James L.

I still dont quite understand the fact that CL65 being a heavier/larger coupe, it wears a smaller tire then the much smaller SL65? It just doesn't make sense.

If I'm not wrong CL65 is equip with 245 front and 275 rear wheares SL65 is equip with 255 front and 285 rear. how can a smaller can accomodate 10mm and not a bigger car?

In the beginning I would expect perhaps 300mm from the rear of the CL beast! That would definately help a lot in it's traction!

Also if I am to go out and change the orginal 65's rim to an aftermarket one, would I be able to fit a 295 or 300mm tyres on that car?

Schiznick

You are correct on the SL65 tires sizes, just looked. A agree it is strange the CL has smaller series tires than the SL.

Sent you a PM.

James L.

I remembered it was discuss somewhere in this forum before.

Someone said 275 was the maximum that CL could accomodate? Anyone could verify this?

thearle

I have both the CL65 and SL65. Though the CL has a 10mm smaller tire track, the CL65 has larger tires.

CL65: 245/40-19 (OD: 26.71-in) and 275/35-19 (OD: 26.57-in)
SL65: 255/35-19 (OD: 26.02-in) and 285/30-19 (OD:25.73-in)

I had switched to Michelin PS2's on my SL65 in order to get a closer OD with the front, using 255/35-19 and 295/30-19 (OD:25.96-in).

The OE Bridgestones don't grip well enough with that much torque.

AMG2GO

Well there is more to consider than dry traction. larger tires have the following problems:

1) more weight. This is unsprung weight and affect the cars performance in braking, accelerating, and handling. This is huge.

2) More rolling resistance. The larger the contact patch, the more natural rolling resistance. This is worse for performance and gas milage.

3) more noise and harshness. larger tires transfer more vibration, and are also noisier. It all comes into the cabin.

4) tracking. larger tires do not track as well generally and tend to follow imprefections and grooves in the road.

5) worse wet weather traction. On anything but a dry road, traction gets worse as the contact patch grows. There is more hydroplaning in the rain, and because of more even weight distribution much worse traction in the snow.

So the engineer that designs the suspension, has to keep all this in mind. Bigger tires may look cool, but once you go over a certain size you start to negatively impact the car. Cars that people put 20" wheels and tires on, are generally bad for the car as it was never engineered into the overall suspension.

Manufacturers are now bowing to pressure and installing larger wheel/tire combinations on a lot of cars. This has more to do with marketing and less to do with performance. Most road racers do not use combinations this large.

The fact that AMG sees fit to install a 19" rim with no bigger than a 275 section tire on the rear its most performance oriented vehicle just validates these points.

I doubt that it has anything to do with what will actually "fit". Because believe me, bigger can fit.

If you want better performance, it is best to change the compound, and keep the size the same. The smallest changes in size introduce more understeer or oversteer and throw off the balance of the car in terms of handling, and braking (even the brake force distribution is designed with tire charactersitics in mind). This is a balance that the engineers worked hard to achieve. Switching to a softer compound will give significantly better performance without these negative effects, at the cost of faster tire wear.

carlosfernandez

Wow, that's a lot of info. thank's.

James L.

AMG2Go if you were referring to a normal car with puny performance figures and power ratings, I would entirely agree with you.

But sadly for a CL65 with 612hp and 1000nm (restricted) I will only agree with you on point number 5 where larger contact patch makes it much more slippery on wet conditions.

With so much power, I seriously doubt the car will be bothered by unsprung weight of the tire. Whats important is absolute traction. Look at supercars, they all have over 300mm profiles compared to maximum of AMG's 285mm on SL55/SL65. As for imperfections, once again, supercars have such wide tire, why not AMG?

Well with no LSD or similiar traction control mechanism, I just think AMG should be wider tires! Was it because limited by the CL's suspension and wheelarch's tolerance?

It makes no sense, why not put a LSD! They do WONDERS!

No offense AMG2Go, just thought of sharing my own opinions.

AMG2GO

JLLK the 65 does have an LSD.

I am trying to just shed some light on the drawbacks of wide tires... and to point out that it is all an engineered system... tires are a component of the suspension. I strongly advise against making any significant changes to a car whose engineers designed the suspension for that tire. You may make a small gain in one category, but it will come at a loss in another category. Generally, because of a lack of engineering, the losses will outweigh the gain.
All these guys that switch to bigger tires... I can guarantee you on a track, their gains will be very dissapointing... they may not even be a gain but a loss. These "upgrades" are usually just more cosmetic than anything else.

I know because I have done a lot of track racing and I have seen first hand a lot of racers experiment with various wheel and tire combinations. Many times bigger combinations actually slow down the overall track times. Furthermore big is not always as necessary to go fast as is balance, almost any Lotus perfectly demonstrates this.

The 65 may have a lot of power, but that still does not make it immune to any of the points I made. If you just take a 65 and slap on wider tires, you will make a small gain in dry traction. But run it around a track, and your times may actually slow down. It will start to understeer or oversteer more, and your braking distances may not improve at all. The brake force has to be carefully distributed with the knowledge of what the weight shift is during hard braking, and what the front/rear bias needs to be. So making your own changes is not a good idea.

Now I am not saying a fat tire can't be engineered into the 65 and make actual performance gains. But the purpose of the car determines this. A Dodge Viper has some serious tires... but its interior noise level is not exactly the same as a CL class Mercedes. The 65 is still an everyday car. Wet weather traction is important... ride quality is important... vibration is important... even the size of the spare tire that has to replace the fat tire is important. AMG engineers have a lot on their plate there. Wider tires can fit on a CL. What they have on there is the best overall compromise.

If you really want to make performance gains, on a more serious level than what an extra 15mm of width will get you, my advice is to switch compounds. You can stick with the same size, get a soft compound road race tire, and have much better results. Of course MB won't do this, because the tire needs to last more than 2500 miles.

In the next generations of CL's we will see even more power and more torque. But I don't think you will see some super wide tires on there. Most likely the solutions will come by some other sort of mechanical and electronic wizardry.

Personally I hope the technology reduces weight instead, which will give better performance with less power, less tire, and less damage to the environment.

James L.

AMG2Go, it is all very well said. I will have to agree with some of your points after you rephrase them.

I suppose you're right, if slapping on wider tires will solve everything, I guess AMG engineers will have done that long time ago. lol

Btw, I heard only the SL65 has LSD but NOT the CL65 or S65. I am pretty sure about this. Please check on it. I think i've read it somewhere on this forum as well. Do a search on it.

It got me quite annoyed that they can fit one on SL but not the CL, which speaks of the much better acceleration and quarter mile times of the SL as well.

I am getting a CL end of this month. Around 10 days to go! Darn excited I can't wait!

It comes lowered around 0.75inch by AMG and delimited to 300km/h(187miles/h)

Just thought of sharing.

Schiznick

The CL does not have LSD.

s4avantgarde

you can fit a 305/25/20 on the rear of both the CL and SL...depending on various tire manufacturers

carlosfernandez

Really, I want to see a car with tire like that.

s4avantgarde

the wheel supply in walnut, ca has just fitted some 20x11 wheels on the rear of each of those cars m(CL,SL) with that tire size

James L.

Do they look ridiculous or over the extreme in those size and width?

Otherwise there goes my question again, why can't AMG put those on? They might help in certain amount of tractions!

I still think 612hp and 1000nm with an extra few kilos on the tyres and rims wouldn't hurt the performance figures. But with the benefit of those dry tractions, WOW. This is the case of CL65 vs CL600. People say CL65 not much faster then CL600 which is TRUE but from 100miles/h onwards to 155milse/h, CL65 will be much faster because at that speed there is no longer traction problems as compared to when you are starting to accelerate from 0. I can practically see ESP light permanently on in the first gear of the 65. Now when traction is much better for the CL65 would anyone still dare to say CL65 can't pull away from CL600?

Well, I might be very wrong bearing in mind of AMG2GO's certain points mentioned earlier. Well up for intepretations

AMG2GO

305/25 is a rubber band wrapped around metal. Should do wonders for the noise and ride quality of a $180,000 car. And what happens to the fronts that are now way out of balance with the rears? No offense, but does anyone really think the guys at "wheel supply" know something that the engineers at Mercedes and AMG do not? Do it if you want to look cool, but it ain't helping the car any.

I am not trying to be negative guys... I am all about mods and speed. I raced for many years. I am just trying to share my experiences. If you do mods, they should be mild.... mild mods may make you some small gains. Larger mods will start to throw everything off. It can be suspension, engine, brakes, whatever. You lose the engineered balance.

JLLK, you are getting a CL65... I am just saying be careful. Know that the engineering capabilities and resources of AMG under the MB umbrella vastly exceeds aftermarket tuners. Nevermind some wheel shop in Walnut. Be careful of what someone does to your car. A 65, as far as I am concerned, is an engineering masterpiece. I wouldn't mess with it all. If you do, make it mild.

James L.

Darn, you said it where it hurts... I guess you're entirely right. It make no sense at all assuming AMG engineers not knowing of the above mentioned..

Sigh, I guess that dampens everything.. guess I'll just stick with the original 19inches. Well was thinking of all the issues people talking about in Mbworld and how ridiculously lack of traction the CL65 is.. was thinking a wider rubber might help.. oh well.

I'll go with mild modifications. Might get the Kleeman ECU upgrades for the 739hp and 1300nm though. It is available at my region. Still contemplating what it'll do to the transmission and the traction issue will be even more of a joke i suppose.

AMG2GO

If you drive the car only on dry roads in good weather, which I am assuming you have a lot of where you are, you can look into some soft compound tires for the car. Take off the stock, throw those on, and you will see a world of difference without negatively affecting the car. I would consider the Kleemann LSD, if this car does not have one. Those would be my mods. The ECU.... its up to you... but I know I would not want to buy a used CL600 or CL65 with any sort of mod.

By the way if you call Kleemann (or Brabus, or Renntech, I am not trying to pick on Kleemann), they will all tell you how reliable their stuff is. And all the "precautions" they take. I have heard it all before. They are there to sell you their product... just remember that. They will tell you what you want to hear. If the engine could talk, it would have something different to say.

James L.

LOL how true how true!

As for regarding the soft compound, I have not much idea what tires exactly you're talking about. Are you talking about semi slicks? All I know about is some Advan soft compounds.

If only I could find slicks on 19 inch! lol

AMG2GO

Yeah I am talking about a DOT approved race tire. Like the Yokohama Advan A048. That is a killer tire. On an 18" wheel it will outperform any 19" combination. It is harder to find 19" competition tires... but they are probably out there. Worse comes to worse you get a nice set of 18" wheels (like on a CL55) and put some tires like this on there, the car will stick to the road like its been crazy glued. As a racer, seeing that on a car I am about to race would worry me a lot more than some guy with a 305 section tire that just doesn't belong. I am willing to bet that through the 1/4, if you do nothing else... a 305 will slow you down 2 tenths... and the race tire will speed you up 3 tenths. Thats just straight line... the difference will be much more on a road race track.

Even all that torque will have a hard time spinning this tire, believe me. Your car will hook up to the ground and take off like a bat out of hell. This sort of tire works wonders not just for acceleration, but also handling. I mean its a race tire.... very very different from road tires. Your lateral acceleration will improve more with just this sort of tire than it will with $6G worth of suspension mods. Your braking distances will be reduced by an enormous amount.

Its like asking Carl Lewis to run in boots then giving him some kick *** running shoes. Its that dramatic of a difference.

Of course its slightly illegal at least in this country... because if it rains, you are going to be all over the road. But I have ran race tires on the street before and no cop has ever known the difference. If you are concerned about traction, this is the route to go.

AMG2GO

By the way I am not condoning racing, changing factory tires, or any of this stuff.... last thing I want is someone injuring themselves. I am just giving out info... that is all...

I think both Yokohama and Kumho make competition tires that fit the CL. But they are 18's.

Even without going to competition tires, some road tires have softer compounds and provide better grip. You can give up wet weather traction and durability for better dry traction.

If you decide to change your regular road tires to something wider, don't go nuts. You can get the LSD. I am assuming if the CL65 does not have LSD and the SL does, it is more for noise/vibration issues. The SL is a harsher car. I don't think they were trying to save money on the CL.

s4avantgarde

I was just mentioning that size has been fitted to those particular cars...of course you sacrifice road noise and ride comfort when you upgrade tire/wheels sizes..Those are just the extreme sizes which those vehicles can fit. To each their won i guess...

Everybody can tell anybody their opinions, but in the end its the owner of the car that gets to choose what he/she wants right?

If somebodywants to put 24 inch, cubic zirconia encrusted chrome wheels on their SL, then let them...

carlosfernandez

I agree.

gobiz

WOW, Jllk, you live in Malaysia? I live in KL too. Such as amazing thing that you're getting a CL65 and even contemplating getting the Kleemann upgrades.

Massive respect to you. Car prices in Malaysia are extremely exorbitant and you must be very wealthy indeed. And you're getting the exact car I've been fantasizing about - CL65 with Kleemann upgrade. You're living my dream.

I'm leaving for the UK later this year, and hope to purchase an E55 over there where prices are much much more reasonable. But probably will have to sell it again when I come back in 4 years time as if I bring it back, I will of course be taxed 300%. Congratulations on your purchase and again, my fullest respect to you.

James L.

AMG2GO

Its just seems rather odd that CL65 does not come with an LSD. I really don't think AMG engineers don't put in that thing purely because of road noise/harsher rides? And most definately I will not believe/tolerate them not putting in an LSD on a $185,000 car to save some cost. They did not even mention having an option of LSD on their cars. So I am sure it has to do with engineering issues thats rather quite serious. Benefits of LSD are huge and not putting one on, must have some ill effects that they know and we don't.

I've heard about 19in slicks before but they just sound ridiculous. As far as I know, Advan compound does have one of the best tractions and sadly they go up to 18inches like you mentioned only. And I won't change the gunmental OEM rims man! They look just too awesome and nice to be changed. I might as well start looking around for something rare.. 19 inches full slicks. lol

Btw, IMHO I think Kumho tires are 2nd rated. They are not that good. I used to drive their normal compound version couple years back. The ride, quality, tractions all just seems so budget label to me... My opinions only. Pls don't start flaming me heh.

Don't worry about the racing/modifying, I'm old enough to know what I'm doing. Modifying too much of this CL65 will take the sexy appeals away from it.

James L.

Hey Gobiz!

Nice to see another fellow Malaysians on board! I've known around 3 or 4 so far. Its really hard to find fellow Merc fanacs from our corner of the world. Most of the boys fanacs about either EVOs or WRXS. lol

I am from Sarawak btw. The so called east Malaysia where people still lives up on top of the trees? lol. I am indeed thinking of the Kleeman upgrades. I live near the Sultanate of Brunei area and that country is just 1 1/2 hour drives from where I stay. In brunei, there is a Kleeman authourised installer. I just emailed Kleeman heaquarter to verfiy their authenticity and seems that its true. The sultanate has too many exotic cars for Kleeman not to participate in it I suppose lol.

Nah man, I'm alright, just a person getting by. Ordering the CL65 has taken long. I requested import and deposited RM250,000 last November till now. Was told that it will arrive mid of April. Some delays as it is still in AMG factory. Had special options of removing the 250km/h limitter and drop the car by 1inch electronically. No need to mess with screws or use lowring modules. Heh heh.

Damn UK cars are cheap, if only I was born there and have a business there lol. You're moving their for tertiary studies i suppose? Rich kid :P