Expect more Sonata Hybrids, Hyundai’s first U.S.-market hybrid-electric vehicle, to arrive in showrooms by late April, while its Kia twin, the Optima Hybrid, will go on sale five months later than planned.

The Sonata Hybrid, which had been promised in large numbers this month, has been on sale since December. But dealers have received few.

Despite a March marketing push tied to NCAA basketball telecasts, “no one has them,” one retailer tells Ward’s, requesting anonymity.

Hyundai says Sonata Hybrid shipments are delayed because the auto maker is removing a switch that can disable a noisemaker designed to warn blind pedestrians.

The delay occurs against a backdrop of critical reviews in cooler climates. Media outlets, including Ward’s, observed fuel economy well below its U.S.

Environmental Protection Agency city/highway rating of 36/40 mpg (6.5-5.9 L/100 km).

Hyundai adamantly denies any performance problems. “The slow rollout has nothing to do with some of the early results that folks got,” spokesman Jim Trainor says.

“Even with the early prototypes that were making the rounds last fall (in California), many media got well over 40 mpg on the drive,” Trainor says, adding “production units will be better.”

Cold temperatures can negatively affect the performance of battery-powered vehicles.

The Sonata Hybrid’s noisemaker is deemed necessary because HEVs and electric vehicles are so quiet pedestrians, especially those with impaired vision, can’t easily detect their presence.

A bill signed by President Obama in January mandates the feature for U.S. HEVs and EVs, but the U.S. National Highway Traffic Safety Admin. has yet to study equipment such as on/off switches, let alone issue a timetable for compliance.

Rival Nissan’s Leaf EV, now on sale in the U.S., is equipped with an on/off switch.

By the end of next month, “you’ll start to see the pipeline filling pretty quickly,” Trainor says of Sonata Hybrid availability. Some 900 Sonata Hybrids are now at port in the U.S., while 650 are in transit from Korea.

Another dealer who requested anonymity tells Ward’s Hyundai has been suggesting delivery is imminent “for the last six months.”

Hyundai is mum on official sales numbers, bucking the industry norm for hybrid sales reporting.

Hardin Hyundai of Anaheim, CA, which bills itself as the largest Hyundai dealer in Southern California, has sold two, a salesman tells Ward’s.

Meanwhile, the Optima Hybrid now is set to go on sale late in the second quarter. It had been scheduled for a January sales launch, one month after the Sonata Hybrid.

Michael Sprague, Kia Motors America vice president-marketing, tells Ward’s Hyundai-Kia headquarters in Korea want the Sonata Hybrid to bow first.