I am interested in running a square setup on my e550 4matic. I have a few reasons behind my desire to do so.

The obvious is the debatable wear to the transfer case at various tire sizes and the necessity to run a 25 aspect rear tire to maintain tolerances for rolling diameter.

Part 2 is that the pilot super sports offer a 30k mile tread warranty if run square. (Due to being able to rotate them). This is appealing to me as it is a top notch tire and having some piece of mind on longevity makes them a more viable option.

The question I have is due to my lack of knowledge when it comes to offsets and how the wheel sits in relation to the vehicle.

For instance. One fitment that I love the look of is the 20" Velgen 9 et 32 front and 10.5 et 42 rear.

My question is if I ran a 9 et 32 all the way around with a 10mm rear spacer, would the face/flushness be identical (offset measured from the face of the wheel not inner edge of the tire)? Or does the offset have more of a balancing point within the wheel itself and widening the rim would create an overall change of balance? I know I would loose some of the concave appearance but that is a variable I can tolerate in the grand scheme of things. The trade offs seem worthwhile. I do not feel my driving style would warrant the need for the far greater rear tire width and the PSS performance advantages are appealing. Runner up is the evo v12 or perhaps extreme contact dws. I'm going with a 245/30r20 all the way around if I do go this route. Likely with a set of the vessel vfs2 in Satin bronze. I've had my eye on a slick set of forged wheels used that are appealing to me as well, but I keep flip flopping on my desires.

Once I understand this, I'm sure making the correct decision will be much much easier.

I'm pretty sure I grasp this, but have had some really dicey answers from people I thought would know. I trust you all fully!


Thank you.

I currently run spacers. I have had zero issues with them with a small exception of an idiot rotating my wheels stripping a bolt.

Please poke holes in this concept. Thank you!

 

32 offset sticks out farther than 42 offset, therefore the correct answer is to run 42 offset all the way around, with spacers in the rear if you want them out wider. 9" wide with ET32 in front will stick out too far. Stock offset on the 18" wheels is 48. Offset also needs to change as wheel width changes, as it's based on the center line of the wheel. Here is a great calculator to see the difference between two different wheel/tire setups:

http://www.rimsntires.com/specspro.jsp

 

I have 9" et32 for my fronts and they poke slightly... but my 10.5" et42 rears also poke the same amount.

And I can watch them spinning in the side mirror as I'm driving. Totally distracting, possibly dangerous, but it's mesmerizing.

 

If you don't want "poking" which looks bad IMO and could lead to rubbing, then you need ET in the 40s up front with 9" or less wheels, and with 10s in the rear, ET should be in the 50s.

A square setup at 9" wide with ET42-45 would be about perfect, spacers could be added in the rear.

 

To each their own. I also don't like the "Mexiflush" look, but the way the fender lines on these cars go, a little poke doesn't look bad. As far as rubbing, the previous owner of the wheels didn't have any when they drove conservatively, except for occasionally on the more technical speed bumps, but you're not supposed to be playing Dukes of Hazzard in these cars anyway.

So if the OP doesn't want poke, then yes, what you said would be ideal. I agree that he should start with et42-45 and space from there, for a square setup. I think I read somewhere on here that 10.5" et35 in the rear is flush with the fender, which follows the logic of 9" et45 being flush.

 

10.5 with ET 35 would be massively poking out. Larger positive offset is needed with larger wheel width to move the center line inward. I don't see anyone running 10.5 really. You might run into back-spacing issues at that point with the proper offset.

 

You're right; it might've been some other width that they were talking about. In any case, I never could find that thread again later on when I was wheel shopping. It's possible I made it all up lol

 

@Ed99 was running the Velgen vmb5 (9" 32 front, and 10.5" et 42 rear) with no fender mods. (sorry for stealing your photo)

I find this fitment to look perfect for my tastes.

What I'm trying to determine would be how to run a square setup and retain the same fit so to speak. With widths/centerlines varying, that is where I get thrown off.

Currently I'm running the stock 48's (48 et with front 15mm and rear 20mm spacers). There is a bit of extra room to play with before becoming completely flush, and I'm not yet into the "poke".

so rear essentially right now is 8.5 et 28 and front 8.5 et 33.

I appreciate your insights and sharing your knowledge.

 

If you change the width of the wheels, then the offset numbers are not directly comparable. It's a formula including the width. Use the calculator posted earlier to compare the current setup to a different setup.