Ford Motor Co. enters the luxury hybrid-electric-vehicle market with its new ’11 Lincoln MKZ Hybrid midsize sedan, but it remains to be seen whether the model will fare better than its competitors.

Ford does not provide volume projections for the ’11 Lincoln MKZ Hybrid, unveiled today at the New York auto show, but a Ward’s analysis shows sales will be tough to come by, as indicated by a handful of luxury auto makers that have had limited success with HEVs.

The top-selling luxury hybrid, Toyota Motor Corp.’s Lexus HS 250h, has delivered 8,658 units since its introduction in August 2009, according to Ward’s data.

That tally represents 27.7% of all Lexus IS 250 and IS 350 models sold in the timeframe, the highest number of hybrids delivered on a percentage basis among luxury offerings.

The Cadillac Escalade Hybrid SUV is runner-up to the Lexus HS 250h on a percentage basis of total Escalade units sold, with the hybrid version accounting for 23.2% of all deliveries.

However, the percentage total is deceiving, as it’s based on lower volume. Cadillac Escalade Hybrid sales have totaled only 1,945 since August 2009, Ward’s data shows.

Besides the Escalade, Lexus is the only other maker offering luxury hybrids, with a model lineup including the GS 450h, LS 600h and RX 400h and 450h. Of those, only the RX models break double-digits as a percentage of total models sold, with RX hybrids accounting for 14.5% of all RX deliveries.

According to a Ward’s analysis, Lincoln this year will deliver 27,000 MKZs, with hybrids making up about 4,000, or roughly 15% of the total.

Based on the performance of Toyota and General Motors Co.’s luxury hybrids, a 15% hybrid penetration for the MKZ would be modestly successful. But that success may be fleeting, as an influx of luxury hybrid competitors are on the way.

In the ’11 model year, five more offerings are expected to enter the segment, including the Infiniti M-Series Hybrid and the Chevrolet Volt extended range hybrid, which falls under Ward’s “Luxury Regular” segmentation. By the ’16 model year, some 20 luxury hybrids will be offered in the U.S.

Ford has little to lose by launching the ’11 Lincoln MKZ Hybrid, as it shares a powertrain with its sister vehicles, the Ford Fusion and Mercury Milan Hybrids, says Erich Merkle, president of Autoconomy in Grand Rapids, MI.

“It’s cost effective, and leveraging the technology between the brands makes sense,” he says. “And from an image perspective, it helps convey the image of fuel efficiency and being environmentally conscious.”

Ford says the MKZ Hybrid achieves 41 mpg (5.7 L/100 km) in city driving, besting its nearest competitor, the ’10 Lexus HS 250h, by 6 mpg (2.6 km/L).

Like the Fusion and Milan hybrids, the MKZ utilizes new nickel-metal-hydride “traction” battery cells in its packs, which are lighter and generate 20% more power than those used in Ford’s previous-generation Escape and Mariner cross/utility vehicle hybrids.

The MKZ battery packs are tucked neatly behind the rear seat to conserve valuable cabin room. Trunk space is only slightly compromised: 11.8 cu.-ft. (0.3 cu.-m) for the hybrid model vs. the 16.5 cu.-ft. (0.5 cu.-m) in the gas-powered model.

The battery powers a 275-volt, permanent-magnet AC synchronous motor that produces 106 hp. The MKZ’s gas engine also receives an upgrade over previous iterations.

The new 2.5L inline 4-cyl. engine produces 155 hp and 136 lb.-ft. (184 Nm) of peak torque and is mated to an electronically controlled continuously variable transmission.

Ford says its hybrid powertrain configuration allows the MKZ to accelerate to 47 mph (76 km/h) in pure-electric mode, noting the Lexus HS 250h only reaches 25 mph (40 km/h) in battery-only mode.

While the MKZ Hybrid will have much in common with the Fusion and Milan Hybrids, there are subtle differences.

Like the SmartGauge with EcoGuide technology found on the Fusion and Milan, the MKZ’s display shows a graphical representation of vines, which grow leaves when the vehicle is driven in a fuel-efficient manner. When a decrease in fuel efficiency is detected, the leaves wither and fall off the vines.

But the MKZ adds white flowers to the vines, which remain permanent unless the long-term fuel economy is reset. The display also provides real-time information about the powertrain to help drivers maximize fuel efficiency.

The exterior of the MKZ Hybrid will be identical to the gas-powered model, with the exception of a small hybrid badge. Pricing is expected to be announced closer to the vehicle’s scheduled fall launch.