With a 16" rim, from what I have read and experienced, the following will happen:

1) You will have a shorter rubber side wall height and lower air volume for the same pressure - hence the ride will be be slightly to noticably more stiff/harsh feeling on bumps, partially moderated by tire selection.

2) Generally, the 16" rim will weigh more than the 15" rim, increasing unsprung weight and slightly decreasing handling. This handling decrease will be minor when switching from 15 to 16" diameters, and possibly offset by the improved handling feel of stiffer side wall - possibly even with a net improvement by going to 16".

3) The 16" wheel, even if it is not heavier than the 15" it is replacing, will have more of the mass at the rim, and will have greater angular momentum, slightly decreasing acceleration and braking times (Harder to get it spinning on acceleration, tougher to stop it rotating during braking). This is a relatively small effect.

4) The brake rotors and calipers will have more space around them for heat radiation, and depending on wheel spoke style, will probably have greater air flow, possibly better cooling.

5) The tires are going to cost more for a comparable rolling radius/width tire.

__________________
John

2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)

Click to see 87 300E

I have 15" tires on both my Benz's right now. I have one set of four winter tires (Blizzack's) on 15" rims. I am buying another set of rims for winter tires. What would be the advantage of going to 16" rims and tires, either for summer or winter driving. How will it affect milage, handling and ride in the cars. They are both the 124 body design. Any help or input would be greatly appreciated.

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Bob Morrison
92 300D 2.5 -197000 Miles
87 300D-170000 Miles The Californian
87 Volvo240DL-200000+MilesGrandson's Now

If you compare two tires of the same performance level, one of the 60 or 65 aspect ratio, and the other a 45 or 50, you will note that the taller tire (60 or 65) has a lot of circumferential belting reinforcing the sidewall just above the bead -- on really good handling tires, this circumferential belting may stiffen up more than half of the sidewall, so that only an inch or two has true radial flexibility. On a lower aspect ratio tire, the wheel is there in place of this stiff sidewall area, and the true radial part is just as big (or almost); the bottom line is that the difference in ride is not nearly as great as what you'd expect, since the air volume is usually balanced by the lower aspect ratio tire being wider, if it is rated for the same load, granting that many people who change to bigger rims fit tires of somewhat less load capacity because of lateral space limitations, and therefore have to run them at higher pressures for the same load.

Take an unmounted tire of each size and try to flex the sidewall with fingers inside and out, and you'll see the comparison that I mean.

in general, 16" winter tires will be more expensive than 15" ones.

also, the 16" tires will generally be wider than the 15" ones, and you want a narrower tire for winter, so the tire can dig in better through the snow.

i would use the old 15" rims for winter (so you don't care about salt corrosion), and 16" rims/tires for summer.

The best thing about aftermarket wheels is that it frees up lots of very nice OEM Mercedes wheels at good prices.



Ken300D

Thanks John. Good input!

My own observations are centered around my recent "minus 2" move on the C230. I ditched the 17x8" wheels and 225/45-17 tires for a couple reasons:

1. Ongoing costs of tires.

2. Attention the wheels brought to my car. (I'm aging...)

I was going to mount the 16" MB OE sport wheels with 205/55-16 tires this spring, when some 205/60-15 RE930 tires got dropped in my lap. Being the cheapskate I am, I readily accepted free tires, and promptly mounted them.

The main differences between 17 and 15's are:

1. The 17" wheel and tire combo is heavy, unless $$$$$$ forged super-light wheels are purchased, most 17" wheels are much heavier than the 15" OE wheels.

2. The handling/braking capability of the +2 set-up is higher, but not the huge increase that one might think. Racetrack results would be different, but on the street the performance increase is marginal, but fun to have.

3. 45 series max-performance tires are generally very noisy. If you value ride quality and quietness, don't go big.

4. Wet performance of tires like the Michelin Pilot Sport and SO-2PP is incredible. Braking in the wet was nearly as powerful as the dry.

5. On "low power" (non-AMG and non-V-8) Mercedes, the big tires have no, or even detrimental effect on acceleration. Increased rotating mass and adhesion far beyond the torque of the engine make it a boggy launch. Is boggy a word?

6. Wide low profile tires are terrible for following road surfaces. The lack of give in the sidewall creates this. I thought I needed an alignment constantly.


Well, lots of people can't believe that the stock 205/60-15 tires in an H-rated tire can come as close to the Z-rated Max-Perf rubber as it does. Here's why:

The stock MB suspension (and even my AMG suspension) is well tuned to the stock tire sizes. Increasing adhesion levels isn't the big jump it is with most cars as the MB already exploits the tires it comes with.

Non-AMG and non-V-8 MB's generally don't have the horsepower to exploit big tires in the traction department. If you put those RE930's on the C36 we owned, it would have been a major goof. But, on the C230, they work very well.

Do I miss the Max-Perf rubber? Sometimes. Rapid transistion corners bring out the lack of turn-in speed on the "normal" tires.

__________________
John Shellenberg
1998 C230 "Black Betty" 240K

http://img31.exs.cx/img31/4050/tophat6.gif

another advantage of 15" over 17" wheels is that you make no fuss about bumps in the road. With a 17" wheel, you worry more about denting the wheel.

Especially when driving on bumpy backroads (where the Benz's suspension comes into its own), the stock 15" tire has enough sidewall height to protect the wheels, and you can drive worry-free at high speeds.