If you can't get 100% electric, then getting to 95% electric is still a reasonable drop in emissions. Furthermore, PHEVs might have fewer greenhouse emissions over its lifetime than EVs: those Li-Ion batteries are pretty bad for the environment, and PHEVs use a fraction of them compared to pure electrics.
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Something like the Prius Prime, Rav4 Prime, Honda Clarity , or GM Volt will get you 50-miles per charge and 300-miles on gasoline.
Worst-case scenario, you have a gasoline engine (probably for 2-hour or 4-hour drives to the beach). Best case scenario (aka: most days), you leave your garage with 50-miles of electric range. Most PHEV owners suggest that they go months between gasoline fillups, often burning most gasoline to prevent stale fuel / maintenance purpose, rather than out of necessity. If your day-to-day is often within 50-miles between chargers (ex: 50-miles at home, and 50-miles from your work charger), you very well could cut out over 95% of your gasoline usage easily (with the remaining 5% the maintenance gasoline-burn offs)