milsons200

I am considering +2 from 17 inch factory wheel. Is there any down side in terms of performance after the upgraded ?

A friend of mine suggest me to upgrade a lighter forged wheel(17inch) and forget about +2, this in terms will improve performance and handling.

I thought as long as the overall circumference of the tyre stay the same, the performance should not be affected ?

Any thought on this ?

Hard to find a super light(18" ; less than 16lbs) and good looking wheels for the W204 ...... any suggestion ?

vcruiser

go for something classy and nice rather than for performance reasons.
because your car is pretty slow anyway since c300 and even c350s arent the quickest.

PoaMike

^Maybe he plans on modding it? anycar can be fast with the right intentions.

nil8r

The less sidewall the rougher the ride and the better the lateral handling. Typically larger wheels add more weight but not always. More weight would result in slower acceleration and breaking.

I think most people get larger wheels for appearance purposes and sacrifice the ride quality. Unless you are running on a track or racing often on the streets I dont see how the handling inmprovements could be significant.

white46

when people moves up to 19"s, it's mainly for looks.
if you want better handling, put new sway bars.
moving from 17"s to 19"s, performance wouldn't change much.

narky

I'm looking for one! Does anyone have 'em already?

oblu

Best performance upgrade for the money is new tires.

Besides that, shorter sidewalls are stiffer and flex less which provies better feedback ... completely useless in this car, the steering is too light to benefit from this much. That stiffness also results in quicker break away at the limit.

Besides that it'll ride a bit harsher, more so if you get heavier wheels than the stock 17s. Which isn't hard to do if you go cheap. Lightweight forged 19's cost some dollars. The suspension has to work harder to keep up with the increase in unsprung weight also, so you can get some funkiness going on in the ride. Not a lot if the wheels are light, a lot if they're heavy.

Even if the 19s are lighter, keep in mind that you're still pushing more weight out further from the hub of the wheel which creates rotational inertia. Which is bad for acceleration and braking. How much you'll actually notice this from the seat of your pants? Probably not much. Unless, again, you cheap out and get really heavy wheels. Then it'll feel like you've got two really heavy people sitting in your car with you.

But they look great. I've always ended up with 19s on my previous cars (I've run the whole spectrum of cheap and heavy to expensive and light). Probably won't with this one though; the amg 18s do it enough for me and I'm just not in the mood to drop the cash on this car like I did my others.

oblu

Sway bars are slippery slope. They just provide the ability to adjust the handling balance to your preferences. A poorly engineered bar can easily decrease ultimate grip at the expense of making the car feel like it handles better.

A well tuned shock/spring combo first is a better choice in my opinion. And then adjustable bars afterward to dial in balance.

Derspeed

19" wheels will have a negative impact acceleration and braking due to increased rotational mass. They will also increase unsprung weight. You will get improved turn-in with good 19" tires. However, it seems when people switch to 19" wheels they slap some Nankang tires on 'em totally defeating the purpose of a wheel upgrade; unless you're motivation is to just get big chrome wheels stuffed under your fenders for as little money as possible.

As long as the overall diameter of your combo is very near stock, your speedometer will remain accurate.

I have to agree with another member who indicated springs and struts are a better upgrade option than installing anti-sway bars. I have always believed that as well. A while ago I read that German car makers believe in making cars handle better with proper springs, struts and geometry and do not rely heavily on anti-sway bars. I can't remember the source. Sorry.

Finally: It doesn't matter how much horsepower your car has. Any car is more satisfying to drive when the handling is dialed in properly. Years ago I had 1995 Jetta with about 135hp. With suspension upgrades, it was a blast to drive. Taking curves faster doesn't reqire more horsepower.

milsons200

thanks everyone for you kind words

I guess i won't do much with the new ride till more tested suspension kits available on the market.

e.g. BILSTEIN - B16 PSS10

RLE

<<I am considering +2 from 17 inch factory wheel. Is there any down side in terms of performance after the upgraded ? Hard to find a super light (18" ; less than 16lbs) and good looking wheels for the W204...>>

Less than 16lbs?

The 18" AMG factory wheels and tires on my car (C300 Luxury) weigh 54 lbs. Each. That is damned heavy and certainly contributes to the not-so-hot ride. They do look "sick" though, whatever that means. Right now I'm running my winter tires (Nokians) on the OE 17s and the ride is marginally more civilized.

Keep in mind that a really big wheel (with low aspect ratio tires) is going to have less resistance to chuckhole damage if it's lightweight than the overweight OE wheels. M3 owners know all about this.

When I switched to the 18s, I purchased Bridgestone RE050A tires which are great tires, wet or dry, but are a bit noisier than I expected. I see that these tires are factory stock on the '08 Infiniti G35 and the new M3.

Derspeed

Holy Crap! The split 5 spoke AMGs with tires weigh 54 lbs?

RLE

<<Holy Crap! The split 5 spoke AMGs with tires weigh 54 lbs?>>

So says my balance scale.

oblu

That's pretty normal for a cast aluminum wheel.

According to tirerack.com, the 225/40-18 Contisport3 is 21lbs by itself; the rear tire size as 255/35-18 are 24lbs.

So the wheel itself isn't terrible. But it's not light either. OEM cast wheels never are.

narky

18" at less than 16 lbs?

Wow.

I don't think a wheel like that would be very practical in a daily application. Could a wheel this light be strong enough to withstand the potholed streets?

milsons200

Volk Racing RE30 weight 16.5lbs from tire rack. I think it is a strong rim; 1 pc forged wheel.

narky

Well, of course, if you wanna spend the loot, I guess. I think I'm gonna wait until I get sick and tired of the AMG 18" to get new rims. I like the AMGs a lot, as of yet. We'll see how long it takes me to tire of them.

tanktube67

the bigger the wheel the slowest it gets and it takes longer to brake but you will not noticed.

abqhudson

Plus sizes are for looks and rougher ride. Stock 17s will give better performance than most (heavier) plus sizes, lighter than stock 17s will be even better. When was the last time you saw a race car running on tires with a skimpy sidewall?

narky

One possible performance benefit of larger wheels would be in the larger tire contact with the road. More rubber on the road equates to better handling performance.

But then, as many have already said, that increase in handling is probably negated/offset by the decrease in acceleration/deceleration/riding comfort/etc. Everything is a give-n-take!

In the end, do what makes you happy -- it's YOUR ride.

For the longest while, I've been adamant about not adding anything that does not add to the pure performance potential of any of my vehicles (2- or 4-wheeled). But now, I'm beginning to change a bit... I'll probably add a spoiler to my C300 even if it's just for show, because I think it just looks better. And it'll make me a little happier. In fact, with this car, just about everything I do to it will most likely be purely for cosmetic reasons. I have become that guy (All show, no go) that I used to laugh at...