_{Fuel Economy Comparison1}

Test Loop Speed Conventional Manifold PRV Manifold Percent Improvement City Variable 38 mpg2 42 mpg2 11% Highway 65 mph 43 mpg3 53 mpg4 23% Highway 65 mph 43 mpg3 58 mpg5 35%

Notes

1. No mechanical changes between tests other than the induction system and associated fuel map. Highway tests conducted on a closed-circuit test loop between Denver, CO and Brush, CO at 65 mph -- the same test used since June 2007. Honda D15B engine and low rolling resistance Sumitomo tires.
2. Average of seven 200-mile test loops. Throttle control improvement is expected to increase fuel economy and future designs.
3. Air/fuel ratio is stoichiometric, closed-loop control O2 sensor feedback control using a stock P08 electronic control unit. Test repeated three times with a range of 42 to 44 miles per gallon in ideal fair weather conditions with light wind.
4. Air/fuel ratio is stoichiometric, closed-loop control O2 sensor feedback control using a AEM electronic control unit.
5. Air/fuel ratio is 16.8, closed-loop control O2 sensor feedback control using a AEM electronic control unit.
6. Explanation for the improved fuel economy can be found by clicking here.
7. A simple analogy comparing engine and human respiration can be found here.