City Rat

Its coming up on time to get new tires. You all know how this story goes, famous last words..."while they're in there we might as well..." In fairness I need new brake shoes, shocks and wheel bearings. So as I think this through it seems like as good a time as any to make a switch up to 18 inch wheels from the stock 17s. My goal is to have wider tires, better contact patches and in the end gain better traction and handling than stock in highway,mountain driving.

First question - Am I on the right track? Will traction and handling gains be noticeable with 18s over 17s?

Second issue - Getting the tire sizes right.
Stock front 225/45/R17
stock rear 245/40/R17

Tire rack tire calculator suggests the following setup for 18s on my stock ride height car
Front 225/40/18
Rear 255/35/18

Will I notice a marked upgrade in traction and handling with the above setup on 18s?

Currently looking at:
Continental Extreme Contact DWS
http://www.tirerack.com/tires/tires....t&autoModClar=

and the

Michelin Pilot Sport A/S 3
http://www.tirerack.com/tires/tires....t&autoModClar=

Love to have recommendations from those who have run them.

Third issue: Wheels
Eventually I'd like to get 18 inch SL AMG wheels but until I can find a set that I like for the right price I am seriously considering a wheel tire package from tire rack.

Question- Does anyone have any experience with either of these wheels or either company? I think that on my black over silver cab they might look interesting and be a change of pace for a while. That said no sense in buying them if they are gonna fold up like candy wrappers at the first pothole. Also is the offset right these wheels for my stock setup not looking to run spacers or big brakes. Thanks.

http://www.tirerack.com/wheels/Wheel...kageFlow=false

http://www.tirerack.com/wheels/Wheel...kageFlow=false

///AchMeinGott

My personal opinion, if you're looking at tires specifically advertised as snow worthy, you're not yet serious about improving traction/handling. I'm sure I'll get flack for that, but fact is, changing tires is one of the biggest single improvements you can make. Pilot Sport A/S and DWS are great tires... for what they are. So you gotta decide if you're ready to step up to some serious tires first. I drove summer tires on my last Vette year round, rain, snow, or shine. Hairy in the snow, but far from impossible. Orrr keep 17's for the winter, and nice, fancy 18's with sticky tires.

My second suggestion is don't go up a size in the rear and not front. However minimal, it increases understeer. Bigger fronts bite in and turn. 255 rear is fine, but go 235 front.

Also, your links are dead BTW.

insame1

I agree with ///AchMeinGott. There are a few other things you should consider also. The weight of the wheel will have an effect on the car too. More or less unsprung weight will change the handling characteristics. The other major factor would be comfort. Going to a shorter side wall will reduce tire rollover but will also make the ride more stiff as you are giving up some cushioning the tire provides. There is also a point where the smaller side wall could negatively effect your handling. Not enough side wall and tire rollover and reduce your handling capabilities.

City Rat

Fresh links:
Continentals:
http://www.continentaltire.com/produ...hicle_id=22062

Michelins:
http://www.tirerack.com/tires/tires....et&autoModClar=

AchMeinGott, very interesting idea about throwing snow tires on my stock rims. I like rotating tires, keeping things in use and in the end extending the life of everything. If I was going to head down this road what would be "serious tires" for handling, wet and dry in your view?

Wheels:
OZ Italia 150
http://www.ozracing.com/car_wheels_v...50/558475.aspx
Wheel description from Tire rack:


"Front and Rear"

• Size:
  18x8
• Offset:
  35mm
• Backspacing:
  5.91"
• Bolt Pattern:
  5-112
• Rec. Tire Size:
  225/40-18
• Weight:
  25.0 lbs.
• Finish:
  Black Painted
• Construction:
  1pc. Low Pressure Cast
• Finish Warranty:
  1 Year

Advanti FS Fastoso
http://advantiwheel.com/current-whee...fastoso-black/
Wheel description from Tire rack:


"Front and Rear"

• Size:
  18x8
• Offset:
  35mm
• Backspacing:
  5.91"
• Bolt Pattern:
  5-112
• Rec. Tire Size:
  225/40-18
• Weight:
  25.0 lbs.
• Finish:
  Black w/Machined Undercut
• Construction:
  1pc. Gravity Cast
• Finish Warranty:
  1 Year

Next,
Thanks for the responses thus far. I am truly agnostic here on the tire size and am here looking for advice. Really the collective judgement of owners of my same vehicle, who have run either of these tires and can tell me the optimal sizing front and rear, so that I can get the best handling and traction without rubbing on my stock height car, stop to stop turning assuming fully loaded and compressed springs. (none of this it only rubs when someone sits in the back).

I will also confess a duh moment as when I first ran the tire calculator I did not notice that you got results in three fields, stock, recommended tire sizes for either 18 or 19 inch wheels OR you can indicate custom sizing. Clearly I'll fall into the third category with your collective assistance.

Sidewall height- funny that you mentioned that. I have never been a fan of rubber band tires and well understand how the loss of sidewall area will reduce side wall flex and give a stiffer ride and reduced handling but I was not sure how much difference 5mm would make from 40mm stock rear height to 35. Thanks for fleshing that out. I am happy again to go with whatever folks have found is the sidewall height that works the best for handling and traction given the other parameters, i.e. 18 inch wheel, stock height vehicle, unrolled fenders and not ever on a track.

Tire width- Again If in the collective experience of owners of this vehicle a front tire width of 235 or 240 is optimal for handling, traction without rubbing on 18s thats what I'll go with. If the collective thinking and experience is that 255, 265, 275 in the rear is the best width in the rear for handling, traction without rubbing then that's what I'll go with. Also to add a post script on this point , I was talking to some of my former beemer brothers and they seem to be running 245/40 18 fronts and 265/40 18s rear. I get very different cars and suspension setups. That said would that setup give me better traction, handling without rubbing front or back on my stock height 55? Thoughts very much appreciated.

Again all advice is greatly appreciated.

sick430

Wheels seem a little heavy, this is something you will feel performance wise especially as you go up a size.

City Rat

Interesting. I never asked but I'm sure some of you guys here know, by way of comparison, how much do the stock AMG 17 inch wheels weigh each?

///AchMeinGott

*Full disclaimer*
I don't own a CLK. Actually, I own nothing fun at the moment, but 2 of the 3 cars I'm considering and thoroughly researched are 05/06 CLK55/C55. The 3rd is an 05/06 GTO, all of which are undertired, make a ton of torque, and take entirely too much research and planning to fit bigger wheels/rubber. So take what I say with a grain of salt.

First, the 2nd number isn't mm, as many think and you seem to suggest "I was not sure how much difference 5mm would make from 40mm stock rear height to 35," so one 40 series tire isn't the same as another. It's "aspect ratio" which is the percent the tire is wide, tall. 245/40 means the sidewall is 40% x 245mm = 98.4mm tall. A 255/35 means 35% x 255mm = 89.25mm. A 255/40 though, would be 102mm, different from stock despite being a 40 series tire.

So... 18x8 easily fit a 245 tire, but I understand just how little clearance there is up front. 225/45/17 is a 25" tall tire. Unless you want to do some in-depth research with finding a perfect offset wheel and run a 245 tire, I would suggest a 235/40/18 on an 18x8 rim. That's a 25.4" tall tire, less then half an inch difference will keep all the electronics happy(minimal impact being front tires anyway).

Rear 245/40/17 is 24.7" tall. 255/35/18 is 25" tall. Well under half an inch plus, front will sit .2" higher and rear will .15" higher keeping things fairly even. 265/30/18 is 24.3" so that's an option too, albeit then the front will grow while the rear will shrink overall. But, a 265/30 will need a 9" wide wheel to fit right. 255/35 should be an 8.5" wheel, but you can get away with it on an 8" wheel.

Not all tire companies make a tire the exact same size though. Measuring is vary loose, and there are fat 255's that are wider the skinny 265's. Usually that trend is brand-wide. I remember from the Vette forums guys with 345 Nitto Invos sitting next to almost identical 325 Michelin PS2's. So my suggestion would be to find a fat 235/40 and 255/35 tire set. How extreme of traction is up to you. The stickiness range is huge. You could go from Continental DW, to Michelin PSS, to Nitto NT01's depending on how much traction you want, how much you worry about driving in the rain, and how much you are willing to spend(and if one brand has matching f/r tire sizes).

tw2

As pointed out, reducing the weight is important. The stock wheels 17 or 18 are not light but you can easily get heavier, most show orientated wheels are very heavy and poorly performing. Definitely look at some light weight rotary spun wheels. I like the TSW nurburgrings but you guys have heaps of options in the US. Of course good lightweight wheels are not cheap.

City Rat

First, thanks for the responses and pms. I am settling on the following setup:

Front 235/40-18
Rear 265/40- 18
Note on Rear 265/35-18 will work as well, Chappy has run this set up for several years and still like it.

My question is both sets of wheels that I am considering are 18x8. Will I be able to comfortably run 265 in the rear on 18x8 wheels or will I need to look for either an 18/8.5 or 9?

BTW in terms of the rest of the setup I'm going with Bilstein B6s all around and, if I can get a decent price from Gert, I'm going with the AMG Euro spec spring package for a very mild lowering. I need new shocks and I picked the B6s as they can go with the stock springs or the euro spec springs, if I can get the spring and pad package for a decent price. Got an email out to Gert, awaiting a response.

Again looking forward to your responses and thanks again in advance.

tw2

9" would be minimum for the 265 in my opinion anyway. The stock 255 is on a 8.5" rim which is about the limit.

///AchMeinGott

I would absolutely run a 265/35/18. 265/40/18 is 1.6" taller then a 245/40/17. It may or may not mess up your stability/traction control, but either way that sidewall is a good bit taller then stock, and will be more "mushy." It should make the ride a bit more forgiving, but will negatively impact handling if that's your objective. However minimal, it'll also make your gearing slower.

Be it 265/35 or 265/40, that's an 8.5" wheel at minimum. Otherwise you'll be looking at a good bit of bulge. 9" would be ideal though.

City Rat

Thanks very much for the input. I learn something every time I login to this forum. Last question, my preference is to run the same size wheels on all four corners. The wheel calculators for a couple of wheel sites are giving me a 18x8.5 in the front and 18x9 in the rear. Are folks here running wheel setups like that? Again my preference is to run 18x9s all around. Again looking forward to reading your thoughts. Thanks.

mguerrero

you can't run 9's in the front - not without some sort of spacers at least

tw2

I would definitely suggest sticking with the staggered setup. 8" front 9" rear. There is no performance advantage to 9" all the way around, not a good idea.

Also there is an ideal range of tire sizes which fit certain width rims. 265 might be a good choice for a 9" rim. 235 will probably fit on a 9" rim but it is not a good fit.

Traction is a result of the best quality tire for your driving in the right size on the right rim. Add in rim weight when talking about handling also. Wide is not better. Your contact patch changes shape not size. For forwards traction an LSD is a good thing to look at if you haven't already.

Chappy

I can recommend the Michelin Pilot Super sport tires as well.

City Rat

Thanks again for all the input. Very much appreciated. Wow very few places and very limited selection for staggered wheel fitment. I thought that I just was fumbling working the features of different wheel/tire sites until I spoke to a sales guy at tire rack who confirmed it. Seems like TSW is the only wheel company who really has some selection for staggered fitment. There has already been a vote for one of their models the aptly named Nurburing. Anyone else have experience with the quality of their wheels? I have only seen 1 negative review from a guy who had been circuit racing on a set for a season, not anything I will be doing. Seems a lot of Porsche and BMW guys are running their wheels. Thanks.

insame1

There are other options than tire rack. It really depends on your budget. The best setup I have had was the Renntech Monolite wheels with Bridgestone ps-04 tires.

Quant

iTrader: (1)

Is this for 208 amg? I have set of 18 sl amg wheels that I used on my car that I can sell you with appropriate bolts.
In term of tires, highly recommend the pss (car loves them). The dws and Bridgestone pole are really good as well. Best tire size I found for comfort and handling was 235/40 and 265/35.

City Rat

Thanks for the feedback and agreed. That is how I got around to the TSW line of staggered wheel packages. The decision on which wheels to go with also depends on what are you plans for the car and how much longer you plan on keeping it. While I have no current plans on selling the car in the near future given its age/ mileage a potential sale is always somewhere in the calculus, even if way in the back of my mind. Therefore I plan for the car to be well maintained and in good running form for my safety and driving enjoyment for as long as I drive it. Altogether this shakes out to making a moderate investment in wheels that are sized properly to play their role in better handling during "spirited" highway driving.

City Rat

Great can you PM me with current pics that show the condition of the wheels, some data on the wheel sizes and what kind of driving you have been doing on them, e.g. track car, daily driver or a weekend warrior that does some of both. Thanks. I get up to the city fairly often so this could be doable. Thanks.

Quant

iTrader: (1)

Wheels got to experience around 6 days of fun around track. will pm soon

CLK55Ian

If you have other cars to drive in wet and especially cold weather, I highly recommend Michelin pilot super sports, they have transformed the performance of my car. Fantastic tire on the 208, I'm still on the stock 17's but not for much longer. Recently scored a set of 18 inch SL55 5 spoke wheels for a steal. Will likely be putting PSS on those wheels as well.

insame1

Sorry for the slight thread jack but has anyone suggesting the Michelin pilot super sports ever run the ps-04 Bridgestones. I have run both and for the money I would take the ps-04s all day. Not trying to say anything bad about the PSS's just wondering what other people think.

http://blog.tirerack.com/blog/make-d...ot-super-sport

City Rat

Thanks and I take your point. Two points, first, as is apparent from the discussion in this thread tire choice is inevitably a compromise between the desire for maximum traction, handling and road noise gas mileage all taking into account driving style, driving conditions and the application for the vehicle, DD, track, weekend warrior, etc. For me , at this point and thanks to the input from folks here and my own research, I'm skewing towards a tire that can give me traction and handling benefits under various weather conditions. Not because I want to flog the car but because I like options and for everything that I own to have maximum utility.

Second, while yes, I have other cars to drive, I am honsetly not a fan of letting these cars sit. Just not a believer in garage or trailer queens. Obviously if I am headed off on a trip, the car will sit in the airport parking lot, etc for a couple of weeks, no worries. However, the sense that I get, since joining this site and reading endlessly about the problems people have had is that a number of the more common tire problems, electrical problems, leaks etc. can be traced to garaging these cars for the months encompassing late fall and winter and not taking the wraps off until its sun shiny summer again. Not that you were suggesting that exactly. The Germans built these cars to handle the weather they have there and so I have driven the car in the snow, rain and icy slush. While I don't treat the 55 like my heavily modded Landcruiser, I expect that she is prepared to go in whatever weather if needed. While a bit off topic, she has handled decently in those crappy weather conditions when she was needed, which is all that I would expect. Thanks again. Your thought is much appreciated.

CLK55Ian

Ok buddy