For pre Aug. 2006 Sonata with the 3.3L V6 the crankshaft pulley on the 3.8L Gen is the same as ours according to Hyundai P/N's. So the light weight Gen pulley from the 3.8L should work just fine. However after Aug. 2006 the Sonata has a different pulley on the V6 and its a different P/N then the early ones and the Gens. I am not sure the differences. I do have an early 06 so I ordered the 3.8L gen lightweight crank pulley and I will let you know how it works out.