3MB -- Off topic, love the way you think through problems. What do you do for a living?

Gentlemen, a quick update:

1. Will go with Rohana and accept some poke -- estimated at 11-12MMs.
2. Once the wheels are installed, I'll post pictures.
3. I'll confirm once I know there are no rub issues up front with 255/35/20.
4. If there's sufficient clearance, I'll order the oem sport suspension springs in and solve this mystery once and for all. Debating between oem and eibach but will stick oem. Oem is supposedly just under an inch, eibach just under an inch as well.

Open questions:

1. Is one inch drop with my wheel/tire setup going to rub? Mb3 -- any guesses?
2. Is oem actually a one inch drop? Folks say it is half an inch but looking at pictures, there's no way. I would guess it is 1-2 inches.
3. Should I replace shocks while I'm lowering?
4. I wonder what we could learn if I just ordered the non sports springs and the sports springs from mb.... I want to say not much as uncompressed and compressed length are different creatures.

Small development:

As I dug into the SL550 Sport Suspension... it's more than just ordering the springs:

http://www.benzpartsdirect.com/auto-...uspension-scat

It includes -- per the link above, at least specific sport struts, springs, and stabilizer bar.

The plot thickens, am having a conversation with mbpartswarehouse -- I confirmed at the VIN # level whether the sports springs were on my vehicle.... here's part of the response:

"They are not the springs on your car. I show the fronts to be part number 231 320 11 04. On the rear springs, I don't show them to be able to exchange. Could it be built into your strut ?

That being said. I can get them here in about a week (they are coming from Germany) I will send you a quote for the parts and you can decide then."

I love that someone is taking the bull by the horns to figure this out. I hate the ride height of my '13 with the Sport Wheel Package and look forward to finally hearing a good solution.

Just a quick reminder that the title of the thread was the "cheapest/best option for lowering the R231"

The sport suspension springs will take the car down from it's SUV-level height in the US to what I consider stock height. Something I would have expected the car to look like coming from the dealer.

It will not look lowered. Anyone wanting lower than stock, you will have to go for 3rd party springs.

Unfortunately I haven't taken many pics of the SL's we drove in Europe but here is one from a couple of years ago...
Different wheels and/or wider stance will make a huge difference as can be seen on some other members pics.

https://cimg0.ibsrv.net/gimg/www.mbw...96d5145549.jpg

I have been researching aftermarket wheels for over two months and have read posts from Wolfman, 3 MB's and spoken to countless wheels salesmen. I too wanted to go 20" front but did not want to do the 245/35 front tire. I just ordered a set of Vossen x Work wheels and reluctantly went with the 19" fronts.

I have the SL 63 which has ET 27 front and 48 rear. Based on my measurements the 255/35/20 front will be very tight and may rub. If you jack up your car and slide your finger in there you will see that you have 1/2" at the very most to play with before you hit the upper control arm bolt. This is why nobody recommends the 255/35/20 tire but will advise you to go with the 245 or 255/30/20. Mercedes engineers must have only felt comfortable keeping the tire at 255 so they only offer the 19" wheel as an option with the 20" rear wheels.

ransomed12 let us know if you have no rub with the 255. When do you expect to have the new wheels on your car. I may put my order on hold if you experience no rub.

Will install Wednesday!

do you mean half an inch of width or height before hitting the control arm?

SL63 is significantly lower than SL550 (in the US). I know that 245/35-20 fits front of SL550 with room left, hence am confident that 255/35-20 (diameter of which is only about 5mm taller) should fit stock hight SL550 without any rubbing. The same (255/35-20 front not rubbing on SL550) might not apply to much lower SL63. Speaking of which, "recommended" 245/30-20 front, should not be fitted to any SL. If one wants to stay stock diameter - then 255/30-20 front, for those with a little more flare but still within conservative parameters - 265/30-20 front.

For SL550 I chose front 245/35-20 to successfully cut on tire gap to the point where I'm happy enough with the front's look. Rear is a different story - going with 285/30-20 still leaves a lot to be desired (yes much better than stock's same tire in 19", but not good enough). I decided agains using 21" in the back, and will try 295/30-20 PSS when tires are due for replacement.

Height since you are going to a 20"

I feel 20" wheels front/rear are desired , just call some companies that offer these on a regular basis. Renntech, Brabus, etc. or HRE vendors and have them tell you their recommended tires/wheel offsets.

All that info should be easy...

The SL 63 upper control arm bolt is in the same position as the SL 550 regardless of ride height. The 245/35's are recommended when people such as myself do not want to go to a 30mm aspect because of the chance to dent the rims. The SL is no lightweight.

Hopefully we find out on Wednesday that the 255's don't rub. It will be VERY tight if they don't.

That's why I am and have always, used 245/35-20 on front on SL and CLS (and W211 E). Many, however, have used 255/30-20 (and even 245/30-20 as you were told elsewhere, even thought its incorrect for SL/CLS/E) on front of heavier CLS63 and E63 with no issues. As I've said before, 265/30-20 has sufficient load capacity and a bit of extra sidewall (as compared to 255) to handle all the above and fits with room left, while providing performance benefits over 245/35-20.

[QUOTE=Sunline;7026026]The SL 63 upper control arm bolt is in the same position as the SL 550 regardless of ride height./QUOTE]

Interesting. I do not have picture of stock SL550, but...

the first picture below is of my SL550 with 245/35-20 tires - about 26.75" diameter;

the second picture is of the identical area in 2017 SL63 that I just snapped at my dealership with stock 255/35-19 or about 26" diameter.

The gap appears identical now, which means that it was much greater on SL550 before (probably by at least 1/2") I installed 20mm or about 0.8" taller tires. Which tells me that 255/35-20 should fit SL550, but not SL63 (it seams that even 245/35-20 will be a tight fit on SL63).

Guess I am confused as to what the fuss is all about...

Here is what Brabus is using: 20" wheels, the standard front wheel configuration:

9.0J x 20H2 ET 25 using tire size: 255/30 R20(-XL)

Same tires for 8 1/2" wheels. This is the only 20" tire size they use.

Same for stock or lowered springs or ABC

What's new here? See my above posts. They all "recommend" stock tire diameters of 26" for front fitment - for 18" its 255/40, for 19" its 255/35 and for 20" its 255/30.

Point you probably missed is that "people" do not want to use profile of 30 front and 25 rear, hence "people" use 35 front (most 245/35-20, but some would like to know if 255/35-20 will fit) and 30 rear (most 285/30-20, including yourself, and some 295/30-20).

I've had 16 different (half of them different Es) in the last 18 years. Each with multiple sets of rims/tires. I still have all spacers made in every size and many bolt sets in mms increments. I've tried it all. When I deal with TireRack, I tell them the fitment I want and not what their database says fits my applications.

I suppose you are right, I must have missed that "people" don't want to use these sizes ;)

Since this thread covered wheel gap and stance, Sunline's concern seemed about rub.

I used Brabus as an example because this is based on a German tuner that requires TÜV approval for all wheel/tire configurations in Germany. Unlike the US where you can do just about anything you want, in Germany it's more restricted.

The configs are approved & tested and this way covered by insurance in case of accidents (wheels/tires are actually added to the legal vehicle papers if not stock)

That said, the only config that was approved for Brabus rims are the sizes/offsets I mentioned. No other tire configs. No rubbing will occur in any circumstance.

[QUOTE=threeMBs;7026437]3mb -- want to guesstimate the amount of vertical space? also what is your tire pressure?

i will return with pictures on wednesday.

3mb
Based on your pictures it appears to me that your SL is not identical, but about 3/8" taller than the SL 63. Again, lowering the front end does not change the distance between the upper control arm bolt and the tire.

After seeing your pics I do think thought that the 255/35 will indeed fit, just very tight

Ransomed
Did you get the new wheels installed today?

Before I answer about whether my 255/35/r20 Pilot Super Sports fit, the caveats :)... my tires had wear on them/were used previously, the tire pressure was at 35 psi, and were mounted on 9 inch rims from Rohana. Your mileage may vary, use this information at your own risk, my specific tires and wheels may have been anomalies, and I take no responsibility for any decision based on this information/you take all responsibility for a decision based on this information. Etc. etc. etc. etc.

:) The tires fit, barely... barely...barely...barely.

This confirms what I said before - 255/35-20 will ("barely") fit SL550 and because of very tight fit on SL550, will not fit SL63. Also as stated above, while 245/35-20 fits SL550 with room, it fit be a very tight fit on SL63.

Sunline, why are you set agains running 245/35-20 upfront in favor of 255/35-20? The difference in sidewall is negligible.

Thanks Ransom I figured you would have about a 1/8" of clearance.

Since my SL63 has the identical clearance as the SL550 I believe the 255/35 will clear but I think it is just a little too tight for me to be comfortable running it that way. I will just stick with the 19" up front with 20's in the rear.

3 MB- I don't want to use less width up front than the stock 255, especially since I am going to a 295 rear (trying to gain a little traction with 664 lb/ft of torque) If I went 245 front, 295 rear it would promote even more understeer.

Post up some pics Ransomed!!

Understeer can be controlled with tire pressure - I'm using identical tire pressure of 40psi front with 245 and rear with 285 (SL550's stock 255/285 is 35/42). You could run 42psi front with 245 and 38psi rear with 295. If I were as confident as it seems you are that 255/35-20 would fit SL63 without rubbing, I would certainly try it. "What do you have to loose"?