Nicholi2007

I came across the following article as I want to upgrade to bigger tires.

There has been a recent upsurge of extremely low-profile tires and extraordinarily large-diameter wheels on all types of personal vehicles. Is this good: stiffer sidewalls less lateral movement? Or is this bad: more unsprung mass * changing suspension requirements? Or is this just an expensive affectation? -- Frank

RAY: It's primarily about style, Frank. People want bigger wheels because they look cooler.

TOM: And if you use a bigger wheel, you have to use a lower-profile (i.e., shorter sidewall) tire so the wheel/tire combination still fits in the car's wheel well.

RAY: The weight isn't much of an issue, because alloy wheels are pretty light. And when you go with a bigger wheel/smaller tire combination, it's pretty much a wash.

TOM: You do get some handling benefits with lower-profile tires. The less-expansive sidewall you have, the less the sidewall will flex on turns. That's good for handling.

RAY: But you pay a high price in ride quality. Because you have less sidewall, there's less of it to absorb bumps and potholes. So lower-profile tires give you a much harsher ride.

TOM: The other significant argument against low-profile tires is that with less sidewall, the wheels themselves are much more vulnerable to being bent from potholes and scraping up against curbs. Especially if you live in a city. And when you have to replace a 19-inch alloy rim and it costs you $750, you're going to wish you'd gotten the smaller wheels with bigger tires, even if you don't look quite as cool when you go to pick up your dry cleaning.

© 2007 by Tom and Ray Magliozzi and Doug Berman Distributed by King Features Syndicate, Inc.

I am leaning towards 18" up from 16". The suspension is stock although I'll likely go to a sport suspension. I'd like to hear from others who upgraded to a larger tire from stock.

AzCamel

the sport suspension is really nice, even with 234/25/19 and oem suspention it still rides smooth, but nothing bad IMO, compare to my brothers 09 Honda CRV my benz with 19s is still smoother.

paypaboi

when i went from my stock wheels to my 19's i changed the sport suspension out for KWv2's so I am not quite sure how the would have ridden on my sport suspension but they ride smooth on my KW's.

maverik259

im rolling on 19's with stock sport and they work just fine!

Sincity

Just bent 2 rims from hitting a pothole. Luckilly it wasn't that bad and the shop easilly straightened them.

TemjinX2

i went from 17's to 19's..with a 235/35/19 all around. The tires i bought have a slight lip around to to protect the rim from potholes. I drove over a couple of pot holes since i got them and no rim benting. As for ride quality, i didn't really notice a difference unless you drive on really bad roads. but you won't feel too big of a difference on any decently paved even highway.

pawe

One question. I think the 05 stock rims come with 225's right? Since I need to get new tires, can I use 235's so the gaps can be smaller?

TemjinX2

you can fill a little bit more of the gap by using tires with a larger sidewall. Given how high our mercedes are stock, you won't really see much of a differnce until you lower the car.

pawe

Im actually satisfied with the stock height for the rear but the front has this nasty gap and that's probably what I will do. Do you know how large of a sidewall i can go for the stocks without the front rubbing?

TemjinX2

whats your current tire size? you should really look at the wheels thread. they mention rim and tire sizes with pics. If you stay with a 225, you probably won't rub. I only rub on U turns with my 235's.

pawe

i got stocks on mine right now. I guess 235 is the largest i can go since you rub on 235s already. thanks!

TemjinX2

tire width won't effect your gap...it'll just change your contact patch size. Also keep in mind, you 235's for different brand tires are slightly different. I rub on 235's but then there some people that dont rub on 235's.

You should check out the wheel thread.

pawe

oh shoot, what a bonehead. 225 is the tire width..not the height. I Didn't even noticed that when i first posted my question.

What Im trying to do is get a higher tire to fill the gaps. same width but higher tire size than the stock. Ill just check the aftermarket wheel thread. Thanks man!

TemjinX2

you want a higher side wall size.

W203E35

Don't be fooled by these articles buddy. Keep it the way it is, don't go spending extra money for new tires. You just have to be extra careful not to scratch the rims and not to hit huge potholes so you dont bend them.

Also as mentioned above you get better performance

Also this is IMO = 18" you don't need to worry about anything. (although from 16 to 18 you will feel a difference but still a nice smooth ride just stiff)

W203E35

Agree to that my mom has a 07 Honda Accord and I feel every little bump, with my stock suspension the ride is stiff but at the same time pretty smooth. I don't feel every crack on the road like I do with the Accord.

JLD2k3

I bent 18's three times before getting 17's. One year on 18's - 3 bent rims. 2.5 years on 17's - 0 problems.

SickSpeedMonte

Stock is 225/45/17 up front on a 17X7.5 and 245/45/17 in the rear with a 17X8.5

As for the low profile tires handling better, it's really only true for a decently smooth surface. If you get any kinds of bumps, you'll want compliance just like you would in a suspension setup. It also becomes harder to feel the edge of the tire's performance capability. You may be able to pull a little bit more lateral acceleration, but there will be less warning before you lose traction on the tire.

The big practical reason for running bigger wheels is bigger brakes.

And the little lips around the bead of some tires is there to protect you from curb rash, although I would not rely on it by any means. They wont do squat for pothole protection. Potholes can bend rims without ever directly touching the wheel iteself.

Nicholi2007

The article as a general guide seems accurate. If your going to go with big tires, it makes sense that the surface needs to be relatively flat and smooth.

The roads in L.A. are a disgrace. Massachusetts went through a similar period because of too many tax cuts and bureaucratic inefficiency (they are now excellent). I am going to go +1 from stock.

Glyn M Ruck

I'm very critical of ride quality & it's no accident that Benz stopped at 17" with Sport Pack on these cars - It's the largest size that does a reasonable job of maintaining Merc ride comfort. It's also effected by tyre choice. Michelin will give you the most comfortable ride with low profile tyres because they have the most pliant sidewalls in the tyre industry.

I would never go lower than 40 profile under any circumstances. The V6s are a little more tolerant of lower profiles because of the extra weight.

I'm going 17 X 8.5 ET30 rear with 245/40 & 17 X 8 ET30 front with 235/45 from my standard 16" 225/50 - stock set up & suspension. SA stock is lower than US cars especially in the front.

This is all very personal but no one must tell me that 19" wheels with 30 or 35 profile tyres don't screw up the ride quality. They do - period - It depends what you are prepared to tolerate.

maverik259

im running 19x8 235/40 and 19x9.5 255/35 and no problems whatsoever...ive had them since november! hit many a pothole on accidnt and no problem, i also keep my tires nitrogen filled which will help slightly in rebounding from quick bumps by being more incompressible than air...just a thought

Glyn M Ruck

Nitrogen is a waste of time on road cars & frequently stops the tyres from running hot enough. Good for track as it keeps pressure more constant & you are running soft compounds that can overheat & blister.

W203E35

You bent 18"s 3 times? Man thats pretty insane bending 3 rims in one year. I don't think I can do that even if I tried.

I don't know about what kind of rims you had but I think if you get good rims (maybe forged) you will be good. What kind of rims did you have?

I mean the w204 sport (My rental (free of charge ) since my w203 is in the shop) has AMG 18" stock. That's a W204 C300 coming with 18" stock rims. I think if MB is putting those rims out factory then you don't have anything to worry about especially 18".

I think 18" are whatever but if you said 19" I would say maybe.

Not trying to be rude but what kind of rims did you have that bent 3 times in one year??

TemjinX2

yeah i have cheap chinese replica 19'' rims and i havent bent them at all.

Glyn M Ruck

Just remember the W204 has different spring & damper rates to the W203 and mechano-active dampers or fully active dampers depending on how it's speced.