Tire size difference in CLK 350
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Newbie
Joined: Jan 2015
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2009 CLK 350
Tire size difference in CLK 350
Hello everyone,
I'm needing help with a tire selection on my car. I know the rear is calling for 245/40-17 but I am getting a good deal on some Serenity 245/45-17. Will this hurt the car at all to make this minor change? Thank you for your help and time.
I'm needing help with a tire selection on my car. I know the rear is calling for 245/40-17 but I am getting a good deal on some Serenity 245/45-17. Will this hurt the car at all to make this minor change? Thank you for your help and time.
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CLK55 W209, CL63 W216
That's quite a hefty difference. Most people would recommend a max of 3% difference from stock. You're talking about a 1 inch diameter difference as stated before. I personally would not run the tires. It may mess with traction control etc etc.
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Joined: Jun 2008
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From: Atlanta Metro
2008 clk550 - Navigator - Frontier
There is a reason you lower the profile height of your tires when you upsize your wheels. I am sure you will alter the driving dynamics of the car; whether good, bad, or near neutral is anybody's guess. You generally try to keep the diameter of the wheel/tire combination the same.
I think it would work ok; but it is not something I would do.
I think it would work ok; but it is not something I would do.
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Super Member
Joined: Mar 2010
Posts: 684
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From: Lebanon
2007 BMW 550i
Agreed, not recommended. The whole setup of the rear suspension is made for a tire at a specific dimension. By increasing the wheel diameter your stressing parts in the back by moving the pressure points along the rear suspensions parts. Its also going to cause weird things with your ESP and ABS for sure.
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2008 CLK550 Cab
Agreed, not recommended. The whole setup of the rear suspension is made for a tire at a specific dimension. By increasing the wheel diameter your stressing parts in the back by moving the pressure points along the rear suspensions parts. Its also going to cause weird things with your ESP and ABS for sure.
Although I personally would not put on a different size tire just to save a few bucks, can you explain or verify any of what you said? I think you are just making things up to make our cars sound like more precision instruments than they are. A tire changes diameter at least half that much just by tread wear. And I'm sure all the people who change wheel sizes from 17" to 19" do not always maintain exactly the same diameter. How does that change "pressure" points "along" the parts or stress them?
Super Member
Joined: Mar 2010
Posts: 684
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From: Lebanon
2007 BMW 550i
Although I personally would not put on a different size tire just to save a few bucks, can you explain or verify any of what you said? I think you are just making things up to make our cars sound like more precision instruments than they are. A tire changes diameter at least half that much just by tread wear. And I'm sure all the people who change wheel sizes from 17" to 19" do not always maintain exactly the same diameter. How does that change "pressure" points "along" the parts or stress them?
MBWorld Fanatic!
Joined: Oct 2012
Posts: 1,401
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CLK55 W209, CL63 W216
Although I personally would not put on a different size tire just to save a few bucks, can you explain or verify any of what you said? I think you are just making things up to make our cars sound like more precision instruments than they are. A tire changes diameter at least half that much just by tread wear. And I'm sure all the people who change wheel sizes from 17" to 19" do not always maintain exactly the same diameter. How does that change "pressure" points "along" the parts or stress them?
Everything in the suspension and ESP/ABS is affected by the wheels. Sure, you might make a case that your modded suspension lasted you X miles but nobody knows how long it would've lasted stock. Probably a lot more than X miles. There are plenty of articles on this you can Google yourself.
Anyway, I think the main issue I would worry about is ESP/ABS. They're tied to tire diameter. What makes you think the software some guy wrote based on some very specific parameters will work if you make the wheels 4% larger? I bet if you did some testing there would be issues.
Anyway, it's not something I would risk on my own car. As a rule of thumb (in addition to the 3% max difference rule), I would not skimp on brakes and tires. That's just asking for trouble.
Junior Member
Joined: Mar 2015
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From: Philadelphia
Mercedes-Benz CLK320 W209
45 in the rear has been great so far
I've been running 245/45 R17 rear tires on my CLK for awhile now. No issues what-so-ever with ESP/BAS, even my cruise control works perfectly. 
I bought my car with 16" wheels that were: Rear 225/45/R16 and Front 205/50/R16. My current wheels are wider and larger circumference.
I'm also not an expert.. I asked the knowledgable person I purchased my wheels from if 245/45 would be an issue, due to huge pot holes in the NE and they told me they'd fit and clear the rear suspension easily. I was warned not to go 225/50 in the front though, as it leaves very little room for clearing the struts. So far they are perfect and have driven a few thousand miles with no issues.
I bought my car with 16" wheels that were: Rear 225/45/R16 and Front 205/50/R16. My current wheels are wider and larger circumference.
I'm also not an expert.. I asked the knowledgable person I purchased my wheels from if 245/45 would be an issue, due to huge pot holes in the NE and they told me they'd fit and clear the rear suspension easily. I was warned not to go 225/50 in the front though, as it leaves very little room for clearing the struts. So far they are perfect and have driven a few thousand miles with no issues.
Super Member
Joined: Mar 2010
Posts: 684
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From: Lebanon
2007 BMW 550i
I ran 235/45/17 rear tires instead of 225/45/17 on my w203 for a time. My tires wouldn't get the correct traction. I used to use Toyo T1R tires at the time and the car used to literally start jumping in the back if I tried to burnout because of they were so sticky. When I switched to the wider tire that stopped happening, in fact I could actually drift the car when the tires were still new (still Toyo T1R tires). I changed out my rear shocks a year later; but I cant tell you if that's related in anyway. So still not recommended in my book.
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NO LONGER ACTIVE
My set of Michelin Pilot A/S tires on the rear are nearly bald after 15K miles. Talk about drifting! I've been playing around with ESP off (just the dash button not "dyno mode") and I can leave some really nice "S" shaped marks on the pavement with a full-throttle takeoff. The entrance to my office building is a sharp right-hand curve and it's always wet from a leaky sprinkler head. I have mastered the perfect "drift" running up that turn. I have tried some dyno mode antics and, well, it's pretty scary without a locking diff - no control 
Super Member
Joined: Mar 2010
Posts: 684
Likes: 14
From: Lebanon
2007 BMW 550i
My set of Michelin Pilot A/S tires on the rear are nearly bald after 15K miles. Talk about drifting! I've been playing around with ESP off (just the dash button not "dyno mode") and I can leave some really nice "S" shaped marks on the pavement with a full-throttle takeoff. The entrance to my office building is a sharp right-hand curve and it's always wet from a leaky sprinkler head. I have mastered the perfect "drift" running up that turn. I have tried some dyno mode antics and, well, it's pretty scary without a locking diff - no control
. Eventually after about a month I managed to rip the tread clear off the tire I then changed up to Kumho KU39 tires. After a year and 30,000KM they still stick to the asphalt. But still had my fun during the winter with snow and all.
