2001 - 2003 Toyota Prius

Discussion in 'New Automobile Specifications' started by xcel, Jun 7, 2007.

  1. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    2001 - 2003 Toyota Prius



    Engine Type: In-Line 4-Cylinder
    Engine Block/Cylinder Head: Aluminum-Alloy
    Displacement (cc): 1497
    Horsepower @ rpm: 70 HP @ 4500 RPM
    Torque (lb.-ft. @ rpm): 82 lb.-ft. @ 4200 RPM
    Bore and Stroke (mm): 75 x 84.7
    Compression Ratio: 9.5:1
    Expansion Ratio: 13.0:1
    Valvetrain: DOHC 16-valve VVT-i
    Multi-Point Fuel Injection
    Drive-by-Wire Throttle System
    Front-Wheel Drive
    CARB Emissions Rating: SULEV
    Federal Emissions: Tier II/Bin3
    Direct Ignition System with Immobilizer

    THS Electric Motor/Generator:

    Power output: 44 hp @ 1040-5600 rpm (33 kW)
    Torque: 258 lb.-ft. @ 0-400 rpm (350 Nm @ 0-400 rpm)

    THS Power Storage

    Voltage: 273.6V




    Unit-Body Construction
    MacPherson Strut Front Suspension
    Torsion Beam Rear Suspension
    Electric Power-Assisted Rack-and-Pinion Steering
    Steering Wheel Turns, Lock-to-Lock: 3.99
    Steering Ratio: 16.4 – 18.3:1
    Turning Diameter, Curb-to-Curb (ft.): 33.5 ft.
    Power-Assisted Ventilated Front Disc/Rear Drum Brakes (in.): 10.04/7.87
    Wheels: All-Season Tires: P175/65R14
    Compact Spare Tire


    Interior Measurements:

    Headroom (in., front/rear): 38.8/37.1
    Legroom (in., front/rear): 41.2/35.4
    Shoulder Room (in., front/rear): 52.8/52.2
    Hiproom (in., front/rear): 50.7/51.9
    Cargo Volume (cu. ft.): 11.8
    Passenger Volume (cu. ft.): 88.6
    Seating Capacity: 5

    Exterior Measurements:

    Wheelbase (in.): 100.4
    Length (in.): 169.6
    Height (in.): 57.6
    Width (in.): 66.7
    Track (in., front/rear): 58.1/58.3
    Curb Weight (lbs. MT/AT): 2765
    Weight Distribution (%, front/rear): 62/38
    Cd: 0.29

    EPA Mileage Estimates/Capacities:

    07 EPA (City/Highway): 52/45 mpg
    08 EPA (City/Highway): Guesstimate of 42/41 mpg
    Crankcase (qt.): 3.9
    Coolant System (qt.): 7.9 total for ICE and Inverter/converter
    Fuel (gal.): 11.9
    Required Fuel: Regular Unleaded

    Last edited: Jun 8, 2007
  2. Tochatihu

    Tochatihu Well-Known Member

    Also known as NHW 11. The only correction that jumps out at me is 175 mm width stock tires, not 165. Maybe different outside the US?

    Side air bags were not an available option in 2001 when I bought it, but are desireable in 02 and 03 models (if one is looking for a nice used car).

    One might anticipate total operating costs of high-20s cents per mile with shop maintenance, or low-20s with (easy) DIY. The most common squawks are ECM and power steering replacement, both of which should have been done (by now) under warranty for affected vehicles. Some bad accelerator pedals before VIN ...45000 Bob Wilson has taken over my "Maytag repairman" pedal rebuilding service. HV battery resealing and crankshaft position sensor replacements should also have been done by now on the affected vehicles.

    Align the suspension for as little toe-in as you can stand. Zero toe-in rolls very easy, but requires a steady hand on the tiller and won't please all drivers (mine is 0.05 in on each side and I could probably manage with less).

    Toyota does not mandate transmission fluid change intervals, but experience has shown that 60k miles is a sensible precaution. Maybe even a bit more frequently? On the first change, also buy the pan gasket, so the pan can be inspected for metal chips and cleaned if needed.

    If you like quiet like the NHW 20, Put sound-absorbers in the front doors and under the hood. They really work. Adds 40-ish pounds. If you hate donut spares (like I do) a really spare tire can be squeezed into the well, unlike the NHW 20 :) Adds 10 pounds more, about.

    As far as we can tell from the internet groups, HV battery or transmission failures are each less than 1/1000, so far. I have developed high confidence in both systems, presuming fluid change as above. Driving in big mountains can get the HV battery up to 50 oC, which is a bit above the NiMH comfort zone. Without extra instrumentation, one wouldn't know this, so I recommend using the air conditioner on flow-through mode when 'doing mountains'. On one ocassion I even had to put on a sweater inside, but HV battery health is a high priority for me. Driving on the flats, it does not seem to get hot, even in the summer.

    Toyota spec'ed the NHW 11 for 7500 mile engine oil changes; 5W30 conventional oil. Based on used engine oil analyses (UOA), Mobil 1 (and probably other synthetics), do very well for 12k miles, when the total base number gets a bit low. This engine delivers fabulously low wear metal numbers in the UOA, so any problem is going to stick out like a bad thumb. That is, if you do UOAs :)

    With almost 100 amps available from the DC/DC converter, it is an excellent candidate for a 1000 (or so) watt 110 volt AC inverter. Adds 10-15 pounds. Keep your basement sump pump alive during power outages, or just to make expresso while car-camping, like I do. Operated in this way it has the same specific fuel consumption as those little Honda (TM) gas generators; a bit quieter, and much less polluting.

    I have encountered a couple of interesting NHW 11 failure modes. If you are climbing a steep enough highway under cruise control, and the HV battery gets low, cruise will drop out and you are gonna feel like dead. Just step on the right pedal and enjoy that famous 'ICE roar'. It'll go just fine. The other requires you to climb *really* steeply at really low speed. This I did on a wholly inadviseable 'road' in Death Valley. Eventually, something gets too hot and the go pedal has no effect. A hood-up cooling session cures it. This happened before I got 'instrumented' so I don't know the cause, but I now suspect MG1 temperature. That was about 70 k miles ago for me, and surely things are fine. Nothing like seeing the errors screen light up for your first time though :)

    Clean the throttle butterfly every 60 k or so. Replace the PCV valve eventually. Inspect the CV boots for gease and cracks when you rotate the tires. With the rear end up, make sure that the brakes don't drag.

    Why it's better than the NHW 20: Less cost for a used one. Lockable trunk. "B mode' works along with the cruise control. You can manage brake fluid and the 'electricals' coolant loop without Toyota's THHT! A bit more rear seat head room. Climate controls do not confuse cavemen.

    Why it's worse than the NHW 20: 5-10% less fuel economy in the hands of 'typicals'. No pushbutton start, bluetooth, and all that 21st century stuff. Cargo volume and space-versatility. Noise levels, unless adding sound deadening as above. You have to be 'xcel-like' to knock out 78 mpg in the flats :)

    With appropriate maintenance, I see no reason to doubt that the NHW 11 would perform suberbly for 300k miles. or more, or until suitable fuel is 'not commonly available'. Best car I've ever had.

  3. philmcneal

    philmcneal Has it been 10 years? Wow

    The two months I've own a NHW11 prius, I can definiately say with proper anticipation of traffic lights and proper changing of fluids (I switched to 0-20 M1 and type WS fluid for the car when it should be using 5-30 and type ATF fluid) as well as pumping 60 psi into those RE92... (58 mpg was my best tank) I can definately say I still miss that NHW11 sometimes however...

    believe it or not, I managed to trade my NHW11 to a NHW20 for free! despite the sacrafaces I made for it (more miles, had a small bumper accident, and taxi color!)

    although I didn't do any DIY on the NHW20 as I did on the NHW11 (my first oil and transmission change was on that prius! pretty rewarding for a mechanial noob's first time!) I must say Toyota's prices are pretty on par these days.... I'm just too lazy to DIY like I did last time (I spent 5 hours trying to figure out if I drained the tranmission oil or the engine oil :S)

    But yeah only thing I miss on the NHW11 is the small turning radius, other than that I love my NHW20 to death... NHW20 has more smart functions that just make it a 5-10% better economical car while offering much more cargo space! As well if I'm not mistaken, the electric motor has more punch so better off the line starts! I smoked a V6 Dekota the other day IN THE RAIN and I gave him two rematches.
  4. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Doug:

    ___Great overview! Must be a typo and it now back to 175 ;)

    ___After reviewing maybe 20 spec sheets on the Prius I around the web, I finally had to call Toyota media who then put me into contact with a product guy by the name of Bill Kwong. What a lifesaver as he gave me the weight distribution, brake sizes, and steering wheel turns to lock to finish out the Prius I specs.

    ___And I am still in total wonderment as to this little beauties capabilities … I think many simply missed out on what the NHW11 can actually receive over a round trip commute as my own 80% highway/20% city commute shows below.


    ___Good Luck

    Last edited: Jun 9, 2007
  5. Tochatihu

    Tochatihu Well-Known Member

    Hey thanks Wayne, for pickin' at my scabs!

    "many simply missed out on what the NHW11 can actually receive"

    Depends on who she's dancing with, my friend. Yrs trly needs some topography for a screen like that. Or a totally uncharacteristic degree of concentration and empty rear view mirror (whine)

    "the [NHW20] electric motor has more punch"

    Sure does. 500 volts to the windings, spooky focused magnets, and relaxed rpm limits means that the MGs are pretty darn good at turning electrons into move-ons.

    The NHW20 NiMH also has an electrode design that I would call "biological', and that is pretty high praise! For these reasons (plus a few others), when I am chugging along at 60 and a '20 zips by, I have to *know* that their FE is mine or better.

    It is a pain you have never felt, master Wayne.

  6. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Doug:

    ___I almost wish you were writing the upcoming review because this Prius-I just keeps getting better and better! I think I will send a final draft your way for a quick scrub but it will be the std. fare with the FE numbers acting as icing on the cake.

    ___I have never really pushed a Prius II out on the highway so I have no idea but having to continually manipulate the NHW11 to make it do what a Prius II can do below 41 mph naturally is a bit disconcerting to say the least. I am learning my own tricks with each mile but the learning curve is extremely steep given the vehicle will be leaving me at the end of its first full tank later in the week :ccry:

    ___Either way, I am really growing to like this Prius-I as each and every mile accumulates. If the Prius community would have known back in 01/02 what we know today, I bet there would be a lot more NHW11’s on the road. It is a rabid wolf in sheep’s clothing given what I am seeing these past few days …

    http://www.cleanmpg.com/photos/data/523/Prius_I_MFD_79_3_at_189_miles_-_Commute_RT.jpg : New tank after SG-II calibration shown previously. She offers something most probably never knew was possible :(

    ___Good Luck

    Last edited: Jun 9, 2007
  7. FireEngineer

    FireEngineer Well-Known Member

    Sure wish you could get a block heater into that Prius I, your start-up would be a world better.

  8. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Wayne:

    ___I wish I had an EBH and an EV button in her (I know the EV button is not in the cards for the NHW11 :() because it would definitely help but I believe there is a way to lessen the hit by FAS’ing her. It worked for me this morning but you do have to come to a complete stop, shift her into P, shut down, reboot and when the ICE ignites, back into D for an easy pulse and repeat … A kludge at best but she was at 66 mpg just 2 miles out from dead cold this morning which was a lot better then that mid 30 - low 40 stuff I was seeing just a few days ago in similar temps. She moved up quickly afterwards too! All the while not really knowing what the heck I am doing but am learning as fast as I can :rolleyes:


    ___I also had the opportunity to experience my first 3 mile - Chicago style - Stop and Crawl at the O’Hare I-90/I294 junction this morning. This is the first time I have had the right tools to take on those SOB’s and conquer them with a gain in FE vs. the losses I have experienced in every other hybrid and non-Hybrid I have ever driven. It was quite exhilarating to see (2) 90 + 5-minute bars and a pegged 5-minute bar afterwards while traversing through it :D

    ___She may not be an NHW20 either in the back country or out on the highway but darn if she isn’t giving her all to show the Prius II owners that she has some tricks of her own they may not have seen or experienced yet ;) The Prius-I is one tough little animal if I do say so myself!

    ___If Honda does not get there act together and work on a strong hybrid of their own soon, they will be assimilated just as the domestics are but do not know it yet …

    ___Good Luck

  9. Tochatihu

    Tochatihu Well-Known Member

    Dang, Wayne, you're good! It is a big think to come up with something worthwhile to say.

    We may keep some cardboard in front of the main radiator, until the A/C is called for, or until 95 oC engine coolant triggers its fan. Both of those trigger the fan, and indicate 'pull cardboard out'. Until then the NHW11 ICE is completely capable of managing its own heat, thank you very much. Leave cardboard in.

    Recognizing that some NHW11 drivers will be wearing ice vests :), I will mention another time to use the A/C. Just as I suggested earlier, big mountains heat the HV battery, with little regard to outside air temp. Ripples as small as 200 meters on the topo might do so as well, but my HVB health determinations are based upon the Graham Davies miniscanner. Scangauge and similar will greatly aid the hypermiler, but AFAIK no other OBDII plug-in can help with 'systems health' here. Too bad Graham's minis are so rare!

    Here I am outing myself as more concerned for overall system survival, opposed to lowest fuel use. Well then, fine. We have got to keep the NiMH below 50 oC; typically below 45. The vent fan will do its best, but the 'hyperlongevity' driver will help with the A/C at need. The hypermiler may also appreciate that battery I/O is going to be severely curtailed during hot times.

    The only other interesting temperature I've found is MG1. With hot day and heavy load it can exceed 105 oC. Have been consoled (elsewhere) that 140 is OK, but I'm not buyin' it. By 120 if not before, Tocha will get a hood-up cool-down, on the side of the road.

    So there you have it. Do (almost) anything you like on the flats, but please have a care for heat when you are on big hills.

    Wait, one more, the HV module voltages when cold. Toyota (apparently) declares the HVB replaceable if the max/min module voltages differ by 2. Routinely, my diff (after 106 k miles/6.8 yrs) is 0.15. But when I start the car after a good cold soak to 10 oC or below, a big power demand on the accel pedal will make that diff 0.3 volts. The hyperlongevity driver might wish to use the air heater liberally in cold start-ups, and limit power requests for quite a time after (that big battery box has a *lot* of thermal inertia).

    See my strategy forming up here. We who are not up to hypermiler dancing may conceal our shortcomings behind 'systems longevity'. Yeah, that's the ticket.

  10. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Doug:

    ___Thanks for the input as usual.

    ___A little input on what I am finding … Just like the Insight, an absolute minimal touch of the pack for assist (none) and minimal regen is best. On pulses, I know Hobbit and company love 1,700 - 2,300 which fills the pack nicely but on the NHW11, a much more leisurely 1,280 – 1,450 keeps you out of that heretical mode or whatever it was called (ICE to the MGSet and back to the wheels during Pulses from the mimic if that is what is really going on?) as well as a low C-Rate pack fill. Just enough to keep it at full from my views of the mimic? Anytime I extend Glides, it is completed usually below 8 mph and a very very light touch so as to creep around a corner or up a 5’ elevation type thing. I just know the average driver is running super high C-Rates on every EV opportunity or accel. The item I cannot get rid of is while going down the highway and all of a sudden the MFD iFCD is pegged for maybe ½ a mile. I see the Energy mimic shoving all kinds of assist in when none is called for :confused: I have no idea why it does that from a very light 47 – 53 mph steady load cruise (pack is going over SoC limits and lowering cap???) but I see why PHEV’s can certainly help at highway speeds although MG2 might not like a lifelong blast of current for what seems like forever? Also, on warp stealth’s, I have been attempting to run no-arrows vs. MG1 sucking off the pack. Again, does the mimic match reality? Still nice to see that pack barely touched on the coast down …

    ___In that stop and crawl this morning, I would build buffers like normal and go into a quick pulse to keep the pack full and glide down in N within traffic bounds. Talk about kick @$$ ;) Most of my glides are in N below 41 now as the Prius-I is fickle wrt holding a pure glide. Not quite like the Camry but the designed dead band appears not to be as wide as the NHW20? Just a few differences between the two but her mimic may be telling me one thing yet doing another?

    ___About temps … I am not really seeing an FE hit up to 55 mph with the front drivers window open 2” or so and the rear left window opened the same so that is where I keep them. Interior temps have been no higher then 85 (max ambient) or I would be sweating like crazy and that has not been hit yet. During the day, I have two windows full open in the drive just like the Insight. At work, both windows are cracked 1”. I wish more would use this method at keeping their interiors (and packs) not much beyond ambient during the summer months or during high sun loading period even in mid-winter.

    ___Good Luck

  11. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Doug:

    ___I think I forgot something else … To guarantee an ICE-Off condition after a pulse in a P&G scenario, a minimum of 35 mph should be breached. I got caught in that same scenario again tonight about a mile from work. I hate that ;) You can FAS or let her top off the pack. I thought I would let her top off the pack tonight to see how she acts in the morning during warmup.

    ___I do not know if you have seen the same but it makes for an interesting set of rules that must be followed for maximum FE in the NHW11 ;)

    ___Good Luck

  12. hobbit

    hobbit He who posts articles

    So xcel, when are you gonna finally knuckle under and trade the
    'cord in on a nicely broken in '04 or '05 NHW20?? You *know*
    you want it.
  13. Tochatihu

    Tochatihu Well-Known Member

    Another difference between the two Prius models seems to be that the NHW11 does not like to stray as much from 60% SOC, as does the new model. Both have soft limits at 40 and 80%, but the leash is tighter on the classic.

    I suppose that the new improved electrode design permits that, and that the battery management software has been loosened up. This may relate to the some of the model differences Wayne is seeing.

    As far as driving with partly open windows, no testing here, but my instincts say that if you can't hear them, they are not a big part of the energy story.

  14. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Hobbit:

    ___I have to pass this one on. You Prius and FEH guys have no idea what kind of animal you are driving. I got caught in a 5 mile stop and crawl just south of O’Hare all the way to the Touhy Avenue Toll plaza this morning. I buckled down for the std. Battle Royale and darn if that thing started pushing numbers that would make an Insight cry. A touch of EV to keep her going while DWB and when it would open up, a quick Pulse to help maintain her SoC. Those 5 miles took all of 30 minutes and (1) 5-minute bar was pegged, (1) was at 95 (or whatever one small gap from the top), (2) were at 90 and (1) was at 85 mpg. I drive this kind of garbage almost daily after mornings and in the afternoons when on day shift and to think the Prius-I is worth 90 + in this kind trash absolute floored me. I have seen the Insight loose a 100 mpg segment in that stuff as well as watch the Accord lose 7 - 10 mpg after 60 + miles. And here the NHW11 was picking up from her 78.5 at the entrance all the way up to 78.9 on the MFD at the exit after some 740 miles had already been accumulated! Good god you guys simply have to teach Prius owners they ways of the Hypermiler given what they drive on a daily basis.

    ___Depending on what Honda does with their upcoming iCDTi, I would have no problems seeing an 09 or 10 Prius III sitting in my drive ;)

    ___Doug, I sure do wish the NHW11 had more resolution on that SoC mimic. Half and Full doesn’t cut it other then to tell me when I do see half appear (I try not to see that :() , a higher speed pulse is in order and right darn now! As far as the drivers and rear passenger’s windows being cracked for highway ventilation, there is a heck of a raucous but taking down the SoC from a ventilation fan appears to be even more harmful and with less cooling then having the windows cracked in my short time behind her windscreen. I am just starting to jel with the ole girl and she will be out of fuel by morning. Then back into Cheryl’s hands by the weekend just a short 2 - 3 days away :(


    ___Good Luck

  15. FireEngineer

    FireEngineer Well-Known Member

    Expressway gridlock, fantastic MPG can be had. I-90/94 Dan Ryan during the construction, if I'm not in a hurry, can boost the tank at rush hour.

  16. hobbit

    hobbit He who posts articles

    I've been in the occasional crawls that just the running bunch
    of electronics is responsible for more fuel usage than propulsion.
    I've come to almost *welcome* traffic jams, and they're one of
    the few places where I can leave a huge gap and the idiots behind
    me actually might *understand* why I'm not closing it but rather
    doing a cute little time-averaging game that clearly gets me
    there [where?] just as fast as their expectation that I'd just
    ram up behind everyone else and cram on the brakes. The couple
    that go round and jump the gap don't affect me in the slightest,
    and per the "amasci" articles it's quite evident that overall
    traffic progress is being improved as I let more people do their
    maneuvering while I rack up similarly tall "castle walls" on the MFD.
    But then the jam clears, and I'm back to the normal sixtyish
    straight-n-level flying. So the normal day-to-day, with minor
    exceptions, winds up keeping the "monster" on a tighter leash..
  17. FireEngineer

    FireEngineer Well-Known Member


    If you would have changed the transaxle fluid to Type WS as in the current Prius you would have made 1,000. The Type WS is worth a 10-15% MPG improvement.

  18. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Wayne:

    ___I should have done it as I really wanted that 1K tank after seeing two pips while 850 miles out :(

    ___I found a few more secrets in her for the LS highway stuff I drive both last night and today. I wish I had another two weeks for the ATF and a few more days to keep wringing from her what she is still hiding? This is really giving me a heads up when its time to do a Prius II review though. We will see what happens tonight?


    ___And the next question of the day? I have seen this strange activity with the Energy Mimics first blasting out assist for 100 + mpg and then she is dragged down from something like a Forced Regen (you cannot see it on the mimic but you can see the iFCD drop to the low – mid-50’s). Each Assist cycle lasts about 15 – 20 seconds and then swaps to the “Regen?” cycle for maybe 45 seconds (total guess here?)? This usually happens after I enter the highway after a long stretch of P&G’s. Today it lasted almost 8 miles and I really cannot afford 8 miles of this 50 mpg stuff :angry: After this back and forth action subsides, she jumps right back up into the low 70’s, low 80’s while DWL. Previous days it only lasted about 3 - 4 miles but today was a lot longer. Traffic build was ridiculous so I was moving into and out of Warp Stealth and N-Glides through this period. Maybe her logic did not have time to finish up this recal like event and resets the clock each time you move into a new mode? It just had me confused is all given I am always riding with a full or near full SoC as of late and hate to see this action when it appears.

    ___Good Luck

  19. hobbit

    hobbit He who posts articles

    By the "mimic" I assume you're talking about that virtually
    useless energy-flow screen? The big problem with that is that
    it does not tell you *quantities* of anything, which is why the
    battery-current meter was one of the first things I added. It
    is very similar to the charge/assist display on Hondas, and
    heck, even Ford added one to the Escape. Any electric traction
    rig needs that, and I can't imagine why Toyota dropped that ball
    other than going for some misguided "ease of use" for the masses.
    Bottom line is you can more or less safely ignore all those
    animated arrows and just concentrate on engine management.
    The Prius very seldom has anything like a "recal" event, it
    just seeks 60% SOC all the time unless you're asking it to
    do something different. And engine-run is all based on a
    fairly simple demand vs. SOC relationship.
    See, you and I need to go out for a tool with you at the helm
    of *my* ship, and you'll start to see much more of what's going
    on in there...
  20. xcel

    xcel PZEV, there's nothing like it :) Staff Member

    Hi Hobbit:

    ___I have got to get you to put down the toys and start driving that beast the way it was meant to be driven which means by the iFCD of course! The mimics are estimates at best but the iFCD sure isn’t. Her capabilities really blew me away ;)

    ___Remember when we were trying to pull steady state 40 mph FE numbers from your Prius II last year before HF2006 and it started doing all kinds of whacky things down low. We even saw some of that at 50 IIRC. The Prius-I is doing the same thing but it is a little slower to respond. I always try and reverse compensate to hold within a few % of a new found setpoint (setpoint being an iFCD target) but with the Prius-I, everything I tried did not appear to work. Until the final 2 segments that is. Hopefully if you are caught in or are driving in or around the 45 – 50 mph range and see this kind of action in your Prius II, it may help manage your own let alone the little “Wolf in sheep’s clothing” I was driving ;)

    ___Good Luck


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