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Discussion Starter #1
About to order a new set of tyres for a 350, but dont know whether the XL version is the best option or not. The more I try to research into this the more confusing it all becomes. Googling for the answers to this often shows up contradictory opinions on XL tyres being better or worse for handling and performance compared to the non XL versions. For example, some say the lack of compliance in XL rubber is not so good for cornering and handling while some say the extra rigidity does actually improve performance. Also, these opinions are never SLK specific and I can't find answers here either.


Am beginning to conclude that XL tyres would offer better performance, but only for cars a lot heavier than the SLK... But on the other hand I understand that SLKs are notorious for rear tyre wear, which now leaves me wondering that the XL version would offer better wear due to the harder rubber? But then again I read that XL tyres need to operate at higher than normal tyre pressures to remain safe - as the increased flexing due to a lower pressure would lead to a blow-out - which now leads me to wonder that an XL tyre with its correct higher pressure would only add to the rear tyre wear rate for an SLK along with the additional consequence of low grippiness due to the lack of tyre compliance... It really is confusing and the tyre manufacturer websites dont seem to offer any useful advice either.



Also, Michelin Pilot Sport 4 or Goodyear Eagle F1 Asymmetric 5?



Anyone tried both XL and normal versions of the same make of tyre?
 

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Super Moderator UK SLK 55 AMG 2007
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A lot depends on your use.

Hard acceleration, distance travelled, type of roads, weather (summer only or year round).

Our 350 and 55 are year round. Mixed roads.
Trips vary from local to touring.
M'way and single track.

We have ended up with PS4s on both.
We did try the harder Bridgestones, but wet and cold weather, harder acceleration
made them more likely to slip. Once they began to wear, wet performance got rapidly worse.

Winter tyres not an option for us.
Even when temp does hit a low enough figure, it does not stay there for the entire winter.

There are softer tyres, but that increases wear rate.
There are harder tyres, but at the cost of grip.

It's one of those questions that there cannot be a definitive answer for.

Roughly, for a commuter, not pushing the limits, probably fine.
For a commuter who likes to 'use' the car, probably not.

We all drive differently & require different things from our tyres.

And as you say, SLKs are not exactly a heavy car.

The above ignores the extra factors of wheel size & suspension set up amongst other things.
 

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Discussion Starter #3
Wheel size is 17" and suspension is the bog-standard. Driving is a mixture of speed-bump riddled town plodding and as much spirited driving as I can get away with on the twisty roads around here - so am leaning towards the idea that non XL versions with their increased compliance for grippiness and less likely to slip characteristics, as well as being a generally lighter tyre, is the more suitable option for the lightish SLK.



A lot depends on your use.

Hard acceleration, distance travelled, type of roads, weather (summer only or year round).

Our 350 and 55 are year round. Mixed roads.
Trips vary from local to touring.
M'way and single track.

We have ended up with PS4s on both.
We did try the harder Bridgestones, but wet and cold weather, harder acceleration
made them more likely to slip. Once they began to wear, wet performance got rapidly worse.

Winter tyres not an option for us.
Even when temp does hit a low enough figure, it does not stay there for the entire winter.

There are softer tyres, but that increases wear rate.
There are harder tyres, but at the cost of grip.

It's one of those questions that there cannot be a definitive answer for.

Roughly, for a commuter, not pushing the limits, probably fine.
For a commuter who likes to 'use' the car, probably not.

We all drive differently & require different things from our tyres.

And as you say, SLKs are not exactly a heavy car.

The above ignores the extra factors of wheel size & suspension set up amongst other things.
 

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Super Moderator UK SLK 55 AMG 2007
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25,406 Posts
Wheel size is 17" and suspension is the bog-standard. Driving is a mixture of speed-bump riddled town plodding and as much spirited driving as I can get away with on the twisty roads around here - so am leaning towards the idea that non XL versions with their increased compliance for grippiness and less likely to slip characteristics, as well as being a generally lighter tyre, is the more suitable option for the lightish SLK.
Sounds similar to us.
If year round driving as well I'd duck the XL myself.
But, as I say, it's a personal choice.
 

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Super Moderator CA 2012 SLK55 AMG w/P30
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Keep in mind that "grippiness" will only last 2 mo or less.

Especially with a stick, you'll be putting a lot of stress on that rubber. You will notice that after 6 weeks or so, cornering is still great but straight away acceleration well, you'll notice the difference between new and 6 weeks :wink:.

My "new" rubber when I got the car (conti's) lasted 3 summers (maybe 6,000 mi total). Put PS4's on in May '19 and about early July, cornering at well above posted suggested speed for a curve was still bang on but on jack rabbit starts, well lets just say they slipped a LOT sooner than when brand new. AND I do have the P30 option. Nice to get the spin AND no fish-tailing :grin:

They slipped when new on dry pavement (again to be expected with a '55) but more so a short time later (which was also expected). Just don't be disappointed in any top-level tire you do get as to performance.

Your power with a 350 stick is marginally less than a 55 so be warned.

My experience anyways. Just sayin' :wink:
 

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Discussion Starter #6
Thanks for the advice and suggestions - it has to be either Michelin Pilot 4 or Eagle F1 Asymmetric 5. So I'm going for the non XL Eagles as I'm now more convinced that an XL tyre probably won't deliver any extra benefit for an SLK, and it seems that the Pilot 4 is only available as an XL. If of interest to anyone a set of four Eagle F1 A.5s [225 45 r17 & 245 40 r17] can be had for a surprisingly low £309 from Giga Tyres, so I'm snapping them up now.
 

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Wise choice...you're running regular suspension and steering on 17's...enjoy the ride

Sent from my SM-T550 using Tapatalk
 
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