Top 10 Tech Cars 2007

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  • 34 IEEESpectrum|April2007|NA www.spectrum.ieee.org

    Electric cars are backAboutAyEArAgo,theunitedStateswascomingoffagaso-linepriceshock,hybridelectricvehicleswerethestateoftheartinproduction-cartechnology,andso-calledplug-inhybridsweresomethingonlyafewgaragehackersandgreenextremistsdidforfun.theworldslargestcarcompany,generalMotorsCorp.,waslockedinaboardroomfightwhileitsNorthAmericanproductswith-eredonthevine.

    Ah,whatadifferenceayearmakes.today,thestateofthearthaspassedbeyondhybridstotechnolo-

    giesthatseemeddeadorridiculouslyexoticevenayearago:pureelectric-drivecars,includingfuel-cellvehicles;andplug-inhybrids,whichgivetheoptionofchargingthehybridsbatteriesdirectlyfromawallsocket.Dontlookforsuchcarsinshowroomsanytimesoon,butnoticethatsomeprettyspecificideasabouthowtheywillenterthemarketarestartingtoemerge.Andsomeofthoseideascomefromanunlikelysource:gMitself.

    butfirst,arealitycheck.Nearly50millioncarsandlighttrucksweresoldbymajormanufacturersworldwidelastyear.Noneofthosevehicleswerepureelectrics,andonly350000lessthan1percentwerehybridsofonesortoranother.by2025,saysPhilipgott,amarketforecasteratindustryanalystglobalInsight,12percentoflightvehiclessoldgloballywillbehybrids.Another12percent,hesays,willbediesels.

    Fewanalystswillevenhazardaguessaboutwhenthefirstpureelectricswillshowupintheshowroomsofmajormanufacturers.butgMisclearlystrivingtobethecompanythatputsthemthere.theautogiantannouncedseveralconceptsandtestfleetslastyear,allbasedonacommonsetofcomponentsusingelectricmotorstopowerthewheels.

    EvenasgMstruggledtoregainthehighgroundintech,ittookmorethanitsshareofpublicrelationshits.therewasthenewsthatitwillalmostcertainlyhavetocedetotoyotaitscrownastheworldslargestautomaker,eitherthisyearornext.ItsatitlegMhasheldfor70years.thecompanyshedmorethan30000employeesinNorthAmericalastyear(itpledgedtoreinvestsomeofthesavedcashintechnology).

    ManyobserversremainskepticalofgMsgoals,pointingtothethreedecadesthecompanyspentaggressivelybattlinganyandallregulationinthefieldsofsafety,emissions,andenergyusage,whilealitanyofgMinnovationslanguishedinlaboratories.therewasthecompanysromancewithhydrogen,forexample,exemplifiedbyHy-wire,gMs2002fuel-cellcar.CarspoweredbyhydrogenfuelcellsremainingMsvision,buttheyvebeenrecastasapieceofalargerstrategyinvolvingelectric-drivevehicles.

    Severalothermanufacturershaveunveiledfuel-cellconceptcars,includingHondawithitslatestFCX,whichmadeourlistthisyear.Andtheresmorethanonewaytospinwheelswithhydrogen:bMWandMazdaeachreleasedroughly100produc-tionvehicleswiththeabilitytoburnhydrogenintheirinternal-combustionengines.

    oneofthebiggestobstaclestohydrogen-poweredcarsisthelackofglobalhydrogenproductionanddistributioninfrastructure.buttheautoindustrywasjoltedbyincreasingspeculationlastyearthatasChinabuildsanetworkoffillingstations,itmightpossiblyusethemtodistributehydrogenaswellasgasolinejump-startingtheglobalfuel-cellvehicleindustryinawayimpossibleinmoredevel-opedmarkets.

    Suchastrategywouldassuagefears,asChinagoesmobile,ofavastgreenhousegasupsurge.theChinesemiddleclassisfindingoutwhatotherslearneddecadesago:carsarebulwarksofpersonalfreedomand,inthelargerpicture,ofeconomicgrowth.Fortunately,carstodayarecleaner,safer,morecapable,andmorereliablethanever.

    thattrendwillgoon,probablyforever.Meanwhile,ourcollectivevisionofwhatconstitutesacarisevolvingwiththetechnologythatmakesitgoandfeedsourfantasies. n

    Ithaslithium-ionbatteriesandcomeswithachargingcable,justlikeyourcellphone.unlikeyourphone,however,itcangofromzeroto100kilometersperhourinlessthan4seconds,pinningyouagainstthebackofyourseatlikeafighterpilot.AnditlldoitwithalotlessnoiseandforuS$70000lessthanaFerrariF430.

    CreatedbyteslaMotors,aSiliconValleystart-upinSanCarlos,theteslaroadsterispoweredby6831mass-marketlithium-ionbatteriesandcostsabout$100000.Wantone?Fine,justputdown$75000nowandwaituntilsummer2008totakedelivery.

    theteslawasengineeredbyEnglandsLotus,renownedforitssmall,lightsportscars.thecarweighsjust1100kilograms(2425pounds),nearlyathirdofthatbatteryweight.Withits185-kilowattmotor,ithasatopspeedof210km/h(130mph).

    Aswithanypureelectriccar,thekeyparametersarethebatteriesrechargetime,energydensity,andusefullife.thepointofreference

    2007 Roadster

    A new kind of car from a Silicon Valley start-up

    POWER PLANT n185-kWelectricmotor

    TRANSMISSION n2-speedelectricallyactuatedmanualnrear-wheeldrive

    CLAIMED RANGEn400km

    MOREAmongthecarsbuyersaretheusualeco-celebs.ActorsgeorgeClooneyandDennisHaysberthaveplunkeddowndeposits.

    By John VoElckER

  • www.spectrum.ieee.org April2007|IEEESpectrum|NA35

    A new kind of car from a Silicon Valley start-upistheonlyrecentelectricvehiclefromamajormanufacturer,thelate,lamentedgeneralMotorsEV1.WhentheEV1wasintroducedin1996,itranonlead-acidbatteries,hadamaximumrangeof95km(60miles),andtookupto12hourstorecharge.theteslausesthesamelithium-ionbatteriesfoundinlaptopsanddigitalcameras.theirenergydensitycanbeashighas160watt-hoursperkilogramoratleastfourtimesthatoftypicallead-acidcells.Sotheteslahasa400-kmrangeand,bestofall,itcanrechargeinaslittleas3.5hours.

    unresolvedatthemomentistheissueofbattery life.Laptopbatteriesusuallydontlast the 10 years required of major auto-

    motivecomponents.Andteslahasindicateditexpectsitsbatterypackspowertodegradeupto30percent inasfewasfiveyearsor200000km.Morethanadozencompaniesaretryingtodeveloplithium-ionbatteriesinsizesandpackagessuitableforautomotiveuse.Whenoneofthemsucceeds,thetacticoflashingtogethermanysmallcellsbolsteredbyinstrumentationtomonitorandaccommodatethepowerorthermalvariancesamongthemprobablywillend.

    teslaMotors ishardly theonlynewEVmakerthesedays,thoughits$40millioninventurefundingputsitatthetopofthelist.globally,morethantwodozencompaniesare

    offeringelectriccarsofalldifferentsorts,fromdrabecono-boxestosupercarsliketheteslaroadster.

    Meanwhile,asofJanuary,teslahadsoldmorethan250carsatidysumat$100000each.thefirstcarsaresupposedtobedeliv-eredinSeptember,ifcrash-testanalysesandotheru.S.government-certificationrequire-mentsgosmoothly.

    teslaalsohasplans for a secondcar, asportyfour-seatsedancode-namedWhiteStar.thecompanyhopestolaunchthatcarby2010,atapriceof$50000.todoso,ithassetupanengineeringcenterinrochesterHills,Mich.,andplanstostaffitwithmorethan50engineers.n

    By John VoElckER

    tESLAM

    otorS

  • 36 IEEESpectrum|April2007|NA www.spectrum.ieee.org

    POWER PLANTn100-kWhydrogenfuelcell

    CLAIMED FUEL EFFICIENCYn435kmfrom171litersofhydrogen,storedat350atmospheres

    MOREHondaletjournaliststakethecaroutonthebankedtesttrackatitsr&DcenterinJapan,atspeedsupto140km/h(87mph).

    top 10 tech cars

    POWER PLANT nVortecV8(displacementnotreleasedatpresstime)

    TRANSMISSION ntwo-modehybridsystemntwo40-kWelectricmotorsnthreeplanetarygearsetsnAll-wheeldrive

    CLAIMED FUEL EFFICIENCYn10.5L/100km(estimated)

    MORE two-modehybridsystemisplannedforpickuptrucks,too.

    gMCsyukon is a strapping2500kilogramsunloaded.Inotherwords,itaintnoPrius.

    And yet, yukons f it ted with gMs newtwo-modehybrid systemuseessentially thesameprincipletoreduceenergyconsumptionastoyotascelebrity-friendlyit-car.Anelectricdrivecanpowerthevehicle,byitselfortogetherwiththecombustionengine.thebatterythatpowersthemotorischargedbytheengineandalsothroughregenerativebraking.

    beingasbigasitis,though,theyukonout-doesotherhybridsbyhavingtwoelectricdrivemotors,eachcapableof40kilowattssustained.Asinglemotorwithenoughtorquetomovesuchamasscouldntbeaccommodated insidethetruck.SogMsengineers,who ledadesigneffort that later included engineers fromDaimlerChryslerandbMWaswell,usedapairofelectricmotorsasystemgMhadpreviouslyputintoproductionforitshybridtransitbuses.AsinthePrius,theyukonsmotorsareactuallymotor/generatorsthatcanproducetorquewhenfedwithelectricityorviceversa.

    thesizeofthesystemwasconstrainedbytheneedtofititintothesamespaceasthecompanys6-speedautomatictransmission.Insideanalumi-numcasingarepackednotonlyfourfixedgearsbut(fromfronttorear)aplanetarygearsetandelectricmotor,aclutch,asecondplanetarygearsetandmotor,andthenafinalclutchandgearset.Ineachplanetarygearset,acentralgear(thesun)isspunbytheengineorelectricmotor.thesunissurroundedbyplanetgearsthatarein

    turnsurroundedbyaringgear,whichdrivesorisdrivenbyanothermotor.byvaryingthespeedatwhichtheplanetgearsspin,youalsochangethepowersplitbetweenthetorqueonthesunandthatontheringgear.beingabletosplitthepowerarbitrarilylikethatletsyouchanneljusttherightamountoftheenginespowertothewheels;therestisdevotedtochargingthebatteries.

    thetwomodesofgMssystemreferstothedifferentmixesofelectric-motorandcombustion-enginetorque.thefirst,orinput-split,modeisforlow-speedandlight-loadapplicationsfromlaunchthroughsecondgear.Asinexistingsingle-modehybridsystems,aplanetarygearsetsplitsenginepowerbetweenthewheelsandoneofthe

    twoelectricmotors.Actingasagenerator,thismotorchargesthebattery,whichpowerstheothermotor,whichdrivesthewheelsaswell.Inthismode,theengine-controlsystemalternatesamongelectric-only,engine/electric,andengine-onlydrive,choosingtheoptionthatprovidesthebestperformancewiththelowestfuelconsump-tion.Fromrest,energyfromthe300-voltnickel-metal-hydridebatteriespowersthedrivemotor,whichisquicklysupplementedbytorquefromtheengine.

    thesecond,orcompound-split,modeisforhighspeedsandheavyloads.Itprovideselectricassistinthethirdandfourthgears.Here,bothelectricmotorscanreceivetorquefromtheengine

    2008 yukonTwo-Mode hybrid

    A hybrid heavy hauler

    FcX / concept

  • www.spectrum.ieee.org April2007|IEEESpectrum|NA37

    Ifyouwantone,youllhavetowaituntil2018atleast,Hondasays.butstill,itslatestFCXconceptcartakeshydrogenfuel-cellpower

    trains intoanew,sleeker realm. It saradical, stylishdeparture from the

    previousFCXsupright,slab-sidedhatchbackdesign.

    HondarevealeditsnewFCXthis past summer, around thesame time gM previewed itsChevroletSequelfuel-cellvehi-cle.but the twocarscouldntbemoredifferent.theSequelis a conventionally attractivesport-utilityvehicle,buttheFCXisalow,four-door,five-passengersedan.Itwouldlookrightathome

    ontheAutobahn,althoughitsmaxi-mumspeedof160kilometersperhour(100milesperhour)wouldntwinitmanyfriendsintheleftlane.Itispoweredbythecompanysthird-

    generation fuelcell,which is20percentsmallerand30percentlighter,andat100kilo-watts,14kilowattsmorepowerful.thenewV(forvertical)Flowstackstandsupright,andcanbepackagedinwhatusedtobecalledatransmissiontunnelbetweentheseats,low-eringthecenterofgravityanddoingawaywiththecharacteristictall,uprightdesignofmostpreviousfuel-cellvehicles.

    Moreimportant,thedesignhelpseliminateoneofthebiggestobstaclestomainstreamuseoffuel-cellcars:thecostandcomplexityofthesystemsneededtoletthecellswithstandsub-freezingtemperatureswhentheyrenotrunning.Waterisaby-productofthereactionthatliber-ateselectricalenergyinafuelcell.butanywaterremaininginthecellsstack,wherethereactionoccurs,wouldcausedamageifitfrozethere.InHondasvertical-flowdesign,gravityhelpsdrainthatwaterimprovingperformanceandreducingthepowerneededtopumpthestackdryeverytimethecaristurnedoff.AccordingtoHonda,thesystemworkssowellthatthecarcanstartattemperaturesaslowas20C.

    Witha smaller and lighter95-kWdrivemotor,thenewFCXscompletepowersystemis180kilogramslighterandalmost40percentsmaller than its predecessors. Hydrogenisstored ina 171-liter tankatapressureof350atmospheres,givingthecararangeof435km(270miles),Hondasays.

    HondaplanstoputthecarintoverylimitedproductioninJapannextyear.Still,itsastepforward:virtuallyallfuel-cellcarsbuiltsofarhavegoneintocarefullymaintainedandshel-teredfleetsatutilitycompanies,forexample.butHondasaysitisconsideringleasingthecarsforuS$600or$700amonthtointerestedpri-vatecitizens,togetreal-worldfeedbackonhowthenewFCXdrives,rides,andperforms. n

    can a fuel-cell car be sexy?

    Standonastreetcornerinanymiddle-classsuburbinbrazilandwelloverhalfthecarswhizzingbywillbeflex-fuelvehiclescapa-bleofburningvariousmixturesofgasolineandethanol.

    Amongbrazilsmanyflex-fuelcars,aver-sionoftheFiatSienastandsoutbecauseitrunsonanyblendofethanolandgasoline,andalsoonpurenaturalgasaswell.Itburnsthenaturalgasfirstbecauseitsbrazilscheap-estcarfuel.

    theSiena stores the liquid fuel in a48-liter tankand thenaturalgas in two6.5-cubic-metercylindersinthetrunk.the1.4-Lenginehastwosetsofinjectors,oneforliquidfuelandasecondfornaturalgas.butthosearetheenginesonlymajorhardwaremodifications.theengine-controlunit(ECu)isthesameastheoneonordinarySienas.Itjustrunsmoresophisticatedsoftware.

    thecarsexistingsensorsmeasuretheairflow intocylinders, theengine speedandload,andthespecificfuelbeingsenttotheengine.thedataarefedtotheECu,whichusesthemtooptimizefuelinjectionandsparktiming.Mostimportant,theECuusesdata fromthesensor thatmonitorsoxygenintheexhausttovarytheair-fuelmixcontinuouslyuntilthatsensordetectsnooxygenremainingintheexhaust,indicat-ingcompletecombustion. n

    2007 Siena Tetrafuel

    POWER PLANT n1.4-L4-cylindern59kW(gasoline,ethanol)n50kW(naturalgas)

    TRANSMISSIONn5-speedmanual

    CLAIMED FUEL EFFICIENCY n5.6to7.7L/100km(gasoline)n8.3to11.5L/100km(ethanol)n15to20km/m3(naturalgas)

    MOREAt6270litersperhectare(670gallonsperacre),brazilsproductionofethanolfromsugarcaneisnearlytwiceasefficientasu.S.productionfromcorn,accordingtotheEarthPolicyInstitute.

    Research and translation for this segment was provided by Erico Guizzo.

    Auto omnivoreandpowerfromthebattery.thesecondandthirdplanetarygearsetsnotonlysplittheenginepoweramongthedrivewheelsandtheelectricmotors,theycanmultiplyalltorquetodelivermaximumpowertothewheels.

    Controllingitallaremicroprocessors.Infact,accordingtochiefengineertimCrewe,70percentof the total effort involved indesigningandtestingthesystemwenttowardcontrollogic.thatlogicanalyzeshundredsofinputsevery10milliseconds,includingvehicleload,engineoperations,batteryparameters,andthetemperaturesinthehigh-voltageelec-triccomponents.Dependingonvehiclespeedandpowerrequirements,onemotor-generatormayassisttheengine,orprovideregenerativebraking,withtheothershutdownforgreaterefficiency.orbothmotorscanprovideboostorbrakingsimultaneously.Andthecombina-tionofplanetarygearsetsandelectricmotorssmoothstheshiftingamongmodes,sothatenginespeedcanstayconstantevenasitvar-iestheelectricpowerdeliveredtothebatteryordrivewheels.

    Whencoupledwithcylinderdeactivation,thetwo-modehybridsystemisexpectedtoimproveoverallfueleconomyby25percent,to10or11 litersper100kilometers(about22milespergallon).Forcomparison, thestandardgMCyukongets15to16L/100km(roughly15mpg)inthecityand11to12L/100km(20mpg)onthehighway,accordingtotheu.S.EnvironmentalProtectionAgency. n

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  • 38 IEEESpectrum|April2007|NA www.spectrum.ieee.org

    POWER PLANT n120-kWelectricmotornturbocharged1-L3-cylinderenginen53-kWgenerator:recharges16-kWhbatterypack

    TRANSMISSION nNone;electricmotordrivesfrontwheels

    MOREoneoftwocarsthisyearnamedforanelectricitypioneer,theotherbeingthetesla.

    Volt / concept

    POWER PLANT n125-kW1.4-Lturbochargedandsupercharged4-cylinder

    TRANSMISSIONn6-speedmanualnFront-wheeldrive

    CLAIMED FUEL EFFICIENCY n7.2L/100km

    MOREAfterhistestrun,notoriouslyirritablereviewerJeremyClarksoncalleditoneofthef iveworstcarshehaseverdriven.

    Powerful small-displacementengineshavealwaysbeenaEuropeanspecialty.buteveninEurope,anengi...