aieu77

My suspension airmatic is very stiff, already make all the tests and no faults found but, I've change the wheels to 18",the oldest 16", causing also vibration on rear wheels.
wheels and tyres are in good condition.

I do not know what to do anymore.

Plutoe

To help us-----what tests, please describe??

I would put the 16 inch wheels on!!

homeofstone

Check the tire balance. Vibration cause may be flex disc or driveshaft.

aieu77

I put the car on the mechanic and he made the tests to the all system of the suspension.He regulated the suspension but still very stiff.

Plutoe

That's simple, take it back to your mechanic and have him adjust to your liking--whats the problem!!!

PS: Why can't you do that from your shifter AIRmatic controls!!!!

aieu77

I don't know if it's like that...???Because there some values/parameters that the fabricant have, right?