Wheel Size Question
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2012 C300 Sport
Wheel Size Question
While getting new tires, I was informed and shown bead seat corrosion heavy on 1 wheel along with a crack there. I decided to then order new wheels that I can use for the time being before shopping around for what I'd truly like in the future. However, I see now that they ordered a different size than the factory setup....?
I have a 2012 C300 Sport with the staggered setup of 225/45 R17 on the front and 245/40 R17 in the rear and the wheel width of 7.5" in the front and 8.5" in the rear (original wheels). I now see the wheels that were ordered are only 7" width for the front and 8" for the rear. Is this going to be an issue? What change(s) will I notice with this? I'm not usually a guy who deviates from the factory setup for tires and wheels on any of my vehicles.
Edit: If these smaller wheels will work with that size tire, is there around a specific offset that would be optimal?
I have a 2012 C300 Sport with the staggered setup of 225/45 R17 on the front and 245/40 R17 in the rear and the wheel width of 7.5" in the front and 8.5" in the rear (original wheels). I now see the wheels that were ordered are only 7" width for the front and 8" for the rear. Is this going to be an issue? What change(s) will I notice with this? I'm not usually a guy who deviates from the factory setup for tires and wheels on any of my vehicles.
Edit: If these smaller wheels will work with that size tire, is there around a specific offset that would be optimal?
Last edited by doncab2; Dec 26, 2025 at 05:47 PM. Reason: Added offset question
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2021 GLB250 FWD, 2023 GLA250 FWD, 2013 C250, 2015 GLK350, 2005 ML350SE, 2003 E320
Minimum rim width for 225/45R17 is 7.0 inches and for 245/40R17 is 8.0 inches. So these rim widths are okay. Check the offset on the newly ordered wheels against the factory wheels. Wheel rim width using the factory tire sizes does not affect offset. If the new rims have the same offset as factory, everything is fine. To keep the factory handling characteristics, the new rims should be no more than -5mm to +0mm different from factory. Different tire sizes may give more options.
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From: Northern Indiana
2014 c300 w204.080 3.5 v6
If I were you and buying rims get them all four the size of the rear so you can now rotate tires. This gives way better tire wear and I see no need for staggered tire sizes on these cars. My 2c
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W204 C250 Sport (AMG Package with Pano Roof)
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2012 C300 Sport
Minimum rim width for 225/45R17 is 7.0 inches and for 245/40R17 is 8.0 inches. So these rim widths are okay. Check the offset on the newly ordered wheels against the factory wheels. Wheel rim width using the factory tire sizes does not affect offset. If the new rims have the same offset as factory, everything is fine. To keep the factory handling characteristics, the new rims should be no more than -5mm to +0mm different from factory. Different tire sizes may give more options.
Front wheels the offset range is 45-49 and listed as 17x7.5 47
Rear wheels the offset range is 56-60 and listed as 17x8.5 58
The new wheels are listed as:
Front 17x7 42
Rear 17x8 38
The front would be near/within the -5 mm, but the rears are way off. What would need to be done to be able to use them? Or is this just a flat out no-go situation as it may stress the suspension too much?
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2021 GLB250 FWD, 2023 GLA250 FWD, 2013 C250, 2015 GLK350, 2005 ML350SE, 2003 E320
The front wheels should be fine. The rear wheels need to be checked for fender clearance after the tires are on because they will move out about ¾”. There is no real issue with suspension stresses at this offset, especially on the rears. The slightly wider rear stance may increase the tendency to understeer just a bit.
