General Motors has delayed indefinitely the Chevrolet Camaro convertible and Z28 high-performance variant to save cash, sources say.

GM also has tabled plans to add a four-cylinder engine version of the Camaro. GM is starting to ship the Camaro to dealers this week.

Insiders say executives hope to restore the convertible to GM's product plan. GM originally had wanted to launch a convertible in 2010 and bring out the Z28 soon afterward.

"Neither one has been outright canceled," says Terry Rhadigan, a Chevrolet spokesman. Rhadigan said GM will seek to bring out the convertible in 2011.

The Z28 was to have challenged two rival performance muscle cars--the Shelby GT500 version of the Ford Mustang and Dodge's Challenger SRT8.

Plans for a four-cylinder engine for the Camaro lost appeal as gasoline prices dipped and the Camaro scored well on federal fuel-economy tests.

Last year, Vice Chairman Bob Lutz said GM was considering the same four-cylinder engine for the Camaro that GM uses in the Pontiac Solstice and Saturn Sky roadsters. The 2.0-liter turbocharged direct-injection engine is rated at 260 hp in those cars.

Gene Stefanyshyn, GM's vehicle line executive for performance cars, said cheaper gasoline played a role in shelving the smaller engine.

"We're looking at it. We don't have anything approved," Stefanyshyn said at a press event last week. "But with gas $1.78 a gallon, we have to weigh where we put our poker chips."

Another source familiar with GM product plans confirmed that the four-cylinder for the Camaro is dead for "the time being."

Not only have fuel prices leveled out, but GM surpassed its own estimated highway mileage rating of 27 mpg for the V6 Camaro. The EPA last week rated that vehicle at 29 mpg in highway driving.

The strong fuel-economy performance of the 3.6-liter, 304-hp V6 reduces the need to offer a four-cylinder engine, sources say.

GM also offers a 6.2-liter V8 in two versions, making 400 hp and 426 hp.

GM began building the Camaro, which starts at $22,995, including shipping, on March 16. GM estimates that it will take until May or June to fill the 14,000 sold orders in hand.

Chevrolet Camaro convertible reportedly back on, albeit running late

The on again, off again roller coaster ride that is General Motors' product development schedule once again apparently has a green light; the 2010 Chevrolet Camaro convertible. The drop-top Camaro is once again scheduled for a 2011 grand entrance, one year after the first Bowtie pony cars begin rolling off the line in Oshawa. Motor Trend reported back in November that the convertible Camaro was in trouble due to GM's cash crunch, and last week we learned from The Detroit Bureau that financial problems at a German supplier for the car's roof was threating the model's timetable. For its part, General Motors insists that the topless Camaro has always been scheduled for one year after the coupe began production, but now Motor Trend is now saying that the Camaro Convertible will probably not arrive until the first quarter of 2011 (likely as a 2012 model).

With a reported 14,000 pre-orders already on the books for the fixed-roof Camaro, GM is looking at some much needed good news in the short term. To better compete with Ford's Mustang and Dodge's Challenger, though, the General will need to make good on a ragtop variant (and perhaps a Z28, although that looks unlikely to happen). If MT's reports are accurate, the gap between coupe and convertible models is likely to be well over a year, which will be a tough pill for sunlovers to swallow. However, if the production model looks as good as the concept shown above, the Camaro could have all the inertia it needs when the top comes down.