User 41924

We bought our 450h because it was the right color! Mileage had nothing to do with the decision AT ALL, and we still consider it a secondary bonus at best. I was completely uninformed about hybrids and totally unprepared to make an INTELLIGENT decision about buying one, but it turned out to have been a great decision for us.

It's a longer story, but we needed to get rid of our 2010 RX350 ASAP, and the only color my wife liked was Starfire Pearl (like our 350). They didn't have any SFP 350s in stock, so the salesman asked if we were interested in the 450h. The initial answer was "no", but we decided to drive it anyway. The difference was HUGE. It was more comfortable, it rode far better, and it handled WAY better (I can't explain it!). While we both liked our 350, the improvement of the 450h was undeniable, and we loved it. My ONLY issue at the time was with the CVTransmission. It took me a long time to get past the sound of not shifting, but after a little over a year I hardly notice it any more.

Besides, I'm sort of a geek. After reading a LOT about the CVT and the Atkinson style internal combustion engine, I have come to really appreciate the technology and innovation in the car, and am now a full blown believer. Although I'm still not convinced there is a monetary benefit of owning a hybrid ....

Droid13

If we are getting into the weeds here, all 3 can act as both a motor and generator. In fact, there is a special mode, occurs not too often, where "MG2", the "front propulsive", actually acts as a generator (and not for charging) to drive "MG1", the "starter", the reverse of what is common. This happens when the engine is operating at mid rpms with very little load. In conditions like this, engines are not very efficient. This special mode uses electricity generated from the wheels to pass power to MG1, the "starter", to create a resistive load on the engine. Seems counter-productive, but this slight self induced additional load on the engine forces it into a more efficient power state. It's tough to see on the rx450h (maybe weight or quietness), but on my Hybrid Camry I could tell when it occurred easily. Driving along nice, steady and gently and then suddenly the engine rpms drop and a rumble is heard as the load on the engine increases (imagine driving at 25mph in 5th gear on a standard), and the instant mileage meter doubles. It was possible to cruise steady and level at 60-80 mpg in this mode but any slight change would drop the system back to standard operation. It is the theoretical sweet spot, maximum efficiency without relying on battery power.

vlad_a

Your source is incorrect. Here is a really cool demo of how Toyota Power Split Device works.
As you can see, both electric motors are working in sync with the engine. So simple, yet ingenious. There's no transmission, per se.

Aptosuser

I think I need to read Hybrids for Idiots.

VVRX

Agreed! I could not have said it better myself.

websailor

After you do, please paraphrase it for us. Why does pressing the EV button feel like I'm in Las Vegas playing the slot machines?

It took us several tries again today to finally shut the Nav Lady up again after we used the navigation for a while. I wish I had an optional setting that is "End navigation when within 50 miles of home". It is very handy on long trip, and sometimes around town, but most of us know the way home from the major roads in our areas from 50 miles out.

Ernie

ericsan13

Excellent demo, thanks for sharing. It's very interesting that only the traction motor really affects the speed. They need to add a demo for acceleration.

So is MG1 charging the battery when it has positive RPM? How does braking affect charging?

cflutist

We need that too. Pulled into the garage today and was wondering why the Parking Assist wasn't beeping at us? Had to pull out the manual from the secret compartment to find out that dear hubby Websailor had inadvertently turned it off when he was playing with the steering wheel buttons on our way home from our road trip.

Aptosuser

Yeah, I did that once. My wife is driving me to medical appointments until I'm fit enough to get behind the wheel again. She's been driving the car exclusively since March 3. We filled up today on our way to Redwood City (another appointment). We'd gone 400 miles between fill-ups. She averaged 30.8 mpg; best ever for us. I gotta start driving more like she drives.

vlad_a

Well, the traction motor is fixed to the driving axle. However, it is the combination of all 3 that changes the speed.

When braking, a load will be put on the MG2, which will create opposite forces, producing energy. This energy will be turned into electricity and stored in the battery. MG1 could be assisting with this process, and creating more energy to be stored. Or, they could be pinned against each other to convert energy into heat through the inverter. And the gas engine could be engine-braking at the same time, which would force both MG1 and MG2 to produce energy.

There are so many possibilities with this design.
And it is so well-executed.

Aptosuser

And this is why I did not become an engineer!

kitlz

Well, I do call my 450h Urkel, LOL!

TechNut

Let me share a different angle on this thread. We purchased an RX 350 and if price were no object, I would have definitely gone with the 450. Unfortunately for me, I really like the new car experience and adding the hybrid to all the other goodies I wanted just pushed the price too high for me. So I had to settle for either a new 350, or a used 450. I don't feel like I "settled" for anything by the way since I love the 350. (Perhaps it's better not to know what you are missing?)

For me, there were also some other reasons. Our daily driver is a Prius, so we get to enjoy the cool tech on another vehicle (I too am a tech geek and work in IT). Since we use the Prius for our daily commuter, we don't put very many miles on the RX annually so the ROI really wasn't there for us. I realize that is a very clinical perspective and doesn't account for the smoother transmission or quieter operation, but that was our rationale. The RX can often sit for a week, sometimes two, and I have learned from two different Priuses that the hybrid functions better when driven more regularly. It seems to take the batteries a couple of days after a vacation to get back to normal operation. We just weren't sure we needed two hybrid vehicles.

More of our RX miles are also highway miles, where the advantage isn't as great.

So I would never argue against a 450, but for our needs and expectations (based mostly on our budget as well as our daily commuter car) the 350 was just a better fit.

Doug (a 350 owner spying in a 450 thread....)

Aptosuser

Doug, it sounds like you made a very sensible decision. I agree that your return on investment from a 450h would not have been favorable enough to justify the extra cost. In our case, we really liked the 2012 Camry hybrid XLE we got for my wife -- new -- to replace the 2001 Volvo S70 she'd been driving. She loved the way the car drove and rode and I loved the hybrid technology. I was driving an '07 RAV4 Limited (also purchased new). It was a 4WD, six-cylinder, 5-speed automatic, and I really liked the way it drove (especially having all the power when I needed it). I also liked having the versatility of a small SUV and because I have a bum hip, sitting higher. But after 6 1/2 years of driving the RAV (it still had less than 50,000 miles on it), I'd come to dislike its hard ride, and my wife hated it. Also the leather seats were less than comfortable. They were very hard initially and it took a couple of years of butt time for the driver's seat to soften. Even then, it was still too shallow for my 5' 11" frame (I've been shrinking with age; I'd lost an inch in height since I bought it). So I wanted to upgrade to a better-riding, more comfortable car and I was already lusting for a hybrid crossover.

Through a Google search, I learned that Lexus would be coming out with a new, smaller SUV just a bit larger than my RAV4, in gas and hybrid versions -- the NX, which will reportedly be unveiled at an auto show in Beijing later this year. I figured it would come on the market at a more affordable price than the 450h, plus it would get better mileage. And I figured that it would be way more comfortable than the RAV (my wife called it "the RAT"). But out of curiosity, I started watching area car dealers' Web sites to see what was around in the way of recent-vintage 450h's. I lucked out and found this one-owner, certified 2010 at a Lexus dealer in Monterey with just under 15,000 miles on it and already priced below what KBB said was a good price for a used car (excuse me, "pre-owned") with as few miles on it and in mint condition, which is the only kind of certified Lexus(es) dealers sell.

So we got this car "like-new", but well below what it cost new. It drives like a dream and we both love it. My wife has been chauffeuring me around in it lately because I have a medical situation that precludes me from driving. It's been pretty much all highway miles at 100 miles round trip at a crack between our house south of Santa Cruz and Stanford, where my doctors are. She's averaged more than 31 mpg, according to the car's computer which I think overstates mpg by a mile or two. But still, I gotta drive more like she does -- a few mph slower -- so's I can match her.

I'd bought a couple of "used" Volvo sedans that had been in rental fleets and hardly driven with only 12,000 miles on them. "Like new" again. So I had no hesitation about buying this RXh. There wasn't another certified 2010 hybrid within 100 miles with that little mileage, plus all the others were priced the same or more. It was just too good an opportunity to pass up. Plus it was the proverbial bird in hand vs. the still unseen NX in the bush. However nice the NX turns out to be, we won't be looking back.

websailor

LOL, it is such an easy decision for me in regards to our alternative rides! If I'm not driving the RX450h, then I'm driving my 1996 Toyota Tacoma truck.

If there is an opposite to the very electronic 450h, this is it! You manually crank the windows up or down, has manual door locks, you use the clutch to put it into different gears, it has a great little 4 cylinder engine to get it up to highway speeds, a wonderful AC on/off button, one long bench seat made of rough cloth fabric (it is manually adjustable), and you are not distracted by any fancy gizmos such as a clock!

Lately since we got the RX450h, it has not been driven very much. I do have to say that if I have to rebuild a fence, I'd much rather put the messy bags of cement into the Tacoma.