"Get a hold of the engineers at Lexus and tell them you want your RX400h built using the Atkinson cycle. That you are going after the world record mileage in an SUV. You got stroke there at Lexus with all the cars you have bought."
I rather doubt that Lexus is willing to put in the development time and testing of the computer code required to provide such an engine. They cannot simply re-use the Prius code; it is a different engine.
Dave Hermance, executive engineer of environmental engineering at Toyota’s Technical Center, said performance, not fuel economy, was the goal with the RX400h system.
How would you interpret the above statement by Toyota? If they can get 37 MPG as some have claimed with the high performance, why is 45 MPG out of reach?
As Larsb stated, it is amazing that everyone that hears hybrid, thinks it means outrageous gas mileage. I think it's pretty darn amazing that you have a 4500 vehicle that can easily get an average of 27 MPG. Ironically, the GM SUVs (Envoy, Trailblazer) can barely get above 14 MPG avg. This is truly a triumph. I suppose that Toyota could have used the Atkinson cycle but at the expense of performance.
Nonhybrid: 242 lb-ft at 3600 rpm 230 hp at 5600 rpm
The engine is definitely changed for hybrid application. I believe toyota made a calculated statement of avoiding the word atkinson in order not to associate with the prius having slow acceleration.
This is from www.technorocket.com/forums/showthread.php?threadid=278&goto=newpost
"As a "full hybrid" the RX400h is capable of running solely on its electric motors, solely on its 3.3-liter V-6, or with the electric and internal combustion systems working in tandem. The DOHC, 24-valve V-6 is the same basic 3MZ-FE engine installed in the RX330 (and the ES330, Toyota Sienna, Solara, Highlander and some Camrys) without an alternator and with the power steering pump, water pump, and A/C compressor removed to be driven electrically. Despite that reduction in parasitic drag, revised calibration of the VVT-i variable valve timing and electronic throttle limit engine output to 208 horsepower at 5600 rpm and 212 pound-feet of peak torque at 4400 rpm compared to the RX330's 230 hp at 5600 rpm and 242 lb-ft at 3600 rpm. The lower output, claims Lexus, is "to promote smooth integration with hybrid system" which includes a unique electronically controlled continuously variable transmission (CVT) instead of the five-speed automatic transaxle to which the 3.3-liter is leashed in all its other U.S. applications."
Madison Hybrid Group is still looking for at least one 400h owner to join our July 17th Hybrid Car Event at Miller Park in Milwaukee.
So far the Escape, Accord, Civic, Insight, Prius, and Highlander will be represented.
***But we still need a 400h owner to come and represent your hybrid!!!****
We would love to have you come. Please contact me ASAP if you are interested in coming. The “official” deadline for buying tickets has passed, but we can still squeeze you in.
Details of the event.
Sunday July 17, 2005 Milwaukee, WI
Madison Hybrid Group invites you to attend our 2nd Annual Miller Park Hybrid Car Event!
Have fun meeting, tailgating and talking with hybrid car owners. Ask questions, find answers, show off your car, and, oh, yeah, watch the Brewers take on the Washington D.C. Nationals.
Schedule of Events 10:00-11:00 Meet at the pre-staging area in Wauwatosa (Same place as last year. Click on this link to create directions. http://tinyurl.com/7eywa ) 11:00 Leave the staging area as a group and take a short drive to Miller Park. 11:15 Enter the “Giants“ Parking Lot as a group. ($6 per vehicle.) 11:15-1:00 Tailgate until game time. Food, conversation and fun. 1:05 Game Time
Cost: $10 per ticket which includes -One Terrace Reserved seat in our Group's block of seats -One FREE hot dog -One FREE soda -One entry into our drawing for two FREE tickets to a Monday-Thursday game. (Non-Cubs)
To attend, please respond via this thread, or email me at MadisonHybridGroup at gmail dot com and I’ll send you the address for mailing payment.
I for one would never have bought a 400h if it was gutless. I even doubt I would have been too interested if its 0-60 was a second slower than the regular 330. My intense interest in this car is based on it being a premium ride with V8 power and subcompact fuel economy.
You can actually get a better ride in the standard RX330 as it has the air suspension option not available in the RH. I've driven both and can't really tell the difference (didn't try the one with the air). I did notice that when the engine does come alive, it is a little less subtle than the Prius. You definitely do get great fuel economy, but you are paying nearly 10 grand more for that benefit. As far as performance gains, they're marginal at best. Less than a second from 0-60?? Not sure...
My RX300 is far from gutless, and the RX330 has a bigger engine and even more HP/Torque. The current RX400h uses batteries and A/C motors to "convert" a detuned (208HP) 3.3L V6 to the level of V8 performance. So I have absolutely no doubt that further detuning of the ICE using the atkinson cycle would yeild a substantial improvement in fuel economy and at the same time give us a level of performance at least equal to the RX330 if not better.
People pay this kind of premium ALL THE TIME for minor increases in performance. BMW 330 vs. M3... Mercedes ML320 vs. 430 (or whatever it's called these days)... There are at least a couple dozen examples in production today....
And the premium is nowhere near $10K when you factor out the equipment benefits. Even including the discounts on the RX300 -- an arbitrary inclusion to me, but whatever -- you are looking at around $5-6K in actual price difference for comparable equipment.
Figure on something like 200 gallons per year of gas savings at, say $2.25 over the next four years and you have saved well over half the difference. Figure on the greater resale value mitigating another "half" of the difference after that.
The 4-year TCO of the hybrid is barely anymore than the RX330. But the peace of mind of doing something about America's pathetic energy situation, the greenhouse effect, etc. while getting a quieter car that also outperforms the RX330 is easily worth a couple grand to myself and probably every other 400h owner.
I agree with you 100%. If I needed that type of vehicle, I would want the hybrid. Right now they are charging full list for them (50k). I can easily get a nicely optioned 330 for 40k. I am merely saying that it does not make economic sense for certain people to buy the RH solely to expect fuel savings to make up the premium. The people who should be buying at are the ones you mentioned. It definitely makes a statement and manufacturers are taking notice.
"Assuming you are correct how is it then possible for the Millenia S to couple the atkinson cycle with the burden of driving a Supercharger (now becomes "Miller" cycle) and yet still yield a ~20% improvement in fuel economy?"
As I understand the Miller cycle, they are taking advantage the fact that positive displacement superchargers are actually MORE efficient than piston engines at doing compression work at low pressures. By closing the intake valve later, the piston does not do the first 20% of the compression work, that is done by the supercharger in the form of forced induction. Expansion ratio is about 10:1, compression ratio 8:1. Not really a high expansion engine like the Prius at 13:1, or the Ford Escape Hybrid at 12.3:1.
Also, the number I have seen for efficiency gain of the miller is 10-15%.
I tried to beat cyclone's number, but I couldn't. I came close enough to verify it though. For 27 miles of city driving, in conditions from stop and go to 45mph, I got 38.9 MPG. I started with the engine warm, and it was hot out, 88 deg. I did not use AC, but had the windows open. No special driving techniques other than being smooth, I was accelerating with the light to medium traffic for the most part. There were plenty of hills up and down, but no net altitude gain or loss. Net battery consumption was 2 bars, so by my previous calculation, knock about 2MPG off the number. Average speed was 15 or 20mph, including stops. I get a sense the car can do better, and I will take another run at it when I get a chance.
Unfortunately for my mileage, I have started to really enjoy the power of this car. It pulls like a mule, you can really feel all four wheels putting down the torque, especially on uneven road surfaces. The power meter pegs at 200kW for a nice large range of speeds, from 20mph or so on up to 90mph at least, I haven't probed past there. The lag when you get on from a standstill it is a little annoying, but once you get rolling it is great, no shifts! I find that at a standstill, with my left foot on the brake, I can give it a little throttle and get the engine started to reduce the lag at launch.
How many cars let you experiment with 40MPG one day, and techniques to smoke unsuspecting sports cars the next, all in spacious comfort.
re: Full list for 400h (50k) vs. nicely optioned 330 (40K)
I thought about the same thing, but here are some issues to consider:
1. 400h comes as standard with nav+rear camera, swing headlights, 4WD. Those options on the 330 would push the price well above $40k. So in effect, they loaded up the 400h base, as compared to the 330.
2. Tax credit $2k (? check with your accountant). This is straight tax reduction, not a deduction of taxable income. So if you're at 33% tax bracket, this $2k tax credit is equivalent to $6k of taxable income: subtract $6k from the price!
3. Performance wise: I've used Continuous-Variable Xmission for so long that I can not stand the regular Xmission's momentary loss of drive (quarter to half of a second) when it tries to decide which gear, up or down, to shift to. It's when you slow down to turn the corner and accelerate after the turn.
4. Yes, the torque you experience from a stop: immediate, and powerful enough to get you out of trouble quickly.
And the much heralded fuel saving amounts to about $900-$1000k per year for me, so it takes some times to break even, depending on how you estimate it.
The numbers make sense for me vs. the performance I'd get.
If you detune the engine to say dedicated atkinson setting, I would guess the best mileage you can get maybe similar or slightly less to that of Escape hybrid. However, I would suspect the acceleration will be prius-like. No sources, just a speculation.
2. Tax credit $2k (? check with your accountant). This is straight tax reduction, not a deduction of taxable income. So if you're at 33% tax bracket, this $2k tax credit is equivalent to $6k of taxable income: subtract $6k from the price!
It is a $2000 tax deduction not credit. If you are in the 33% bracket it will save you $660 on your tax bill.
An RX330 in San Diego with NAV, rear camera, Mark Levinson, Moonroof, HID & bluethooth is $41,283
The ICE in the RX400h is already detuned down to 208HP and the ICE + electrics still yeilds V8 "class" HP/Torque. I think the combination is rated at 268HP but I have never seen an overall torque rating. I suspect that's because the A/C motors are VERY high torque at startup and then the torque drops off substantially as the RPMs rise.
Additionally the way the documents read the rear motor is never fully untilized unless wheelslip/spin is encountered at the front. Otherwise the rear motor is used only during initial acceleration from a stop, as you enter a turn, and of course at WOT.
So I suspect that the use of the atkinson cycle will result in only backing down to the level of the RX330 insofar as HP/torque is concerned. Also remember that the duration that the intake valve remains open during the compression stroke is totally MY choice.
30% might be ideal but as little as 10% might still yeild a substantial level of additional fiel economy.
You have to get the baseline camsetting first. You may decipher the intake cam setting manually and find out at what degree does the intake close. Pull out one spark plug, plug in a compression/pressure meter, and turn the crak manually until the meter spikes and take note of the crankshaft roatation.
You have to take into consideration that this is vvt-i and the timing of closure can vary at different engine speed and load dictated by the ECU.
From the peak torque point of view, it looks like it is already semi-atkinson because the peak torque is now at 4400 rpm compared to 3600 and the peak torque number is signifiacntly lower than the non-hybrid. It would indicate that at lower RPM the torque will be even lower.
Way to go Dylan! I am also of the opinion that one can even do better than 40 mpg with a little more effort.
I know exactly what you mean about having a hard time choosing between getting great gas mileage and utilizing its power which is fantastic. For example, I really enjoy getting into entrance ramps for the intersate and stepping on it. Man, it reaches 80mph in no time. Those behind me must be really wondering, "how can he accelerate like that with an SUV"? And in passing situations, it takes off "like a rocket". The drivers I pass must be really impressed.
It was plenty fast when my friend and I test drove it. Only thing is that the handling is not that great (but neither is any SUV). I don't think you'll impress anyone in an FX45 though. That SUV is pretty quick!!!!
I have 550 miles on my 400h and am using premium unleaded gasoline (Octane rating of 91). After a break in period of 1,599 miles I am considering trying regular unleaded (Octane rating of 87) like I used in my Rx300.
The owner's manual says that any gas below 91 octane will cause "persistent heavy knocking."
Is anyone using gas below 91 octane? If yes, is there a drop off in performance and or mpg?
I never knew that you had to use premium fuel in the RH. With today's onboard computers which can retard timing, I doubt the engine would knock. Try it and see what happens. I used to use regular in my RX too. My friend has an Audi A4 and uses regular with no problems.
Didn't they also drop the dual volume intake manifold?
If so that might account for the peak torque shift.
What do you think about simply miss-timing the existing intake cams?
Just shift the cam timing for the intake valves so they open late on the intake cycle and then remain open for the early portion of the compression cycle.
The RX400h takes 87 (minimum) octane. It says so on the Owner's Manual. We have been filling it up with 89 octane ethanol because here we live 10% ethanol blend is 10 cents per gallon cheaper than regular unleaded (87 octane). The car runs great. When we toook a long trip to Dayoton, OH, then to Detroit, and back home in late May and early June we filled it up with 87 octane (ethanol was not available in these other states) and had not problem whatsoever.
"Didn't they also drop the dual volume intake manifold? If so that might account for the peak torque shift. "
I agree, the hybrid inhales less air per cycle at lower RPM partly due to the absence of the ram effect of the long intake runners. But I think the other factor is reprofiled intake cam.
"What do you think about simply miss-timing the existing intake cams? Just shift the cam timing for the intake valves so they open late on the intake cycle and then remain open for the early portion of the compression cycle. On the cheap trial."
I think in the dual intake cam of the vvt-i, only one of them is variable, the other is fixed. The degree of the variation on the first cam provides the resultant opening span. Taking this into account, the setting is capable of atkinson (late intake closure).
However, toyota opted to retain power so the logical choice would be to adjust the inake setting close to otto cycle at higher RPM.
The result is excellent efficiency at low horsepower production necessary for steady speed plus the retention of power at higher RPM.
I would imagine that to have a fixed atkinson all throughout the rev range would require the RX400H to over-rev at the slightest hint of acceleration just to comply with the hp requirement. But that can also be taken cared off by the battery.
However, if the battery is out of charge, you will end up with a noisy buzzing engine.
87 octane for 1200 miles and no knocking noticed. We haven't tried anything else so we have nothing to compare it to though. We love this car and we're getting great mileage. We especially agree with everyone else regarding the ZIP factor. Like cyclone4, we're at 80mph before we realize it. Our freeway onramp is an uphill-er and it's fun to fly onto it.
Glad to hear you're enjoying the "zip" you're getting with the RX400h! I find it amazing that you can have near V8 level performance and still achieve compact car mileage with such a heavy comfortable vehicle. Lexus/Toyota continues to amaze me with their innovative engineering.
My wife and I will be out of town for a week. Does anyone know if the 400h battery will die if it is not driven for a week? I would hate to come home and find a dead battery.
$41,283 is the AWD price for the RX330. I am not sure what you mean by deduction. You get to reduce your adjusted gross income by $2000. If you are in the 33% bracket you will save $660. Not like a tax credit where it reduces your tax bill. Only Electric and alternate fuel vehicles qualify for the maximum $4000 tax credit.
Below is an interesting article about hybrid technology. Lexus states that the RX400h is a parallel hybrid. The "Full Hybrid" section of this article better defines what the 400h delivers.
Well, after having my 400h since April 18th, it is now in the shop for it's first repair. :sick: I was on vacation for 9 days and started my lexus only to see an unfamiliar message on the nav screen. "System loading, do not turn off power". Well this stayed on for 30 minutes then I gave up and turned the motor off. It seemed okay to drive and I'm hoping it just had to do with the nav maps. I'll let you know how it turns out, but if anyone else has had this problem, please let me know.
Well news from the service department. The hard drive for the Nav system failed. It is the second one they have seen on a 400h at that dealership, and is starting to be listed as a "known problem". It has to stay the night and will hopefully be ready tomorrow (they have to overnight the part). The were out of Lexus loaners, so I'm stuck with a Mustang for now.
In steamy South Florida a moonroof is a waste of money. Given the choice I would never have wasted mine on it. All due respect, if you want light coming in and wind in your hair, buy a convertible!
i believe the air-ride option was only available in the 2004rx. in the normal mode, the ride is the same. in low mode, the ride is a little stiffer but handling is improved. it's great for when there's heavy crosswinds or going up/down mountains (less sway). i'm still debating whether i want to keep my 04rx or upgrade to hybrid. if ride-ride was an option for the hybrid, that would be my definition of a perfect car.
My local Lexus dealer has two RX 400H's on the used car lot. The story is that each was driven by local high profile individuals who get new cars every two to three months. Each has about 1600 miles on it. Is the engine break in more important for a hybird that for other cars? I doubt that either was given a great deal of TLC. Would this be something to consider? Or would you recommend I stay away?
There is a few months of undesirable weather in FL. It's the summer months. In the north, it's the winter months. On the other hand, there's 8-9months of pretty good weather for a moon roof, or in FL we should call it sunroof.
I've used Zaino waxing products for years now, and can testify to its awesome effect. If you'd like to try it, go to www.zainobros.com for a look.
It is expensive, but it is better than anything I had tried. You'd get the awesome "wet" look on your car. You just wipe the solution on your car, wait 'til it dries off, then simply wipe it off with a clean white cloth (no need for power buffing, no worn out muscles).
If you wax it repeatedly 3-5 times, you'd get a nice and thick layer on your car. It lasts a very long time as long as you dont wash your car with a strong detergent.
Check it out. It will enhance the "new" look on your rx400h. Note that darker colors would always look better.
If 10% ethanol has 3.5% less energy than straight gasoline, is it appropriate to correct MPG numbers for comparison? It doesn't sound like much, but it makes 24.9 mpg onto 25.8mpg.
My 400h was only giving me about 21 mpg around town, so today I turned off the AC and really babied it for about 20 miles of stoplights and back roads. Amazingly, it averaged 33.4 for the trip! It's hard to believe, but driving technique alone raised the mpg by more than 50%! The highway mileage has been about 28 with AC and 87 octane. I let my father drive it around on Father's Day, and he was completely astonished at the acceleration. What an incredible vehicle...
i love zaino too!! my husband thought when i decided to try it that i had bought something gimmicky like as seen on tv stuff but now he loves it too!! newcomers may find it intimidating at first because of the multiple steps but it's all simple put-it-on, wipe (not buff!!) off. it lasts a long time too. after 9 months of nonwaxing, my husband's car still shined after washing and water was still beading decently! (we only did 3 coats so not that much to wear off) definitely something to try if you're tired of having sore arms after traditional waxing.
*warning: washing and waxing may become addictive after discovering these products*
We recently returned to our RX400H from a two week trip abroad. Of course when I went out to drive it, I wasn't thinking so the first thing I did was to operate the power back door. (The owner's manual recommends that you not use the power back door before starting the car.) Fortunately, the RX400 started just fine. I expect the power back door warning is too cover the loss of capacity the auxiliary (12 V) battery will have over the course of its service.
The manual suggests disconnecting the aux battery if you will leave the car sit for a month, I think.
"(The owner's manual recommends that you not use the power back door before starting the car.) "
That should have been: (The owner's manual recommends that you not use the power back door before starting the car after leaving the car undriven for two weeks.)
Apparently the industry is struggling to figure out how to keep the catalyst above or near its 750F optimum operating temperature in hybrid systems. According to the patent the ICE even needs to be operating under a significant load level in order for the exhaust gasses to retain enough energy to maintain the catalyst at the optimum operating temperature level.
So:
No atkinson cycle.
And the engine must be run UNDER LOAD in order for the exhaust gasses to be HOT enough to keep the catalyst LIT-OFF.
Absent using the energy recovered via regenerative braking to keep the catalyst lit-off, as proposed in the above referenced patent.
Comments
I rather doubt that Lexus is willing to put in the development time and testing of the computer code required to provide such an engine. They cannot simply re-use the Prius code; it is a different engine.
How would you interpret the above statement by Toyota? If they can get 37 MPG as some have claimed with the high performance, why is 45 MPG out of reach?
Hybrid:
212 lb-ft at 4400 rpm
208 hp at 5600 rpm
Nonhybrid:
242 lb-ft at 3600 rpm
230 hp at 5600 rpm
The engine is definitely changed for hybrid application. I believe toyota made a calculated statement of avoiding the word atkinson in order not to associate with the prius having slow acceleration.
This is from www.technorocket.com/forums/showthread.php?threadid=278&goto=newpost
"As a "full hybrid" the RX400h is capable of running solely on its electric motors, solely on its 3.3-liter V-6, or with the electric and internal combustion systems working in tandem. The DOHC, 24-valve V-6 is the same basic 3MZ-FE engine installed in the RX330 (and the ES330, Toyota Sienna, Solara, Highlander and some Camrys) without an alternator and with the power steering pump, water pump, and A/C compressor removed to be driven electrically. Despite that reduction in parasitic drag, revised calibration of the VVT-i variable valve timing and electronic throttle limit engine output to 208 horsepower at 5600 rpm and 212 pound-feet of peak torque at 4400 rpm compared to the RX330's 230 hp at 5600 rpm and 242 lb-ft at 3600 rpm. The lower output, claims Lexus, is "to promote smooth integration with hybrid system" which includes a unique electronically controlled continuously variable transmission (CVT) instead of the five-speed automatic transaxle to which the 3.3-liter is leashed in all its other U.S. applications."
So far the Escape, Accord, Civic, Insight, Prius, and Highlander will be represented.
***But we still need a 400h owner to come and represent your hybrid!!!****
We would love to have you come. Please contact me ASAP if you are interested in coming. The “official” deadline for buying tickets has passed, but we can still squeeze you in.
Details of the event.
Sunday July 17, 2005
Milwaukee, WI
Madison Hybrid Group invites you to attend
our 2nd Annual Miller Park Hybrid Car Event!
Have fun meeting, tailgating and talking with hybrid car owners. Ask questions, find answers, show off your car, and, oh, yeah, watch the Brewers take on the Washington D.C. Nationals.
Schedule of Events
10:00-11:00 Meet at the pre-staging area in Wauwatosa
(Same place as last year. Click on this link to create directions. http://tinyurl.com/7eywa )
11:00 Leave the staging area as a group and take a short drive to Miller Park.
11:15 Enter the “Giants“ Parking Lot as a group. ($6 per vehicle.)
11:15-1:00 Tailgate until game time. Food, conversation and fun.
1:05 Game Time
Cost: $10 per ticket which includes
-One Terrace Reserved seat in our Group's block of seats
-One FREE hot dog
-One FREE soda
-One entry into our drawing for two FREE tickets to a Monday-Thursday
game. (Non-Cubs)
To attend, please respond via this thread, or email me at
MadisonHybridGroup at gmail dot com and I’ll send you the address for mailing payment.
Eric Powers
Madison Hybrid Group
And the premium is nowhere near $10K when you factor out the equipment benefits. Even including the discounts on the RX300 -- an arbitrary inclusion to me, but whatever -- you are looking at around $5-6K in actual price difference for comparable equipment.
Figure on something like 200 gallons per year of gas savings at, say $2.25 over the next four years and you have saved well over half the difference. Figure on the greater resale value mitigating another "half" of the difference after that.
The 4-year TCO of the hybrid is barely anymore than the RX330. But the peace of mind of doing something about America's pathetic energy situation, the greenhouse effect, etc. while getting a quieter car that also outperforms the RX330 is easily worth a couple grand to myself and probably every other 400h owner.
As I understand the Miller cycle, they are taking advantage the fact that positive displacement superchargers are actually MORE efficient than piston engines at doing compression work at low pressures. By closing the intake valve later, the piston does not do the first 20% of the compression work, that is done by the supercharger in the form of forced induction. Expansion ratio is about 10:1, compression ratio 8:1. Not really a high expansion engine like the Prius at 13:1, or the Ford Escape Hybrid at 12.3:1.
Also, the number I have seen for efficiency gain of the miller is 10-15%.
Unfortunately for my mileage, I have started to really enjoy the power of this car. It pulls like a mule, you can really feel all four wheels putting down the torque, especially on uneven road surfaces. The power meter pegs at 200kW for a nice large range of speeds, from 20mph or so on up to 90mph at least, I haven't probed past there. The lag when you get on from a standstill it is a little annoying, but once you get rolling it is great, no shifts! I find that at a standstill, with my left foot on the brake, I can give it a little throttle and get the engine started to reduce the lag at launch.
How many cars let you experiment with 40MPG one day, and techniques to smoke unsuspecting sports cars the next, all in spacious comfort.
I thought about the same thing, but here are some issues to consider:
1. 400h comes as standard with nav+rear camera, swing headlights, 4WD. Those options on the 330 would push the price well above $40k. So in effect, they loaded up the 400h base, as compared to the 330.
2. Tax credit $2k (? check with your accountant). This is straight tax reduction, not a deduction of taxable income. So if you're at 33% tax bracket, this $2k tax credit is equivalent to $6k of taxable income: subtract $6k from the price!
3. Performance wise: I've used Continuous-Variable Xmission for so long that I can not stand the regular Xmission's momentary loss of drive (quarter to half of a second) when it tries to decide which gear, up or down, to shift to. It's when you slow down to turn the corner and accelerate after the turn.
4. Yes, the torque you experience from a stop: immediate, and powerful enough to get you out of trouble quickly.
And the much heralded fuel saving amounts to about $900-$1000k per year for me, so it takes some times to break even, depending on how you estimate it.
The numbers make sense for me vs. the performance I'd get.
Cheers.
It is a $2000 tax deduction not credit. If you are in the 33% bracket it will save you $660 on your tax bill.
An RX330 in San Diego with NAV, rear camera, Mark Levinson, Moonroof, HID & bluethooth is $41,283
No, I am not an engineer and never claimed to be one.
Please, let's close the "engineer" part of the discussion and move on.
Additionally the way the documents read the rear motor is never fully untilized unless wheelslip/spin is encountered at the front. Otherwise the rear motor is used only during initial acceleration from a stop, as you enter a turn, and of course at WOT.
So I suspect that the use of the atkinson cycle will result in only backing down to the level of the RX330 insofar as HP/torque is concerned. Also remember that the duration that the intake valve remains open during the compression stroke is totally MY choice.
30% might be ideal but as little as 10% might still yeild a substantial level of additional fiel economy.
You have to take into consideration that this is vvt-i and the timing of closure can vary at different engine speed and load dictated by the ECU.
From the peak torque point of view, it looks like it is already semi-atkinson because the peak torque is now at 4400 rpm compared to 3600 and the peak torque number is signifiacntly lower than the non-hybrid. It would indicate that at lower RPM the torque will be even lower.
Good luck.
I know exactly what you mean about having a hard time choosing between getting great gas mileage and utilizing its power which is fantastic. For example, I really enjoy getting into entrance ramps for the intersate and stepping on it. Man, it reaches 80mph in no time. Those behind me must be really wondering, "how can he accelerate like that with an SUV"? And in passing situations, it takes off "like a rocket". The drivers I pass must be really impressed.
The owner's manual says that any gas below 91 octane will cause "persistent heavy knocking."
Is anyone using gas below 91 octane? If yes, is there a drop off in performance and or mpg?
How about the persistent knocking warning?
If so that might account for the peak torque shift.
What do you think about simply miss-timing the existing intake cams?
Just shift the cam timing for the intake valves so they open late on the intake cycle and then remain open for the early portion of the compression cycle.
On the cheap trial.
If so that might account for the peak torque shift. "
I agree, the hybrid inhales less air per cycle at lower RPM partly due to the absence of the ram effect of the long intake runners. But I think the other factor is reprofiled intake cam.
"What do you think about simply miss-timing the existing intake cams?
Just shift the cam timing for the intake valves so they open late on the intake cycle and then remain open for the early portion of the compression cycle.
On the cheap trial."
I think in the dual intake cam of the vvt-i, only one of them is variable, the other is fixed. The degree of the variation on the first cam provides the resultant opening span. Taking this into account, the setting is capable of atkinson (late intake closure).
However, toyota opted to retain power so the logical choice would be to adjust the inake setting close to otto cycle at higher RPM.
The result is excellent efficiency at low horsepower production necessary for steady speed plus the retention of power at higher RPM.
I would imagine that to have a fixed atkinson all throughout the rev range would require the RX400H to over-rev at the slightest hint of acceleration just to comply with the hp requirement. But that can also be taken cared off by the battery.
However, if the battery is out of charge, you will end up with a noisy buzzing engine.
You're right. it is a tax deduction, which effectively means $2000 off of the price.
re: An RX330 in San Diego with NAV, rear camera, Mark Levinson, Moonroof, HID & bluethooth is $41,283
Have you checked the all wheel drive price?
$41,283 is the AWD price for the RX330. I am not sure what you mean by deduction. You get to reduce your adjusted gross income by $2000. If you are in the 33% bracket you will save $660. Not like a tax credit where it reduces your tax bill. Only Electric and alternate fuel vehicles qualify for the maximum $4000 tax credit.
A week? No problem. If it were 3 weeks, there might be some cause for concern, but yours should be fine.
http://www.earthtoys.com/emagazine.php?issue_number=05.06.01&article=naftc
It is expensive, but it is better than anything I had tried. You'd get the awesome "wet" look on your car. You just wipe the solution on your car, wait 'til it dries off, then simply wipe it off with a clean white cloth (no need for power buffing, no worn out muscles).
If you wax it repeatedly 3-5 times, you'd get a nice and thick layer on your car. It lasts a very long time as long as you dont wash your car with a strong detergent.
Check it out. It will enhance the "new" look on your rx400h. Note that darker colors would always look better.
Amazed in Arlington, VA
*warning: washing and waxing may become addictive after discovering these products*
The manual suggests disconnecting the aux battery if you will leave the car sit for a month, I think.
You should be just fine.
That should have been:
(The owner's manual recommends that you not use the power back door before starting the car after leaving the car undriven for two weeks.)
Apparently the industry is struggling to figure out how to keep the catalyst above or near its 750F optimum operating temperature in hybrid systems. According to the patent the ICE even needs to be operating under a significant load level in order for the exhaust gasses to retain enough energy to maintain the catalyst at the optimum operating temperature level.
So:
No atkinson cycle.
And the engine must be run UNDER LOAD in order for the exhaust gasses to be HOT enough to keep the catalyst LIT-OFF.
Absent using the energy recovered via regenerative braking to keep the catalyst lit-off, as proposed in the above referenced patent.