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Toyota Prius, Hybrid Cars, Car Buying, Hatchback, Sedan
#136 of 311 Re: 1.8L Upgrade for 2009 ?? [pathstar1]
Feb 05, 2008 (5:27 am)
I looked up the engine specs for bore and stroke for the 2007 Camry unchanged with the Atkinson variant. The 2.4L 2AZ-FXE engine has a longer stroke (96mm) than the Prius 1.5L (84.7mm). Furthermore the Camry's 6000rpm yields an astounding average piston speed of 19.2m/sec - that's close to racing engine territory.So your statement Long stroke engines don't handle high RPM well may be good theory but Toyota doesn't appear to be following it. In comparison the 1NZ-FXE engine in the Prius tops out at at a leisurely 13.55m/sec piston speed at 5000rpm.
I have to defer to your grasp of available engines. The 1.6L would work as an upgrade and in keeping with production conformity. I am not familiar with this engine. The HSD will of course just throttle back a more powerful engine to prevent torque overload on MG1. If this engine suited the 6000rpm mod that I outlined earlier - then fine. As a marketing ploy I am not sure this upgrade is a good idea.
My take is to go the other way with the adoption of a 1.0L 3 cyl similar to the Honda Insight engine. This would yield a big step in fuel economy for the careful driver. On the other hand aggressive driving would showcase the superiority of the HSD system particularly with smaller engines. If you remember, the original cars were fairly anaemic with the same 1NZ-FE engine. It was the 50 % upgrading of the power electronics for the 2004 model year that transformed this car and I am of the opinion that this fact alone will mask somewhat the adoption of a less powerful engine. Going to a tad lighter powertrain up front may affect positively the handling performance also.
#137 of 311 ICE RPM limit.
Feb 05, 2008 (9:33 am)
Might be a function of the torque/RPM limits of the AC synchronous motor on the opposite end of the CVT. If the ICE, at top RPM, produces 120 ft/lbs of torque then the AC motor must produce 40 ft/lbs at 3 times the ICE's RPM (assuming a 1:3 reduction ratio).
And my suggestion of a variable speed SC had to do with lowering the size of the ICE while producting the same level of torque and at the same time "evening out" the torque curve, raising the ICE torque at the low end.
There is also the additional issue with the SC boost available of not having to put the electrics to so much use for hwy use when it cannot be recharged except via the ICE.
#138 of 311 Re: ICE RPM limit. [wwest]
Feb 05, 2008 (6:03 pm)
I am going to respond as best I can.
I have to make a correction regarding your first paragraph. The torque of the ICE at 5000rpm is around 82lbs-ft not 120lbs-ft, that's if we are discussing the Prius that is. As you are no doubt aware the PSD is not accurately a Power Split Device as Toyota likes to describe it but actually a Torque Split Device. It's a trap I fell into a few years ago since those mathematical equations are a bore. To continue then, we have the PSD splitting the engine torque sending 1/3.6 times 82 or 22lbs-ft into MG1 and the remaining 2.6/3.6 times 82 or 59lbs-ft to the ring gear and ultimately the wheels which I am sure you know.Those figures are reached during maximum acceleration. However as I understand it, as a generator there is no limitation on MG1 except with the proviso that you don't let it generate more than 100 amps or exceed 10,000rpm else the ECU will cause the ICE to be throttled back On the Camry they've allowed a version of this machine to reach 14,000 rpm. So I am confident there is not an rpm issue with MG1 that correspondingly limits the ICE rpm. And MG1 is the critical machine in the HSD system.
Regarding your middle paragraph, I wasn't aware there was a bottom end torque deficiency but I'm taking your word for it. All I know is that those with scan tools said that Toyota likes to 'park' the engine at 1211 rpm when they need to keep it running when power demand is less than about 8 Hp. If torque was linear then at 1/4 speed as here we should expect 76/4 or 19Hp at this speed so that indeed corroborates what your stating. Naturally the longer you can keep the engine at these low revs the better the fuel economy -reduced engine frictional losses etc.
I don't get your last paragraph since the SC is not going to help during acceleration since the engine will move up its speed range quite quickly thanks to the partial decoupling of the engine from the wheels afforded by the HSD system.
Toyota may be addressing low speed torque deficiency with its double VVT-i engine at the next upgrade.
#139 of 311 '09 PRIUS = A Cross Between Tesla & Lexus?
Feb 18, 2008 (12:26 pm)
Alright, a slight exageration but still a very interesting thought. I can't help but feel the 2ND Generation Prius has ran its' unchanged body style to its' limits but I find it to be a valid testimony to what a great and functional style it has been. My '04 has kept up with the last 5 yrs of styles and weathered the trends well. Still. I would like to see a sleeker, somewhat sportier Prius with a sunroof. Could a hardtop convertable be asking too much? (probably too pricy)
As to some of the complaints of others about the seats. I've done several trips (2,000 miles plus) and found them to be more than comfortable. The car will never ride like a "Towncar" but reasonable people know this. A few things I'd like to see on the '09 Prius...SmartKey standard....Tiltwheel...Wider Tires... and (what I hope is coming) THE PLUG-IN Mode. Oh! By the way ...I hope Toyota improves the ease of replacing Hd Lt Bulbs. They're a %*#!!!!
Feb 21, 2008 (12:40 pm)
Is Toyota really going to have a 3rd gen Prius on the market that soon? If you mean model year 2009, that is only months away...If you mean calendar year 2009, then it's a 2010 model year most likely....I'd hate to buy a current Prius and then a new one comes out 12 months from now...!
#141 of 311 Re: 2009 [xhe518]
Feb 21, 2008 (5:26 pm)
Toyota is notoriously zipped-lipped about new offerings unless it suits their purposes to generate new interest.
The Prius has a very very loyal owner/fan base that's chomping at the bit to get some tidbit of real data on the next generation. All that Toyota has said is that they decided to delay implementation of the Li-Ion batteries until more validations could be done. I believe that they stated these would be at least 2 more years down the road. 2011 MY?
But they also denied that there was any delay in the production of the next Gen. Implying that it would be coming out 'on schedule' - whatever that is. The normal schedule for Toyotas is 5 years. That would put the next Gen coming here in mid-Oct of this year. Speculation but I'd feel confident of it.
My own speculation is that the body is somewhat redone but it's still a 5 door hatch which is one of the best features of the vehicle. I'd guess that it will use the 1.6L 1ZR engine that's already in use in Japan with improved electrics and gearing for somewhat more power and better fuel economy. The new HH has both an EV and an ECON mode. I can see the next Gen Prius having both as well.
Fuel economy? + 10-20% using the new EPA numbers.
There may also be a small Prius sedan with either really high fuel economy or one that has the same fuel economy as the 5 door hatch but a much lower price. There could also be a third version as well, pickup, small minivan, small utility vehicle? All speculation.
Interesting sidenote: When the first Prius' went on sale here in 2000 they were sold to a specific clientele . These buyers had to register with Toyota to be get on the list for one of the first ones to arrive here. These first buyers were called the Pioneers. When this current Gen was being brought to market in June/July of 2003 these Pioneers were given the opportunity to be the first ones to buy the new Gen. If you know one of these Pioneers you might keep an ear open to see if they receive an early offering from Toyota. I sold one of the first of the first back in July of 2000. This buyer also bought one of the first of the first of this current Gen.
#142 of 311 To Buy Now Or Not To Buy?! Help!
Apr 14, 2008 (6:49 am)
Here's the deal...I have a 2006 Subaru Outback with 32,000 which gets around 21-23 on the curvy roads and hills and 26-30 on the highway. I drive about 16,000 a year. I live rurally. I own my car outright. I would rather have better fuel economy than the AWD.
I can now sell my car for only a couple thousand less then what what I paid for it (I bought it barely used from a friend and I live in an 'Outback' high demand area) and buy a barely used '07 Prius. The difference with sales tax will be around $3,000.
Should I just wait a year and buy the new model, or do it now before my car starts to de-value rapidly, as the seem to do? ALSO, does anybody have an idea what the new Prius will look like? Thanks!
#143 of 311 Re: To Buy Now Or Not To Buy?! Help! [akg]
Apr 14, 2008 (6:59 am)
My seat-of-the-pants advice is to keep what you have. Is the $3000 difference in price realistic, and even if so, you can buy a lot of gas for $3000?
I would also think "barely used" Priuses would be hard to find and not much cheaper than new.
There were some photos earlier of what the 2009 Prius might look like, but I think these were photoshopped expectations and not the real deal. Basically the same overall shape, but swoopier.
#144 of 311 Re: To Buy Now Or Not To Buy?! Help! [210delray]
Apr 14, 2008 (2:24 pm)
Thanks! I am sort of feeling the same way. I was hoping they would modify the style a little, but we'll see. When do you think they'll come out with the plug-in option? I know the technology is rapidly progressing, but still $$ out of reach and would compromise the warranty for an after market plug in.
I can't believe that an innovative company such as Subaru hasn't come up with a Hybrid.
#145 of 311 Re: To Buy Now Or Not To Buy?! Help! [akg]
Apr 16, 2008 (8:44 am)
"I can't believe that an innovative company such as Subaru hasn't come up with a Hybrid. "
Subaru developed a hybrid a few years ago but didn't bring it to market because they couldn't meet a resonable pricepoint (read: It cost too much to manufacture). Back in 2005, they were considering using existing Toyota technology and work out a technology trade (toyota hybrid driveline for Fuji Heavy Industries lithiumion battery tech.). However, as of 2006, it looked like they determined they couldn't use existing Toyota drivetrain. See below.
"Reuters is reporting that the two automakers have decided to jointly develop a new hybrid system instead. Apparently, Subaruís symmetrical all-wheel-drive has proven too complex to simply plug Toyota's Hybrid Synergy Drive system in.
[Source: Nihon Keizai Shimbun via Reuters]"
There hasn't been much talk recently, but it still seems a long way out according to this
Even the Subaru website doesn't serve up anything too optimisitc on a reasonable timetable.