History: The Clean Air Car Race

Transcontinental Clean Car Races of Old

1968 - Great Electric Car Race

Cars from MIT and Caltech depart their own campus, racing for the other's campus. The MIT car made it first, but was penalized for towing their car 37 hours, giving the win to Caltech by 30 minutes, which made the race in 10 days. The route from Cambridge to Pasadena was 3,490 miles and was made using 53 recharging stations set up about 60 miles apart. The cars both used 50kW onboard chargers, and electric motors from Electric Fuel Propulsion, Inc.(EFP). EFP handled the logistics of the race and charging stations.

MIT's NiCd batteries from Gulton Industries cost $20,000 ($122,000 in 2008 dollars), at 75 Ah and 100VDC (7.5 kWh). To keep the batteries cool, students poured ice over them during charging and driving. MIT's custom built motor wasn't ready in time, so they used a conventional DC brushed motor instead (that motor later appeared in MIT's hybrid in the 1970 race). Caltech's conventional batteries cost $600. MIT's car got ~500 wH/mi at 53mph. The first iteration of their electrically commutated motor weighed 80 pounds, run by 120 pounds of electronics. Much of the battery woes were caused by poorly balanced batteries, causing the fuller ones to drain into the less full ones, wasting energy and heating the batteries.

Battery ChemistryNiCdLiFePo4
Battery Price$17,600 ($104,000 in 2007)$40,000
Battery Capacity7.5 kWh23 kWh
Battery Weight2000 lbs23 kWh
Charge Distance Record86 mi123 mi
Battery Capacity Cost$13,900 / kWh$1,700 / kWh
Charge Time10 Minutes2.5 Hours
Base Vehicle1968 Corvair1976 Porsche 914
Motor15 hp58 hp


1970 - Clean Air Car Race

Intercollegiate race with over 50 cars of a variety of powerplants, starting at MIT and ending in Caltech. The primary constraint was meeting the 1975 exhaust emission standards. Scoring was based on emissions, performance, and elapsed time. Performance score included noise. Vehicles included battery-electric, hybrid, steam, turbine, and ICE's buring LP, ethanol, and gasoline.

CalTech introduced regenerative braking on their vehicle. Boston's Electric Car Club (mostly employees of Anderson Power Products, inc.) introduced battery swapping, with a chase vehicle charging a second battery pack as they drive. Toronto University introduced a parallel hybrid design remarkably similar in concept to a modern Prius (minus the CVT). MIT's EV from 1968 became a series hybrid, with their 100-hp electrically commutated motor finally ready, a 30-hp Kohler propane engine coupled to a 12-phase 100V 120A silicon-rectified alternator. Another MIT hybrid ran a 136-hp gas turbine at 40,800 rpm to output 80 kW of electricity, powering a 600-hp motor from Inland Motors.

Requirements included:

  • Have at least 4 wheels
  • Carry at least two 170-lb people in an enclosed compartment
  • Meet all inspection and registration requirements of its state
  • Travel at least 60 miles at a minimum speed of 45 mph over nearly level terrain without refueling
  • Accelerate from 0 to 45 mph in 10? seconds or less
  • Meet 1975 California emissions standards
  • Meet 1970 National Bureau of Vehicle Safety Regulations


1972 - Urban Vehicle Design Competition

Started 9 Aug, decendent of Clean Air Car Race. Not a cross-country race, this was the start of the trend in hyper-efficient vehicle design toward very small, city only cars.