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A 1991 Volvo model 960 equipped with an electrically heated catalytic converter system (EHC) was evaluated in multiple FTP tests with three different gasolines: current certification fuel, the Auto/Oil industry average fuel (RF-A), and a fuel that meets the 1996 California Phase II reformulated gasoline standards. Tests of each fuel were run with a low-mileage EHC located upstream of either a low-mileage stock main converter or a stock converter that had been road aged for 100,000 miles under European driving conditions. Test results with EHC operation showed significant variations in NMHC, CO, and NOX emissions with the three test fuels. NMHC emissions were 2-2.5 times lower for the Phase II fuel versus RF-A, with the certification fuel intermediate in NMHC emissions. Tests with the EHC/high-mileage converter system exhibited higher overall FTP emissions compared to the EHC/low-mileage main converter system, as expected.

A 1990 Olds Cutlass Calais with GM's Quad-4 engine was outfitted with a Camet® EHC system and tested for FTP emission performance after 4000 road miles. EHC operation on this vehicle reduced NMHC and CO F17P emissions by 77% and 67%, respectively, versus the vehicle's stock catalyst configuration. Absolute NHMC and CO FTP emissions were below California's ULEV 50,000 mile standards with EHC operation. EHC heating strategy tests showed that a post-engine start heating schedule was nearly as effective as a pre-start heating schedule in reducing cold start hydrocarbon and CO emissions. Tests comparing vehicle and emission performance with different engine control parameters indicated no change in EHC effectiveness with respect to cold start emissions for the two calibrations evaluated here.