2006 RX400h - Are They All Like This?

[ntl]

Hi! I'm looking to buy an RX of some sort.

I drove an '06 RX400h today and found the following:

• The steering was quite heavy in comparison to an RX350 I've driven in the same generation, and the steering wheel seemed to tug left and right at higher speeds (and in fact drift left, although that could have been due to lower tyre pressure on that side). It was considerably heavier at lower speeds too. Not as nice and relaxing as the 350. I could imagine it becoming tiring.
• The throttle response didn't seem as sharp as the RX350's from a standstill, either. The 350 was eager to launch from the slightest tap of the throttle; the 400h didn't seem to have the same urgency, but did have more power on the move. Perhaps I expected too much of the electric motors? Maybe this is what CVTs are like?
• I noticed a very strong smell of eggs while testing the air conditioning which periodically fired the engine up - maybe the catalytic convertor? Is that a bad sign?

Any thoughts on the above?

Thanks!

[Spock66]

As with any 16-year old car condition and history are essential, this one certainly sounds past it's prime. Pulling to one side may be due to tyre pressure but more likely wear of steering / suspension components.

I'd suggest you pass on this one.

[ntl]

8 hours ago, Spock66 said:

As with any 16-year old car condition and history are essential, this one certainly sounds past it's prime. Pulling to one side may be due to tyre pressure but more likely wear of steering / suspension components.

I'd suggest you pass on this one.

That's disappointing. What sort of steering system does the XU30 RX400h use? Are we talking an expensive fix?

[PCM]

8 hours ago, Spock66 said:

 

I'd suggest you pass on this one.

+1 

[ntl]

Thanks guys. In the past I've always had worn components replaced; do you think a vehicle with steering behaviour like this is not worth repairing? Or is it just that there are likely to be others out there in better shape? I could try negotiating the price with the steering in mind.

Any comment on how the RX400h steering should feel compared to the petrol-only models? I know it can be difficult to put into words, but the 350 and 300s that I've driven were 'light and fluffy' without much road feel (not a problem for this type of vehicle, mind), and the 400h had more road feel but was also noticeably heavier. It kind of reminded me of my BMW in a way, but that is designed to have heavier steering.

[PCM]

I would due the usual due diligence... MOT history, service history etc.

Sounds like an unloved car to me. What else might need fixing?

I would pass...

[kenhall]

2 hours ago, ntl said:

That's disappointing. What sort of steering system does the XU30 RX400h use? Are we talking an expensive fix?

My RX400h has the later electric motor assisted steering rack and associated electronic control with some parameters adjustable using Techstream eg centring. Assistance is high at low speeds and becomes lower (firmer) as speed increases.

Correct me if I’m wrong but I believe that earlier RX models used a more conventional hydraulically assisted steering rack which might explain some differences.

Edited February 24, 2022 by kenhall
Extra text

[Spock66]

So a current RX new is around £60k, no doubt a 2006 version was a similar price in real terms with adjustment for inflation, so a premium priced luxury vehicle which will have associated maintenance costs.

So at 16-years old clearly price will be much lower, and you may end up with a bargain, equally you may end up with just a money-pit. I think buying a 16-year old car is a different experience to keeping and running a car for 16-years.  Bear in mind the average life of a car in the UK is around 13/14 years, typically they have not rusted away or have major mechanical faults, but just not economic to repair in rip off Britain.

[Herbie]

2 hours ago, kenhall said:

My RX400h has the later electric motor assisted steering rack and associated electronic control

 

2 hours ago, kenhall said:

Correct me if I’m wrong but I believe that earlier RX models used a more conventional hydraulically assisted steering rack

The RX300, 330 and 350 use conventional steering.

The RX400h and 450h use an electric motor for steering, as do all hybrids. In a hybrid, the petrol engine doesn't run all the time and the hybrid system decides when to run it and when to stop it. Imagine the engine cutting out going round a corner or bend and you lose power steering - this is why hybrids use an electric motor.

[Russell Wheeler]

Doesnt sound like a good one, the rx400 I have goes like a rocket (Specs are something like 0-60 in 7.5 seconds), although with a CVT you don't feel it like a conventional car. Steering in mine is light, with not a lot of feeling, no pulling to the left or right at all. No funny smells either.

[JBPRX400h]

Just a thought. Was it particularly winy when you drove it today? These cars (as are any tall vehicles) are quite susceptible to cross winds.

[JBPRX400h]

Whoops!!

I meant Was it particularly windy when you drove it today? 

 

[ColinBarber]

10 hours ago, ntl said:

Any comment on how the RX400h steering should feel compared to the petrol-only models?

The 400h suffers from torque steer. Under full throttle the steering will fight you a little and it becomes light. This is due to the 400h being predominately FWD - you don't get this with the RX350.

[ntl]

Thanks all. I ended up buying it after speaking to a Lexus tech who explained most of what I'd experienced (and what some of you guys pointed out):

• Electric power steering vs hydraulic in the 350 & 300
• FWD bias causing torque steer vs the RWD bias in the 350/300 - Colin, your description matches perfectly!
• Sensitivity to cheap / mismatched tyres (in terms of pressure, tread, or direction)
• FWD + electric + CVT vs the above for a different launch experience

I pumped the tyres up to 2.2 bar all round and the drive was much better. I've also ordered a set of four CrossClimate SUVs to be fitted over the weekend along with an alignment to improve things further, and will look into calibrating the steering with software after that.

[ntl]

5 hours ago, JBPRX400h said:

Whoops!!

I meant Was it particularly windy when you drove it today? 

 

Yeah, it wasn't great weather. It was even worse on the way back today so I took it very steadily. I'm not used to tall vehicles!

[ntl]

7 hours ago, Russell Wheeler said:

Doesnt sound like a good one, the rx400 I have goes like a rocket (Specs are something like 0-60 in 7.5 seconds), although with a CVT you don't feel it like a conventional car. Steering in mine is light, with not a lot of feeling, no pulling to the left or right at all. No funny smells either.

I haven't tried a flat-out launch yet, but it's got plenty of power on the move. The RX350 just felt way more eager though - I guess the RWD bias + conventional drivetrain has something to do with that. The 350 reminded me of how older RWD cars with auto boxes felt - barely any latency between throttle mashing and sending the torque to the rear.

[ntl]

I got the tyres fitted this morning. It feels a lot better in ride quality and steering! It stays centred a lot better now, although I'm still going to get a four-wheel alignment done once I've had the suspension checked over.

I was a bit disappointed with the fuel economy; I got around 22mpg for the trip to the fitters and back (10 miles roundtrip through a town, mostly 30mph roads with light traffic). The hybrid Battery showed that it was nearly full the whole time.

[ColinBarber]

On 2/26/2022 at 12:31 PM, ntl said:

I was a bit disappointed with the fuel economy; I got around 22mpg for the trip to the fitters and back (10 miles roundtrip through a town, mostly 30mph roads with light traffic). The hybrid battery showed that it was nearly full the whole time.

Cold weather; I suspect the engine was on most of the time to heat the cabin. You also need to adjust your driving slightly to get the best from a hybrid - accelerate to cruising speed, back off to allow the engine to cut out and then apply throttle to maintain speed without causing the engine to come back on again.

[ntl]

On 2/26/2022 at 1:11 PM, ColinBarber said:

Cold weather; I suspect the engine was on most of the time to heat the cabin. You also need to adjust your driving slightly to get the best from a hybrid - accelerate to cruising speed, back off to allow the engine to cut out and then apply throttle to maintain speed without causing the engine to come back on again.

True, the climate was set to 22c and it was cold out. Thanks for the driving tips. I'll try them next time I go out.

[Spacewagon52]

Please keep us informed about how you are getting on with the car. MPG is very hard to judge on such a short trip. Reset the mpg and run it for a full tank. On very short runs I have achieved similar results in winter. As Colin has stated, short runs when cold kill mpg. You should be getting around 25 to 30 mpg depending on the above. The steering on the RX400h feels totally different from my previous RX300. If you follow Colin's advice on driving style you will gain maximum mpg. It does take a little getting used to. What mileage do you have on the car?

[Rabbers]

On 2/25/2022 at 12:32 AM, ntl said:

… I pumped the tyres up to 2.2 bar all round and the drive was much better. ….

Isn’t that still a bit too low in any case?

[ntl]

54 minutes ago, Spacewagon52 said:

Please keep us informed about how you are getting on with the car. MPG is very hard to judge on such a short trip. Reset the mpg and run it for a full tank. On very short runs I have achieved similar results in winter. As Colin has stated, short runs when cold kill mpg. You should be getting around 25 to 30 mpg depending on the above. The steering on the RX400h feels totally different from my previous RX300. If you follow Colin's advice on driving style you will gain maximum mpg. It does take a little getting used to. What mileage do you have on the car?

Thanks, I will. It's got around 160k on it, but hides it very well.

[ntl]

50 minutes ago, Rabbers said:

Isn’t that still a bit too low in any case?

I got that from the sticker on the door jamb, which states 2.2 or 2.3 depending on what appears to be the speed rating. I've put 2.3 into these new ones and it rides very nicely. I love putting good quality tyres on a vehicle. It makes such a difference, and the CrossClimates are some of the best I've found.