Dr Automotive Design and Tools

The third-generation Toyota Prius 50 MPG hybrid features a more aerodynamic shape, larger 1.8 litre petrol engine with optional roof-mounted solar panels and intelligent park assist. Unfortunately the 2010 Prius is not yet a plug in hybrid and still comes with a relatively small Nickel-metal hydride battery so EV only mode will not exceed approx 5 miles. While the current model Prius is EPA rated at 46 mpg, the third-generation Prius has increased fuel economy to an estimated 50 miles per gallon for the new Prius. (It has not been EPA rated as yet)

90% new Drive System

The move from 1.5 Litre to a larger and more powerful 1.8 litre Atkinson-cycle, four-cylinder engine should significantly improve the power to weight ratio and the performance of the Prius. The current 1.5Lt Prius has always scored well in city driving due to it’s regenerative braking but it has been noticeably lacking in highway performance due to it’s small engine capacity and the additional weight of a battery pack compared to vehicles with similar engine capacity. Contrary to conventional wisdom, the larger engine actually helps improve highway mileage. By making more torque, the new engine can run at lower average rpm on the highway. When operating at lower rpm, the new engine uses less fuel..

Toyota has used an electric water pump for the first time that increases engine’s efficiency by removing auxiliary loads from the engine’s crankshaft. These loads, such as the power steering and the air conditioning compressor, are powered directly from the 500v battery at achieve much higher energy efficiency. The 1.8-liter Prius engine is the first Toyota engine with no belts under the hood. The 4 cyl VVT-I puts out 98 hp (72 Kw) @ 5,200 rpm with 105 lb/ft (142 Nm) @ 4,000 rpm compared to 76hp (57 Kw) and 82 ft/lb (111 Nm) in the current model.

The Hybrid Synergy Drive system in the 2010 Prius is 90 percent newly developed with significant improvements over previous models. These include a lighter continuously variable transmission (CVT), an improved inverter cooling system and improved control logic to enhance brake regeneration.

The electric motor is still a permanent magnet AC synchronous motor (BLDC). Power has been increased from 50kw (67hp) to 59kw (80hp) while the Electric only torque figure provided in this press release says 153 ft/lb but the current model Prius has 295ft/lb (400Nm) so we’ll take that as a Toyota typo. Toyota say net hybrid systems power has increased from 110 hp (82 Kw) to 134 hp (98.5 Kw)

Worlds lowest Cd

The aerodynamic design of the new 2010 Prius was an important factor. The goal was to create a wedge shape with steeply raked windscreen and square rear end corners to reduce aerodynamic drag. The overall height of the Prius is the same, but moving the top of the roof 3.9 inches to the rear alters the roof profile. This also allows for enhanced rear headroom and improved aerodynamics. The new Prius received more hours of wind tunnel testing than any other Toyota in history, resulting in the cleanest aerodynamic profile of any mass-produced vehicle in the world. By focusing on the shape of the body, underfloor, wheelhouse liner and shape of the wheels, the designers of the new Prius were able to reduce the coefficient of drag (Cd) value to 0.25, compared to 0.26 for the previous model. The airflow under the car was studied extensively. Engineers made changes to the shape of the fender liner, front surface of the underfloor, and added a fin at the rear floor cover to increase linear stability.


An optional sliding glass roof is packaged with solar panels, located over the rear seating area, that powers a new ventilation system. This solar powered ventilation system uses an electrically powered air circulation fan that does not require engine assist. The system prevents the interior air temperature from rising while the vehicle is parked, making the cool-down time shorter when the driver returns to the vehicle, thus reducing the use of air conditioning. As it is usually hottest inside a vehicle when the sun is shinning rightest this should prove an efficient way to power a cooling system.

The remote air-conditioning system is the first system in the world to function on battery-power alone and that can be remotely operated, so the driver can adjust the interior temperature for comfort before getting in the car.
Reducing the vehicle's power consumption, potional LED (light emitting diode) lamps are used for low beams and also in the tail and stop lamps. Air conditioning, a major energy drain, has been re-engineered to increase efficiency and cool-down performance. In addition, an exhaust heat recirculation system reduces heat waste by warming engine coolant during cold startup, for improved performance. It also heats up the passenger cabin more efficiently.

Lighter chassis

The hood, rear hatch, front suspension axle and brake caliper are made from aluminium and the use of super high-tensile steel in the rocker inner, centre pillar, and roof reinforcement form a roll cage like safety cell for the occupants in the event of an accident. The 0-to-60 acceleration has been improved to 9.8 seconds, more than a second faster and disc brakes are now used on all four corners, replacing the front disc/rear drum brakes in the current model. Anti-lock Brake System (ABS), Electronic Brake Distribution (EBD), Brake Assist (BA), electronic traction control (TRAC) and Vehicle Stability Control (VSC) are included with Toyota's standard Star Safety System.

Dynamic Radar Cruise Control system, using advanced millimetre wave radar, is an available option. The system also enables Lane Keep Assist, which helps the driver stay safely within the lane, and the Pre-Collision System, which retracts seatbelts and applies the brakes in certain conditions when a crash is unavoidable.

Next-generation Intelligent Parking Assist features simplified settings to help guide the car into parking spaces. A back-up monitor, which provides a view of rear obstacles when reverse is engaged, is available with an optional voice-activated navigation system.

2010 PRUIS PRELIMINARY SPECIFICATIONS

POWERTRAIN
1.8-liter four-cylinder engine with VVT-i
Engine horsepower: 98 hp @ 5,200 rpm
Engine torque: 105 lb-ft @ 4,000 rpm
Electric motor: Permanent magnet synchronous motor
Electric motor power output: 80 hp/153 lb-ft torque
Hybrid system net horsepower: 134 hp
Emission rating: SULEV (with AT-PZEV)
Electronically controlled continuously variable transmission
Drive System: Front-wheel-drive
Hybrid battery pack: Nickel-metal hydride
Estimated fuel economy: 50 mpg (combined)*
DIMENSIONS (inches)
Overall Length: 175.6
Overall Width: 68.7
Overall Height: 58.7
Wheelbase: 106.3
Ground clearance: 5.5
Coefficient of Drag: 0.25
Wheels: 15-inch alloy wheels
17-inch alloy wheels (optional)
Tire Size: 15-inch: 195/65R15
17-inch: 215/45R17 (optional)
Seating Capacity: 5
EPA class rating: Midsize
* Preliminary figure based on Toyota's internal testing. Actual mileage will vary.

It might look ugly but this 1992 Honda Civic has double the fuel mileage of a standard Civic simply by lowering the coefficient of drag (Cd) from 0.34 to 0.17 with a little engineering savvy and $400 worth of material bought the local hardware store. In fact the drag on this 350,000 miles (563,270 km) old Civic has been reduced to the point where it is virtually equal to the radical tear drop shaped Aptera which has a Cd of 0.15.

The car's builder Mike Turner says at a highway speed of 65 mph (105 km/h) he can routinely achieve a fuel mileage of 95 MPG (2.5Lt per 100km). The most obvious feature are the wheel covers and Boat Tail which were modeled on a Vintage German 1939 Maybach. The extended tail eliminates the recirculating, low-pressure eddy that forms behind "normal" cars and that act to slow them down. More subtle but just as important additions have been a fully enclosed undertray, the removal of wing mirrors and blocking intake vents at the front of the car and exhausting the radiator air out through the front wheel wells.

Using coast down tests and a SuperMID fuel consumption computer Mike’s next target is to improve mileage during night driving as he has calculated the electrical load from the lights are costing him 2 to 3 mpg with half of this loss being from the parking lights. Mike wants to replace the parking and dome lights with LED's. Check out the Aero Civic web site.

Video featuring a Raser modified Hummer H3 converted to Series Hybrid that they claim gets 100mpg in EV only mode. Read More

A British produced documentary featuring interviews with former EV1 and Tesla research engineer Wally Rippel and test drives of both the pre-launch Tesla Roadster and the Wrightspeed X1 with Ian Wright.

I piani di Fiat per la creazione di un maxi-polo dell'auto con Chrysler e Opel "hanno incontrato gravi opposizioni politiche, ma ciò non vuol dire che l'operazione non riuscirà". E' quanto si legge sulla Lex Column del Financial Times. Tra le opzioni all'orizzonte di Opel, sottolinea il quotidiano, c'è il fallimento ma "con le elezioni a settembre, potrebbe essere un suicidio politico per la coalizione al governo". D'altronde, l'esecutivo tedesco non intende entrare in campo: l'unica altra offerta industriale sembra essere quella di Magna, con le russe Gaz e Sberbank: un'operazione la cui "logica commerciale appare vaga". Resta l'interesse da parte di fondi sovrani e gruppi di private equity ma una vendita del genere sarebbe "politicamente delicata per il Governo di Berlino". E infine c'è Fiat: che "può non essere il salvatore ideale, dal momento che è uscita dal recente salvataggio gravata da 5,9 miliardi di debiti". Tuttavia "l'a.d. Sergio Marchionne ha piani credibili per risparmiare 1 miliardo l'anno con la condivisione di piattaforme e motori con Opel. Inoltre parla con una sincerità persuasiva del futuro ridimensionato che attende l'industria dell'auto". La Gran Bretagna, sottolinea il FT, "sembra preoccupata meno da Fiat che dai tentativi tedeschi di salvaguardare le proprie fabbriche alle spese degli impianti di GM in altri Paesi, tra cui le due fabbriche di Vauxhall. L'Italia ha simili preoccupazioni. Tuttavia tutti devono entrare in gioco, dal momento che il piano di Fiat fa affidamento su prestiti pubblici. In fondo, tutti sanno che se non si riesce a raggiungere un accordo si andrebbe verso la chiusura di tutti gli impianti europei di GM".
(Fonte: www.ft.com - 11/5/2009)

Thermoelectrics - the phenomena in which a temperature difference creates an electric potential - have been known about for almost 200 years, but practical applications have not been widespread due to their low energy efficiency. That may all now be about to change as Germany automakers Volkswagen and BMW have developed thermoelectric generators (TEG) that recover waste heat from a combustion engine.

According to a report by Prof. Rowe of the University of Wales in the International Thermoelectric Society, Volkswagen claims 600W output from the TEG under highway driving condition. The TEG-produced electricity meets around 30% of the car’s electrical requirements, resulting in a reduced mechanical load (alternator) and a reduction in fuel consumption of more than 5%.

BMW and DLR (German Aerospace) have also developed an exhaust powered thermoelectric generator that achieves 200 W maximum and has been used successfully for more than 12,000-km road use.

Thermoelectric refrigeration

Thermoelectric have been used for refrigeration utilizing the Peltier effect originally discovered in 1834. An electrical current at the junction of two different metals results in heat being absorbed by one metal and expelled by the other metal. Thermoelectrics can also be used to generate electricity using the Seebeck effect that dates back to 1770. Thermoelectric power generators convert heat energy to electricity. When a temperature gradient is created across the thermoelectric device, a DC voltage develops across the terminals.

Thermoelectric generators

Typical applications for this technology include providing power for remote telecommunications and navigation beacons. A more familiar application is a thermocouple that is a type of temperature sensor that can generate a current proportional to the amount of heat it is exposed to. Thermocouples were used in remote parts of Russian in the 1920s to power radios from a wood fireplace and they also form the basis of radioisotope thermoelectric generators (RTG) that use heat from a radioactive material to power deep space satellites. The drawback to all thermocouple based electric generation is that they are very inefficient at between 3-7%.

Automotive thermoelectric generators (ATEG) have been developed intermittently since 1988 when Porsche made a exhaust ATEG capable of 20-30 watts out of a 944 exhaust system but they have never made it past the prototype stage of development.

"Sergio Marchionne, il nuovo mago dell'auto" titola il supplemento economia del quotidiano francese Le Figaro, che oggi dedica ampio spazio alla "Fiat che si ritaglia un impero a tappe forzate". Nel ritratto dedicato all'amministratore delegato dell'azienda torinese, Le Figaro-Economie scrive che John Elkann, interrogato su Marchionne, ha detto che "la famiglia Agnelli ha piena fiducia" in lui e nella sua "straordinaria capacità di sintetizzare e affrontare situazioni complesse. Le sue soluzioni - aggiunge Elkann - sono sempre razionali, pur comprendendo una grande creatività".
(Fonte: www.lefigaro.fr - 11/5/2009)

La soluzione migliore per il futuro di Opel e' una fusione con la Fiat. Lo scriveva abato scorso, in un editoriale dal titolo "Meglio Fiat che niente", la progressista Sueddeutsche Zeitung (SZ), il maggiore quotidiano nazionale, secondo il quale "il fuoco di sbarramento con cui viene attualmente salutata la Fiat in Germania è inappropriato, forse addirittura pericoloso". Il giornale di Monaco di Baviera definisce "colposo" l'atteggiamento di rifiuto nei confronti del Lingotto mostrato finora dal management della casa di Ruesselsheim, dal governatore della Renania-Palatinato, Kurt Beck, e dagli altri responsabili socialdemocratici, poiché "finora non esiste alcuna alternativa seria ad un investitore come la Fiat". A giudizio della SZ, il mondo politico tedesco e i dipendenti Opel "dovrebbero mostrare un atteggiamento costruttivo e sostenere Fiat, invece di far blocco ed insistere sulla difesa dei posti di lavoro", poiché sarebbe "ingenuo" credere che chiunque sia l'investitore che alla fine la spunterà, "non verranno chiuse nè fabbriche, nè ridotti gli organici". Il giornale sottolinea che già la GM ha stimato al 30 per cento la sovrapproduzione. La conclusione della Sueddeutsche è che il Lingotto "ha successo con la sua Cinquecento ed è questo ciò che manca ad Opel: un design originale che piaccia anche alla clientela".
(Fonte: www.sueddeutsche.de - 9/5/2009)