Hybrid vehicles and plug-in hybrid cars aren't quite living up to their manufacturer's fuel efficiency claims, a new Consumer NZ investigation has found.
The non-profit organisation found that among the 10 cars it tested, on average, plug-in-hybrids (PHEVs) used 73% more fuel than claimed, while standard hybrids averaged 20% more.
For a week, Consumer NZ tested the cars against their manufacturing claims by driving them around Wellington along the same route in rush hour traffic, as well as a supermarket run. It also tested a longer weekend trip over the Remutaka Hill.
Researcher James le Page told 1News while some variation was not unexpected it was "staggering" to see how big it was in some cases.
"The [manufacturer] claims they put out there are all based on laboratory testing; in the real world, you would expect a little bit over... but 73% over, those are big numbers.
"It's good information for consumers to know that you're probably not going to get what they say you are going to get, especially if you do long road trips in plug-in-hybrids."
Among the five PHEVs tested, the Kia Niro used more than double (163%) the 0.8L/100km that its manufacturer claimed. Meanwhile, the Hyundai Ioniq used up 92% more than the 1.2L/100km it was estimated to use.
When it came to fully hybrid vehicles, the commonly used Toyota Yaris ZR saw the biggest discrepancy — up 44% of the 3.6L/100km it was estimated to use.
Toyota told 1News that its fuel consumption figures are based on tests done under controlled conditions and that real world figures will differ as a result of how the vehicle is used, weather conditions and the driver.
MG declined to comment, instead referring 1News to the AA.
The other manufacturers that supplied their cars to Consumer NZ for testing are aware of the report's findings. Each was independently contacted by 1News but did not respond to a request for comment by deadline.
The AA's Allister Wade said it's important to choose a car based on your needs when looking to purchase a vehicle.
"It comes down to the environment, how you use it, and what sort of distances you are going to be driving in."
He said that drivers that go with a hybrid should keep their travel within reach of a charging point in order to keep fuel consumption down.