CLA 180 2017 scrapes on everything

[Sohrab Gulam]

Hi guys, really need some help.
So I’ve had my CLA since March this year, bought it as an approved used car from Mercedes.

However, ive realised that the front bumper and undertray scrapes on every speed bump I go over. I’ve gone over slow, to the side but still scrapes. Been to MB to have a look if everything is okay, they gave it back as everything seems normal.

So my only hope now is to change tyres for a little ground clearance. I currently have 225/40/18 as standard but was wanting to know if I put 225/45/18, would this affect anything? Is it a good idea? Any suggestions?
Thanks guys

 

[dry run]

Strange?? Could the previous owner have had it lowered?

I don't think it's a good idea to go messing with the tyre sizes and risk upsetting the numerous safety/convenience features that these cars have

 

[Sohrab Gulam]

Nope, been to Mercedes just last week, they checked everything, apparently all is normal.

do you have any other suggestions? I’m really confused at this point :/

 

[Sohrab Gulam]

Some people have mentioned upgraded suspension/coil overs but I’m not sure

 

[C16RKC]

Perhaps Mercedes are being less than honest as they are the ones who sold you the car, and don't want to address the issue?

If the front bumper is scraping it's either very high speed bumps, a lowered car, or someone has fitted an additional splitter at the front. I've never seen a standard car scrape on speed bumps; outside of things like Lamborghinis of course.

On the other hand, if the undertray is scraping too, then it can only be either massive speed bumps, or a lowered car.

I might suggest asking a couple of people who have the same car to measure the gap between the wheel arch and tyre (or wheel arch to floor), then check to see if your car is the same. Might be some difference between AMG/standard models, so would try and find the same car model. You may also be able to measure similar cars on the dealer forcourt if they are OK with it?

Hopefully another CLA owner will see this post - but you might try posting it in the suspension section too?

Suspension, Steering & Brakes

forums.mercedesclub.org.uk

 

[Tony Dyson]

There will always be those who will recommend spending money on fixing a perceived problem, +1 as above, and get a 2nd opinion from a competing dealership, what warranty do you have left ?

 

[C16RKC]

Yes I did not think of that - taking it to a different dealer would be a good idea.

Hopefully they have a similar spec CLA on their forecourt to compare it with.

 

[Sohrab Gulam]

It’s a 2017 model, I do have extended 2 years warranty

 

[Sohrab Gulam]

Perhaps Mercedes are being less than honest as they are the ones who sold you the car, and don't want to address the issue?

If the front bumper is scraping it's either very high speed bumps, a lowered car, or someone has fitted an additional splitter at the front. I've never seen a standard car scrape on speed bumps; outside of things like Lamborghinis of course.

On the other hand, if the undertray is scraping too, then it can only be either massive speed bumps, or a lowered car.

I might suggest asking a couple of people who have the same car to measure the gap between the wheel arch and tyre (or wheel arch to floor), then check to see if your car is the same. Might be some difference between AMG/standard models, so would try and find the same car model. You may also be able to measure similar cars on the dealer forcourt if they are OK with it?

Hopefully another CLA owner will see this post - but you might try posting it in the suspension section too?

Suspension, Steering & Brakes

forums.mercedesclub.org.uk

I took the car to another MB dealership to be looked at for this same reason but they said everything seems normal

 

[C16RKC]

Hmmm that's odd.

I find it very hard to believe a standard car will scape on a speed bump.

But the only way to prove it is lowered will be to get a comparison with a similar car.

Out of interest is it every speed bump, or just a particular one? - I remember back in my college days they fitted an enormous speed bump in the college car park that some caught their cars on. It had to be modified with extra concrete due to the complaints.

 

[Sohrab Gulam]

It’s most speed bumps, not every sorry, the mechanic did say the cla front is really low so it’s normal :/ just trying to find something that will help

 

[Sohrab Gulam]

Would changing the tyre size from 225/40 to 225/45 be that bad of an idea?

 

[mioba]

Put your vin in one of the vin decoders and see what the original set up of the car was, could be someone swapped out tyres in the past.

Cheers

 

[Tony Dyson]

For the cost and fitting of four new tyres you will gain an additional 11.25mm or 0.443" in old money, height from the road surface to the underside of the car, the pitfalls will be:

1. The larger profile tyre will mean your speedo will indicate a slower speed than you will actually be travelling at!​
2. The larger profile tyre will have less room to travel within the wheel arch than normal and therefore a better chance of making accidental contact with the inner/wheel arch​
3. If the noises you hear are in fact being generated by the tyre’s contact within a wheel arch/es, you will be making matters worse!​
4. You will have to declare the upsize in tyre to your insurers and seek their approval or advice before committing as this will constitute a modification.​

The contact you describe simply shouldn’t be happening, if MB have twice confirmed there is nothing wrong with the car then I can only suggest you’re driving too fast! Slow down!

 

[Ron240]

I have a CLA but it is the newer current shape version. My tyres are standard 225/45/18
As to be expected it has no problems with any type of speed bump.

 

[Sohrab Gulam]

I drive over the speed bumps at maybe 5-10 mph, that can’t be too fast can it I’m just wondering if it’s possible to get the same size tyre but with a bigger tyre wall, of course it won’t be too big to touch or scrape the tyre wall, or do you guys have any other suggestions

 

[Tony Dyson]

I drive over the speed bumps at maybe 5-10 mph, that can’t be too fast can it I’m just wondering if it’s possible to get the same size tyre but with a bigger tyre wall, of course it won’t be too big to touch or scrape the tyre wall, or do you guys have any other suggestions

Have you checked the tyre guide behind your fuel flap to confirm you already have the correct size tyre fitted to your car? Your current tyre size should be indicated there, if the 225/45 is listed then someone has retrofitted a smaller tyre than OEM and the MB dealerships should have picked this up?

 

[Sohrab Gulam]

I’ve checked and my tyres are the correct ones for my car, I now have 225/40r18

 

[Sohrab Gulam]

This is what I have

 

[Tony Dyson]

Strictly speaking you would need to change the wheel as well as a Tyre to increase a wall height as you already have the bigger wall height fitted with your 225/40/R18's. But the wheel change would be to a smaller 17" cancelling out the gain you are trying to achieve!
I don't know what to suggest, you shouldn't have to change wheels and tyres, your car simply shouldn't be grounding as you describe, I would wait a little longer for other CLA owners to contribute and hopefully come up with a solution, good luck!