Firm Ride and Road noise

[Raymond28]

Hello every one I am new in the club, My name is Ray I am 28 years old from Malta Europe. I own a new Renault Megane hatchback Expression 1.5 cdi 106 BHP , After 3 years I had no problems very Reliable car everthing is still working and no problems with the electrics yet, I have done 20,000 km on the clock. I am proud with this car but My megane is fitted with factory 16'' 205/55 wheels with continental tyres , after a long run especialy with AC on and in a warm day the ride become's Noisy and firm and figits at low speed, and pothols,bumps make themselfs felt into the steering and makes a rattle from the wheels , I keep the tyre pressures 20 bar all less than the Driver's handbook Suggest 22 bar front and 20 bar rear non motorway [drver's handbook] I reduced the pressure for our roads because many roads in Malta are still poor, I would like to know if the problem is comming from the wheels or from the suspension , and why at high speed over 120km the car becomes very stable and more comfortable ? I also hate the passanger seat belt bucks when swings over poor roads but that is not a problem when i am drving alone I Clip the belt into the seat and want swing.

I love this car so much the build quality is of high standard , its comfortable, great fuel economy and low running costs and Dealer in Malta is very good and helpfull ,

Sometimes the steering is a bit boring u need a firm hand but road holding is very good it holds the road strongly and my megane does'nt Roll it remains flat in Corners there is some body roll in hard cornering but few its not a rolly polly like old Citroen's and Renault's .
Any help please ? about my problem of figity low speed ride and road noise

[GTDave]

I dont know whether it may be the same principle, but I do a lot of mountain bike racing, and I vary my tyre pressure depending on what type of surfaces im racing on, and how muddy or damp it is etc... but I adjust my suspension whenever I adjust my tyre pressures.

This is because my suspension is designed to react a certain way to the input it receives from the trail. When you reduce the tyre pressure, the tyre absorbs more of the shocks, and therefore reduces the forces exerted on the suspension, so I reduce the damping on my suspension also...

As I say, I dunno if this might apply to cars too, but having softer tyres may mean that the suspension is not absorbing shocks as efficiently as the shocks exerted on it are numbed... hope I make sense...

[Raymond28]

hi,

you mean with lower tyre pressures the ride will be better? I think that the problem is comming from the wheels/tyres after long run the pressures expand by 2psi or 2 bar , and another thing when I spray w40 or solvit spray on the shockubsorbers and springs the ride becomes more smooth and comfortable , but I think that the factory continental tyres are not very good for ride comfort the Compound is hard .

you drive a megane too?

regards ,

Ray

[AlexB]

Raymond,
I am sorry to point out that 2bar is significantly different from 2psi. The latter is the normal pressure increase due to fast driving and the former means that your car is on fire. Spraying WD40 on springs and shocks is useless as they do not rub against anything. The spray may have cooling effect (potentially) or may get in the bushes (which is bad in the long term). So, more investigation is required, I am afraid...