The fourth passenger-car resizing program at General Motors has produced the most dramatic new models in recent U. S. automotive history. The program involved GM's ″X″ body cars - the Buick Skylark, Oldsmobile Omega, Pontiac Phoenix, and Chevrolet Nova (renamed Citation). The new models have front-wheel drive, with the engine/transmission mounted transversely. The transverse powertrain layout is largely responsible for increasing interior space and reducing overall length of the vehicles. A 151-cu in. , inline, 4-cyl engine built by Pontaic is standard on all models.