_{Fuel Economy Comparison1}

Test Speed Conventional Manifold PRV Manifold Fuel Economy Improvement City Variable 38 mpg2 42 mpg2 11% Highway 65 mph 43 mpg3 53 mpg4 23% Highway 65 mph 43 mpg3 58 mpg5 35% Air Care Colorado Variable (city) 32.1 mpg8 36.0 mpg8 12%

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 204-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.
8. Calculations are based on Environmental Protection Agency, 40 U.S.C. § 600 using results from State of Colorado tail pipe analysis.