Recently Graz University of Technology released a study of three Plug-in Hybrid Electric Vehicles (PHEV) available in Europe. They used a portable emissions tester and drove them in different tests while measuring their gas emissions: https://www.transportenvironment.org/wp-content/uploads/2023/02/2023_02_TE_PHEV_Testing_2022_TU_Graz_report_final.pdf A common architecture of the study test vehicles were multi-speed, automatic transmissions. This suggests a gas car had an electric motor and battery added ... not a clean sheet design. In contrast, my former 2014 BMW i3-REx is a serial hybrid with very small engine drove only a generator. EV range was a key metric: 115 km (72 mi) - 2014 BMW i3-REx 33.6 km (21 mi) - Peugeot 308 49.1 km (31 mi) - Renault Megane 41.2 km (26 mi) - BMW 330e xDrive 40 km (25 mi) - 2017 Prius Prime Electric motors are integral to the Prius, plug-in or not. Sad to say, the small battery limited the 2017 Prius EV utility compared to the 2014 BMW i3-REx. Regardless, the paper mostly dealt with the poor emissions of the three test PHEV. One effect of limited EV range was the engine has to more frequently go through cold-start warm-up. This is the most polluting mode because the catalytic converter has to reach operating temperature before working. Bob Wilson
Having already made the concession to lower emissions, my phev priorities are size, cost and range. Same for bevs. So far, I haven’t seen an improvement over my ten year old pip
Isn't the Prius a Partial Zero Emission Vehicle? Partial Zero Emission Vehicle (PZEV): Everything You Need to Know (caranddriver.com) Toyota Prius (2016-2021) MPG & CO2 emissions | DrivingElectric May want to recheck their criteria and testing methods their results make no sense. Example I can get any results I want with our Hyundai Santa Fe SEL. Driving on long trips at rural highway speeds I average right at 30 mpg. However, two weeks ago going to the grocery that is 3 miles away on a 20-degree morning I averaged 8 mpg for my going and return trip. So ask me my efficiency I can make it give you just about any number we want by rigging the test. One cravat - some PHEV's use the engine to make heat for the vehicle - they are ready to rock and roll at any time with car engine at somewhat normal coolant temperature at all times. The excess charge developed from running the engine is then used to charge the battery - so - minimal to no range loss due to cold weather - quite unlike the range loss experienced by all electric vehicles in this circumstance. Electric vehicles lose up to 30% range when temperatures dip below freezing, study finds | CBC News Maybe all vehicles have their strengths and weaknesses that need to be taken into consideration when picking the best vehicle for your lifestyle.
Series hybrid is fine on a PHEV with a long EV range, but can be an efficiency sapping system for shorter EV ranges. The BMW has 22 miles by the EPA. The other two are in the 30 to 40 mile range by WLTP. A ground up design will yield a better package of a car, but a shorter EV range 'conversion' of a traditional car model can allow lower cost entry for people to plug ins. There are ICE models that are PZEV. It is just a CARB or EPA designation for having very low emissions; better than SULEV. AT- to the front is used for clean hybrids. Has anyone done on road emission testing of the Prius, and published them? The ones in the link are the official ratings off a dynanometer. I think WLTP has an on road test segment, but it might be to just confirm the lab numbers weren't cheated. The paper gave the routes they drove, but left out things like speeds and traffic.