The HybridCars.com monthly sales dashboard is a collaboration of HybridCars.com and Baum & Associates, a Michigan-based market research firm focusing on automotive issues including the hybrid and electric vehicle market.

The number of hybrid gas-electric cars sold in the U.S. declined from 34,000 in March to 25,000 in April, and to 16,000 in May. The drop by half in just two months is attributed to supply shortages for vehicles and related components due to the March earthquake in Japan. The lack of inventory, combined with rising demand due to high gas prices, lifted prices (when incentives evaporated). This caused some folks considering a hybrid to choose a less expensive model or postpone a purchase.

2011 Toyota Prius

Prius was in short supply in May. Sales of the most popular hybrid fell by 51 percent.

At the same time, general consumer confidence was shaken throughout the spring due to high gas prices. The overall auto market is down 4 percent compared to a year ago. Hybrids were hit even harder, taking a precipitous fall of 42.1 percent compared to 2010. As usual, the Toyota Prius dominates the market, with its 51 percent drop compared to a year ago pulling down the total hybrid market numbers.

There were similar, and even worse numbers, reported throughout the entire hybrid field—most notably a 78 percent fall in sales of the Toyota Highlander Hybrid and an 84 percent drop in sales of the Lexus HS 250h.

The supply disruption produced what will likely go down as one of the worst months for hybrid sales in recent years. The take-rate for hybrids fell to 1.5 percent.

Incentives in the overall market were down between $500 and $800 in May, and perhaps even more so for hybrids, since they are in such short supply.

On the plug-in front, sales of the Chevy Volt were modest this month—allowing the Nissan LEAF to catch up in total sales to date in the category. Some observers attribute low Volt sales to G.M.’s decision to hold off on customer sales to allow dealers to have demos for prospective customers, or simply to draw in traffic to the showroom where buyers might choose other vehicles.

Diesels escaped the supply disruption. As a result, sales of clean diesel vehicles continued to impress—up 34 percent compared to a year ago—with the Jetta TDI carrying the load in terms of volume.

We will keep a careful watch on hybrid sales when supply returns to normal. This will determine if demand has been affected by the easing of gas prices in the past few weeks.

May 2011 Hybrid Car Sales Numbers

Hybrids sold in the US (May 2011): 16,319
Hybrid Take-Rate: 1.54%

US hybrid sales for May 2011

Model Units vs. last month vs. May 2010 CYTD vs. CYTD 2010
Toyota Prius 6,924 -44.5% -51.4% 62,180 13.0%
Honda CR-Z 1,557 -14.4% n/a 7,046 n/a
Honda Insight 1,435 -45.7% -25.0% 10,137 15.6%
Ford Fusion 1,256 -2.3% -49.5% 6,355 -20.5%
Ford Escape 1,118 4.5% -14.1% 4,698 -3.4%
Lexus RX450h 610 -47.7% -55.1% 5,126 -10.7%
Toyota Camry 592 -46.7% -59.3% 4,922 -23.6%
Linc. MKZ Hybrid 561 11.5% n/a 2,444 n/a
Altima 499 49.4% 2,109 -40.9%
Lexus CT 200h 454 -48.1% n/a 3,528 n/a
Honda Civic 268 121.5% -62.6% 2,015 -19.9%
Lexus HS 250h 220 -21.1% -83.8% 1,198 -79.7%
Toy. Highlander 149 -60.8% -78.2% 2,722 -4.0%
Porsche Cayenne 114 6.5% n/a 688 n/a
Cad. Escalade 89 -23.9% -32.1% 518 -8.5%
Chevy Silverado 89 -13.6% -70.2% 525 -17.3%
GMC Yukon 77 -19.8% -60.1% 366 -40.4%
Chevy Tahoe 63 0.0% -73.9% 307 -58.8%
Mercedes S400 49 53.1% -51.5% 156 -66.2%
VW Touareg Hybrid 40 -23.1% n/a 261 n/a
BMW Hybrid 7 38 18.8% 442.9% 175 n/a
Infiniti M35h 36 -14.3 n/a 78 n/a
Mazda Tribute 35 -5.4% -42.6% 179 -31.9%
GMC Sierra 22 37.5% -42.1% 105 -57.3%
Lexus GS450h 18 -37.9% -52.6% 123 -21.7%
BMW X6 3 50.0% -75.0% 24 -75.3%
Chevy Malibu Hybrid 2 n/a -95.1% 2 -99.4%
Lexus LS600hL 1 -90.0% -87.5% 35 -27.1%
Mercedes ML450 0 -100.0% -100.0% 1 -99.8
All hybrids 16,319 -34.2% -42.1% 118,093 8.1
All vehicles 1,057,826 -8.4% -3.9% 5,260,999 13.9%

May 2011 Plug-in Electric Car Sales Numbers

Plug-in cars sold in the US (May 2011): 1,631
Plug-in Take-Rate: 0.15%

US plug-in electric sales for May 2011

Model Units vs. last month vs. May 2010 CYTD vs. CYTD 2010
Nissan LEAF 1,142 99.3% n/a 2,167 n/a
Chevrolet Volt 481 -2.4% n/a 2,184 n/a
Smart ED 8 -70.4% n/a 87 n/a
All plug-in cars 1,631 344.4% n/a 4,438 n/a
All vehicles 1,057,826 -8.4% -3.9% 5,260,000 13.9%

May 2011 Clean Diesel Car Sales Numbers

Clean Diesels sold in the US (May 2011): 9,138
Diesel Take-Rate: 0.79%

US clean diesel sales for May 2011

Model Units vs. last month vs. May 2010 CYTD vs. CYTD 2010
VW Jetta 5,409 -2.8% 24.4% 22,069 41.2%
Volkswagen Golf 977 2.0% 63.4% 4,025 86.3%
BMW X5 506 15.0% -18.3% 2,681 -17.7%
Mercedes GL320 446 4.2% 43.4% 1,960 62.4%
Audi A3 365 0.3% 54.0% 1,633 26.9
Audi Q7 340 -8.8% 55.3% 1,739 65.0%
VW Touareg 308 16.7% 158.8% 1,120 37.8%
Mercedes E320 270 9.8% 5,300.0% 1,148 2,633.3%
BMW 335d 265 17.8% 28.0% 1,231 3.6%
Mercedes ML320 259 7.9% 17.7% 1,270 61.8%
Mercedes R320 172 391.4% 1,128.6% 344 123.4%
Jeep Gr Cherokee n/a 100.0% 152 -66.3%
All clean diesels 9,317 2.0% 33.8% 39,372 40.5%
All vehicles 1,057,826 -8.4% -3.9% 5,260,999 13.9%