4WD or AWD car is that the transfer case will bind or have excess load since it is made to drive the wheels at the same rates front and rear. Actually, it is not clear to me if this would be an issue or not, as the front wheels with smaller tires might simply just rotate faster and therefore not bind the transfer case. I am really not sure on this one, but my guess is this is where the concern lies.

That issue is only for diameter, offset would not have anything to do with it.

The offset issue would be related to the extra driveline parts in the front wheels that a 2WD car does not have. The offset might need to be decreased to account for the extra distance from the car's centerline to the wheel hub mounting face (where the back of the wheel mounts). In effect, the extra parts from 4WD will push the wheel farther out than the 2WD version.

Having the wrong offset will cause more load and therefore wear on the wheel bearings and potentially other parts in the suspension and possibly steering.

Another issue with having different offsets front to rear is the tire rotation issue (maybe this is what they meant, veerodder?). You can not rotate the tires front to rear if they have different offsets as you will run into the bearing wear issue, and the tires may also rub on the body or suspension components.

For the following discussion, the definition of uni-directional tires means that they are designed to only rotate in one direction - you will normally see an arrow indicating the direction of rotation on the sidewall.

In the old days before uni-directional tires, you would rotate the front right tire to the left rear. And the left front to the right rear. etc. And if a full size spare, it would go into the rotation and another tire put into the trunk. That way they would all get somewhat even wear.

Now that most (sport) tires are uni-directional, you usually rotate them from the front to the back, and that's it. e.g.- front right goes to rear right. No diagonal rotation. This depends on a couple of wheel dimension measurements... The offset, width, diameter, and tire size must be the same from front to rear so that when you rotate the tires, the fronts and rears are identical and no issues arise form moving them front to back.

As an example, on my RX-7, I have to have the tires removed from the wheels and remounted in order to rotate them. The fronts are 265 width, and the rears are 285s. I can't just move the front right wheel to front left, since while the tires are the same size, they would then be rotating in the wrong direction (the uni-directional tire issue). I can't move the right front to right rear either, since the fronts are narrower. So off the wheels they must go in order to rotate them. As I said above, they usually wear out before I would need to rotate them anyway, but this rotation process is the correct one.

MilesBFree

Oh, as I also mentioned above, the 2WD GLK has the same offsets front and rear, so the tire rotation is simple - the right front goes to the right rear. And the left front to left rear.

The 4Matic cars would need to have the tires removed from the wheels and swapped left front to right front, and right rear to left rear (assuming the tires are also the same size).

MilesBFree

The Tire Rack has a better explanation than I may have given, plus they have diagrams of the rotation patterns:

http://www.tirerack.com/tires/tirete...jsp?techid=43&

Sample:

MilesBFree

The diagram above showing the wheels moving from left to right on the same axle obviously implies that the tires have to be removed from the wheels.

NYCGLK

no, it says they are non-directional

NYCGLK

are you talking about stock wheels? What's the source for them having different offset, I'm pretty sure all 4wheels are the same on 4matic. So rotating would be front to rear.

EDIT: Just checked tirerack for wheels and front and rear have the same offset 45 for 20's and 48 for 19's. They do offer optional wider rear fitment, however GLK in stock form don't come with staggered setup. Not sure about 2WD, my guess it's the same as 4matic. I'm guessing wheel set up is the same for US and Canada.

MilesBFree

The source for my info was the dealer.

My car is 2WD (not much use for 4WD here in the Southern part of the US).

When we ordered the 20" split-spoke wheels, they needed to determine the correct offset since those wheels are offered in two offsets. Their parts guy tried to look the wheels up in their system, but it did not say for 2WD cars. He made a few calls to MB USA, but could not get a definitive answer.

He said he was sure the 4Matic cars had different offsets, but was not sure as to the 2WD, but suspected that it had the same offset F/R (unlike the 4Matic).

So they just waited until my car showed up, measured the wheels, and then ordered the split-spoke ones to match.

Now, I can't say that the wheels that were on the car were correct (which is what this is based on).

Ours had the Appearance Package, and it is possible that this did not account for differences with the 2WD car. i.e.- the Appearance Pkg had wheels appropriate to the 4Matic model.

All I can say for sure is my 2WD GLK has the same offset front and rear. The dealer'sparts guy did say he thought this as he expected and he thought it was correct for the 2WD, but that the 4Matic had the different offset between fronts and rears.

Can anyone go out and measure a 4Matic's offset on the front and rear? I am heading out to do so for the 2WD...

NYCGLK

I think veerodder didn't say anything about rear and front ones having different offsets and he has 4matic. Per him +40 is offset on stock 20's.

Also just using my logic, usually AWD cars have the same wheels all around (BMW is one exception I can think of) and RWD cars might or mignt not have staggered setups. If 2WD GLK has the same wheels all around, I don't see why 4matic would have different wheels.

I'd also believe tirerack before dealer, when it comes to details like this dealers know $h1t.

MilesBFree

OK, I measured the wheels on our 2WD GLK, and found that the fronts have a smaller backspace than the rears. I measured them while still on the car, so the measurements were not exact. However, I found about an inch of difference, which can't be explained away by measuring them on the car.

So we could have at least 3 possible explanations:

1. The dealer was correct and the 2WD cars are supposed to have the same offset front and rear.

2. The dealer was correct about the same offset F and R, but the Appearance Pkg wheels installed (with different offsets) was wrong, i.e.- the wheels installed as part of that pkg are incorrect for a 2WD car. i.e.- the Appearance Pkg is the same for the 4Matics and 2WD cars but should have two versions, one for 4Matic and one for 2WD. Actually, if the 4Matic and 2WD cars are different, then there MUST be 2 versions of the Appearance Pkg.

3. The dealer was wrong and the 2WD cars have a different offset front and rear. This is my bet since they claimed to have measured the offset before ordering my 20" split-spoke wheels, but clearly they didn't since there is about an inch difference between the front and rear wheels' offset.

I need to call the dealer back since they sold me 4 identical 20" split-spoke wheels with identical offsets. These may be the correct wheels for a 2WD and the Appearance Pkg was wrong. I need the dealer to take over at this point and make it right.

MilesBFree

More info on the 20" split-spoke wheels: the info cast into them is:

Size: 8 1/2 J x 20H2
Offset: ET45
Part #: A2044012402
Cromodora SpA (Italy) is the manufacturer.

The part number is the same as on the box, except there are spaces in it so the number may be looked up also as: 204 4012 402

NYCGLK

Nothing wrong with that.

I'm 99% sure all 20's have the same offset.

This seems a good source:
http://www.service-shop.mercedes-ben...ewPageNumber=0

No mention of 2WD or 4WD or different offests for 20's. Both US and Canadian versions have 45 offset.

They also have wheels for staggered setup, but we don't get in US.

MilesBFree

The 20" wheels have different offsets on our car with the Appearance Package (the 20" wheels that come t=with that package). We are in the US.

I need to get the dealer to find out if this is correct for our 2WD GLK.

NYCGLK

What are the offsets? Did you take the wheels off to check? Just because there is different distance between the wheel and the body behind the wheel doesn't mean they have different offsets.