RX450H rocky ride

[Rocky ride]

Hello I am new to the forum but have had several Lexus vehicles a GS300 was my first my present is a 2002 plate ls430 My wife had an Rx300 Sel 04 plate and she upgraded to a RX45H 13 premium, Now here is the reason why I joined.... the ride in the 04 rx300 was very comfortable however the ride in the Rx450 H premium has what can only be described as an excessive  side to side movement even on minor road imperfections. My question to everybody is this because of the increased wheel size to 19 inch where as the o4 plate had 18 inch wheels it’s just that it seems to want to jolt you side to side however going over speed bumps are easier and more cushioned....by the way lexus say the car has no problems mechanically or otherwise..We look forward to your replies.....

[NemesisUK]

I would have thought upping the wheel size will reduce roll as there is that little bit less tyre sidewall to flex.

[Rocky ride]

Thanks Peter well this is why we are confused some say that the higher tyre wall on the 18 inch will cushion the road bumps and others say that the 19 inch will stop the side to side jolt we are confused as the rx450 h is great on speed bumps but it does Want to jolt side to side which we did not notice in the Rx300 to this extent.

[ColinBarber]

The newer RXs are stiffer, and therefore don't roll as much, compared to the serIes I and II models. But with less play in the tyre wall you can get jolted from side to side on pothole etc.

As you have a Premium grade you have air suspension, have you tried lowering the ride height?

[Rocky ride]

Hello Colin thanks for the reply we have been driving around in normal mode but we will give it a go in low mode having just re read page  322 onwards. I will let you know how it goes.

[Rocky ride]

Hello Colin thanks for the advice went for a drive in low mode .....yes a much stiffer ride less side to side motion but you do feel the potholes more. It did seem to be a similar ride to the rx300 but slightly more road noise and more feeling the road undulations through the seat......sounds stupid but I miss the RX300 yes it was noisier and had less gizmos eg HUD Bluetooth and less speakers but it’s definitely a case of you really don’t appreciate what you have until it’s gone thanks steve.

[sorcerer]

I'm afraid that I have no answer for you, just an observation.

We had an '05-plate RX300 for two years and traded it in for a 63-plate RX450h Advance just over 5 months ago. I can truthfully say that we see no excessive side to side movement and it is honestly the most comfortable car we've ever had in more than 43 years of motoring, giving a superb ride in every way.

[rayaans]

The air suspension on the 450hs don't make much difference to the ride quality. 

The 450h is a lot heavier and due to safety regulations, SUVs do have to be stiffer to prevent rolling as much as possible. 

A tyre change might help. The 450h has almost no road noise at all. 

 

[Rocky ride]

Hello John  and Rayaan thank you for the replies yes I agree that the road noise level when driving in normal mode is almost non existent in lower mode it does increse but it was a very firm ride and where you gained on the side to side motion you lost with the thud of the bumps maybe it’s just one of those cars I agree it is excellent in every other way ....my ls 430 also has air suspension agreed it is lower body but it is a. Totally different drive experience. My initial thoughts were its just because the tyres are bigger than the older rx300 we changed it for my thinking was the extra tyre wall would cushion the  drive and stop this side to side motion... however if the  factory set up is for a stiffer body as Colin has pointed out then maybe it is just something we will have to live with. I am curious John what size wheels do you have  are they also 19 inch?

[sorcerer]

8 hours ago, Rocky ride said:

I am curious John what size wheels do you have  are they also 19 inch?

Yes they are Steve - Goodyear Vector 4Seasons Gen 2 on the rear, Bridgestone Duellers on the front (at least for another couple of months - at £180 each I couldn't justify changing the fronts to Goodyears while they still had so much tread left).

[Mr Vlad]

If I were you Steve I'd go test drive a different RX premier. Why? Because my thoughts are that unfortunately you have one of the very few rogue cars. I've had 2 exact same is300h and both were like chalk and cheese. Go test drive another and give it a good test drive. I think you'll find the car you test will be totally different to yours. Make sure tho it's the same year and model.

[Rocky ride]

Vladimir that sounds like a good plan the car was bought for my wife to replace her rx300 o4 plate she had read all the reviews and having had several lexus vehicles before we just took it as a given that there would be no problems but everything is excellent except the sideways jolt yes it’s quiet in normal level mode yes it takes road humps easier than the older model but it’s not as comfortable we will try another premier can I as what was your problem with the  is300 h ? Was it similar with the side to side ride ?

[Mr Vlad]

Hi Steve. The differences between the 2 is300h cars were numerous. Ride, comfort and the mark levinson system was hite  (with a S) . 1st car lasted 5 weeks. 2nd superb car lasted about a year but changed it to my current RX450h f sport with Mark Levinson. I'd have liked the premium but the f sport looks so much better. It's ride is very good with no issues.

[katabrontes]

I noticed this problem when we tests drove a Jeep Grand Cherokee. Many years ago.  We bought a Toyota Surf then which was a really great car and an excellent workhorse until the Aircon finally failed and we changed it for an RX 350 which I like a lot.

[sorcerer]

Vlad's idea is a good one but I'd go one further - try an Advance or an F Sport. Just one step down from the Premier but without air suspension. I've never owned or driven a car with air suspension but I have been a passenger in them many times and I really don't think they offer anything over and above 'traditional' suspension systems except a whole new level of complexity for little or no return ride-wise.