Ml 270 larger tyres but no power

[21j]

Hi, I have fitted 31.6" tyres and now I have very low power or torque most of the time, but especially pulling off or on a hill.
Anyone have any ideas.
Does the tyre size need to be changed in the ECU?
I have since unplugged the yaw sensor and lateral acceleration sensor but it didn't do anything.
Yes I was getting the odd flashing of esp light on some bends and the odd one wheel being brakes.
It's ml270 2001.
Thanks
John

 

[mersum1es]

Are all tyres same size? Some speed sensor is giving ecu indication that traction is loosen, van be sensor (reluctor ring) fault too.

 

[Botus]

if the tyres have a much bigger circumference you'll have raised the gearing - this makes for slow acceleration and whilst it will theoretically have a much higher top speed, it may have insufficient power to get there

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[ajlsl600]

Looks like remap territory? Or go back to std

 

[brandwooddixon]

Hi, I have fitted 31.6" tyres ...

I hope that is overall diameter and not rim size.
What is the actual tyre size fitted?
If the tyres are a larger size than specified then you will be increasing the gearing of the final drive. This will decrease your acceleration but increase your road speed (note that your indicated road speed will be less than your actual road speed).

 

[stumo]

I have bigger tyres on all my ML270's and a friend has even bigger ones on his. Its not the tyre size thats the issue.

What has happened is you are in limp mode due to some other issue.

Since you noticed it just after you change the tyres, my money would be on something like a wheelspeed sensor, or wire has been broken. Or dirt or rust has been dislodged and one or more tone rings are damaged/clogged. This is supported by the BAS/ESP light and random ESP engagement. You could read the codes (using a known proper scanner) and they will tell you exactly what's wrong.

 

[NJS5]

21J - Welcome

As already asked what is the actual tyre size please?

Do be aware that if you are in the UK, and have fitted "non-standard" size tyres you should inform your insurers.

Good luck

NJSS

 

[NJS5]

Does this help ? "Largest tyre size 225/75 R16"

 

[Blobcat]

21J - Welcome

As already asked what is the actual tyre size please?

Do be aware that if you are in the UK, and have fitted "non-standard" size tyres you should inform your insurers.

Good luck

NJSS

Tyre size below

 

[stumo]

Like I said. Its not the tyre size thats the issue. Its the process of R and I the wheels that has precipitated a fault. I have ML270's that have run bigger than 270/70R17 for well over a decade.