The study compared insurance claims from 25 pairs of matching hybrid and non-hybrid vehicles, excluding the Prius which doesn’t have a conventionally powered version, and found those involving hybrids were up to 27% less likely to involve an injury claim.

By comparison, the report showed hybrids were more likely to injure pedestrians. Studying injury-only claims from 17 pairs of hybrid and non-hybrid vehicles, the HLDI said the frequency of pedestrian injuries was 20% higher for hybrids.

HLDI vice predisdent Matt Moore, who conducted the study, said he accepted the results could be influenced by driver behavior, and that there was a chance that limited data meant not all of the injury-only claims involved pedestrians, but added that it was a sign American motorists could downsize fuel costs without affecting safety.

‘Weight is a big factor. Hybrids on average are 10 percent heavier than their standard counterparts. This extra mass gives them an advantage in crashes that their conventional twins don't have,’ he said.

But, he added: ‘When hybrids operate in electric-only mode pedestrians can't hear them approaching, so they might step out into the roadway without checking first to see what's coming.’