Engine downsizing is the use of a smaller engine in a vehicle that provides the power of a larger one. It is the result of car manufacturers attempting to provide more efficient vehicles by adding modern technologies, for instance, turbochargers, direct injection and variable camshaft. The smaller engine is also lighter and provides torque and power with similar performance to a much larger engine. However, the downsizing technique may lead to undesirable vibration effects on the driveline, such as structural damaging, vibration fatigue failure and extra noise. All these issues are related to natural frequencies investigation and they are often determined through the finite element method together with experimental tests during the product development phase.This work presents the finite element method limitation for natural frequencies determination of automotive components and a possible solution for the issue.