Firm Ride - Tyres/rims ?

[rogerthedoger]

Dear fellow IS300h owners,

I have had my new IS300h Premier for 5 months now. I find it to be an excellent choice as a saloon with comfort and nice features to enjoy, and I do love it a lot.

The only gripe I now have, and indeed have seen comments from others on, is that with the [admittedly very nice] 18" rims and wide bootlace tyres you feel every dammed pebble on the road. My partner is complaining that a trip of more than an hour is uncomfortable, and, as usually happens, since she mentioned it, I am now conscious of the bumps too. My previous car was a GS250 F sport and that was bit sensitive to road surface - but I do think this IS is a bit worse.

The ride on modern, smooth, tarmac is great.

Does anyone agree that if I were to swap the 18" for 17" rims that would improve the isolation from the impact of the average British road surface??

[rmccardal]

Find my exec very comfortable on the 17's bit of extra rubber/air does make a noticeable difference.

[DJP]

Have a check of the tyre pressures too, mine were set at 42 psi and handbook says 36. I reset them and I have noticed the difference. Just a thought.

Sent from my iPad using Lexus OC

[steveledzep]

I could take the 18s off you in exchange for my 17s !!! Lol !

[stevet]

Plus your GS F sport would of been on 19" wheels.

[rayaans]

Could be that your partner has the seat in an awkward position?

You could always put tyres on with more sidewall - may affect the speedo though

[gtb5]

18 would be more bumpy than 17 and 16 would provide a better ride than 17 due to tire thickness, can't have both worlds.

[BigChange]

Seems that I can feel every imperfection in the road.  And there are  many. Could it be the tyres - 225/45 R17 Yokohama BluEarth E51 ?? The ride is as firm as my previous car's (BMW) runflats. Pressures checked regularly with my own gauge. Can anyone suggest a more 'comfortable' tyre ?  Is the suspension adjustable (IS300h Exec) perhaps ?

[Steve44]

Is the car brand new Peter?  Has the dealer taken the transport blocks out during the PDI?? Just a thought........

Suspension isn't adjustable. Ride should be pretty compliant. I've got F-Sport with 18's and its pretty good on all but the worst roads.

What pressure are you inflating too - 33-36psi should be the norm.

[rayaans]

Very odd that people find the ride firm in an Exec! I dont even feel that the ride is truly firm in the F-Sport!! Its nowhere near as firm as 3 series on runflats so something is wrong!

[BigChange]

Thanks for the response.  Car is one year (registered) old today; 11k miles so far and pressures checked at 36psi. Due in to garage next week for annoying creak next to my right shoulder + door movement and will mention firm ride.

[Richard1200]

17 minutes ago, BigChange said:

Thanks for the response.  Car is one year (registered) old today; 11k miles so far and pressures checked at 36psi. Due in to garage next week for annoying creak next to my right shoulder + door movement and will mention firm ride.

That annoying creak by your right ear could be the window. Try just touching the window down button very very lightly so the window drops just a couple of mm to prove the point. It could be the top of the glass in the seal, I put polish on mine and it dissapears fro a while.

[capese21]

I have an IS300h Fsport with 18" wheels.

I recently changed from rock hard original spec Bridgestones to a set of softer sidewall Uniroyal Rainsport 3 tyres.   The ride although still firm is noticeably more comfortable.

 

Ed

[wh05apk]

F1 autocentres currently have the uniroyals at great prices.

[rayaans]

Goodyears have super soft sidewalls might be worth a try

[ganzoom]

15 hours ago, BigChange said:

Seems that I can feel every imperfection in the road.  And there are  many. Could it be the tyres - 225/45 R17 Yokohama BluEarth E51 ?? The ride is as firm as my previous car's (BMW) runflats. Pressures checked regularly with my own gauge. Can anyone suggest a more 'comfortable' tyre ?  Is the suspension adjustable (IS300h Exec) perhaps ?

 

What are you after from the suspension. My personal experience is that the stock suspension set up on our IS300H is the best I've experenced in ANY car. The damping is perfect, and the car isn't upset at all by adverse camber or even pot holes. Yes can 'feel' imprecations in the road but they rarely upset the travel of the car. In my books that's the hallmark of a good suspension set up, communicates to the driver the road surface conditions, but doesn't let bad road surfaces throw the car off the driving line. It's leagues ahead of the stock suspension on my hold BMW 335i, which had horrendous damping.

If your arfter 'softer' suspension you can always try after market springs with different compression rates, but than your need to look at a while customised setup to change the dampers to suit the springs, and that ain't going to be cheap.