Edmunds.com | Inside Line | Auto Observer Your Account | Help | Directory
You are here:
![[F]](http://a332.g.akamai.net/f/332/936/12h/www.edmunds.com/media/townhall/webxicons/site.gif){kind=small}
Forums
Hybrid Vehicles Lexus RX 400h Lexus RX 400h
2334 messages, Last post on Oct 11, 2009 at 10:42 AM
You are in the Lexus RX 400h Forum. Your Host is pf_flyer
|
When I am WOT and the ICE is producing 208HP are you saying half of that drives the generator and then from the generator that half drives MG2... CVT.... If I jack up the rear end of a RWD vehicle with just a simple open diff'l, put it gear with the engine running and hold one wheel stationary with just my little pinky... If you think of the opposite wheel, now spinning rapidly, as MG1, that's the way I thought the CVT in the Prius, RXh and HH worked. Virtually no energy needed at MG1 to prevent the ICE from conveying energy to the roadbed via the opposite end of the diff'l if you want to remain stopped. So how do I overcome the "traction" force of my pinky?? I stop allowing MG1 to "freewheel", in other words I supply it with enough energy to turn it AGAINST the motive force of the engine. Remember that MG1 has a serious mechanical advantage over the ICE via the planetary gearset, so it doesn't take much energy, relatively. I assume the above moves the vehicle in reverse and if I apply AC power to MG1 to AID in supplying motive force the vehicle goes forward. But yes, assuming I am not requiring WOT performance, the ICE torque can be used to to recharge the batteries.
|
|
|
Replying to: rx400hfan (Oct 13, 2005 1:23 pm) Are you confusing "low speed" with constant speed? At a constant speed, even uphill or towing, very little of the ICE capability is required for forward motion, So clearly, it can then be used to recharge the batteries. But if I am accelerating rapidly.... |
|
|
Replying to: wwest (Oct 13, 2005 2:09 pm) You are correct that MG1 will be freewheeling when the ICE is running and the Lexus is stationary, but when you push the accelerator MG1 does not hold back by taking power from the battery it holds back by being a generator and providing the generated power to MG2. Due to the laws of physics while the vehicle is still stationary 100% of the power output of the engine (less slight gear losses) will be through MG1 acting as a generator. This power is directed into MG2 in addition to the battery power. As the vehicle speed increases more and more of the ICE power goes directly to the wheels via the ring gear of the PSD. Since the ring gear of the PSD and MG2 are tied directly together and then to the drive axle their speed is directly tied to vehicle speed. At the point where ICE rpm = MG2 RPM 28% of the power from the ICE will be generating electric through MG1 and 72% will be applied to the drive train. |
|
|
So I am looking to buy a SUV and have narrowed my choices to BMW X5 4.4i and Lexus RX 400h. Both these are quite similarly priced (X5 a little higher). The factors that are important to me are (in no particular order): luxury, performance, reliability and depreciation. Based on my test drive and research that I have done, here's what I have concluded (very simply put): 1. Luxury: Both are good 2. Performance: X5 4.4i has an edge 3. Reliability: Rx 400h wins (based on Lexus's reputation) 4. Depreciation: Not sure here about RX 400h? Lexus RX 330 retains it value quite well, so one can say that so should 400h. But my concern is that Lexus is overpricing 400h because of very limited supply and more demand (simple economics). I will also have to pay MSRP (I am in the Seattle area), though if I wait till next year I may be able to get some tax credit. I am not trying to do the fuel math and I don't care much about that (and you typically lose that anyway), but I believe that RX 400h should be priced higher than a similarly equipped RX 300 just because it has more power (similar to why V8 is priced more than V6). But consider the situation 5 years from now when there is no shortage of hybrid vehicles and there are lot more hybrid models from Lexus & other manufactures. Will the value of 2005 Lexus 400h drop considerably? Why does Edmunds (based on their TMV) think the Lexus will depreciate approx $10,000 in the first year (considerably higher than other SUVs like X5, RX 330)? Did anyone conduct such analysis before deciding to purchase (or not) Rx400h and what did you conclude?
|
|
| Its hard to understand where they get that 10K figure im sure its a guess. Dealers are selling used 400h (admittedly low miles) for about 3K below msrp. I think there will be high demand for the hybrids on the west coast for a long time. I have a 400h with 4300 miles and its been great. I agree it is alot of money for a car, i can justify it for business use. My salesman asked me to consider leasing, as it offers tax advantages, and in three years when you turn yours in it should coincide with the next model RX hybrid. I did purchase mine as i usually keep them for 5 or 6 years. Yes you will have a tax credit next year that is over 2K. The bmw is a great car and better offroad, as the 400h is not reccommended for this type of use. At the same time the Hybrid Synergy Drive in the toyotas has been very reliable as reported by owners online and consumer reports finding it much more reliable than average. To get the best mileage you will have to adopt a hybrid driving style but its makes driving interesting, and you wont feel stressed in traffic jams. The smooth linear power across the whole power band is incredible in the 400h and it is a great combination of safety, options, comfort speed and as you mentioned reliability. Gas is only going to go up and the 400h affords you a no compromises way to deal with that. The real unanswered question for me is the cost of repairs to the HSD if you keep one that is out of warranty. There is no doubt that the parts and labor are going to be expensive. Yes that is 7 years or 100K down the road but it will probably cause me to trade my 400h in earlier, than the longer period i would normally own the car. sorry for the stream of consciousness post but those are my thots. | |
|
Replying to: justg0 (Oct 27, 2005 11:30 pm) |
|
|
both have truly functional, rear torque biased, AWD systems and therefore will be inherently safer in wintertime adverse roadbed conditions and snowchains can be readily used on the rear wheels only, or both back and front. A case in point. The new Lexus AWD GS300 uses the VSC's yaw sensor signal to automatically route engine torque away from the front driveline when the front tire's traction coefficient is needed primarily to prevent loss of directional control. Now if the RX series could just be fitted with the GS300's wet clutch so the engine torque, leading or lagging, could be shifted away from the front in the same circumstances.... The RX series, including the h, are based on a FWD platform and are therefore front torque biased, a circumsatnce that is potentially highly hazardous on a slippery roadbed. Additionally, due to tight suspension clearance at the rear snowchains can ONLY be used at the front resulting in an extreme exacerbation of the wintertime dangers. Also, if it happens that you need to defog the windshield of a BMW you will get INSTANT and PROPER response from the climate control system when you activate the defog/demist/defrost mode. HOT airflow to the interior surface of the windshield and lots of it, even on the hottest of summer days. Whereas with any Toyota or Lexus automatic climate control system you will not only NOT get the proper response in this circumstance these systems will be much more likely to rapidly increase the windshield fogging situation, leaving it up to you to quickly modify the operational charactoristics in order to clear the windshield. The newer, 2004+, RX series is even worse. Just as the A/C is disabled as a result of the OAT declining below ~35F, releasing all of the previously condensed moisture on the evaporator vanes to the process of evaporation into the system airstream, the system also automatically switches to footwell/windshield air outflow mode. Up until this moment the interior windshield surface has recieved no warming airflow and now its CHILLED surface may very well be subjected to a super-saturated, very HUMID system airflow. ZAP!! You're blind, no forward vision! Be careful out there.
|
|
|
|
|
Latest CR survey for reliability, http://www.consumerreports.org/main/detailv4.jsp?CONTENT%3C%3Ecnt_id=754189&FOLDER%3C%3Efo- lder_id=113261&ASSORTMENT%3C%3East_id=333137&bmUID=1130553212850 http://www.cnn.com/2005/AUTOS/10/26/cr_most_reliable/index.html Very impressive start for the 400h. I have had zero problems in the first 8,000 miles. |
|
| 99 out of 100 RX400h owners will report no problems. | |
You are here:
Forums
Hybrid Vehicles Lexus RX 400h Lexus RX 400h
New? Join Now!
Forum Tools
Search Forums
Browse by Vehicle
2008 Lexus RX 400h
Browse by Board
Browse by Topic
Today's Chats
