Yes, Jovian planets (Jupiter, Saturn, Uranus, and Neptune) generally have larger equatorial diameters than their polar diameters. This is due to their rapid rotation.

Here's why:

* Centrifugal force: As these planets spin quickly, they experience a strong centrifugal force at their equators, which pushes outward. This force counteracts the planet's gravity, causing the equator to bulge outwards and the poles to flatten slightly.

* Fluid nature: Jovian planets are primarily composed of gas and liquid, which are more easily deformed than solid rock. This makes them more susceptible to the effects of centrifugal force.

This phenomenon is known as oblateness and it's a characteristic feature of rotating gas giants.

For example, Jupiter's equatorial diameter is about 9% larger than its polar diameter. Similarly, Saturn has a significant bulge at its equator.

Therefore, the statement that Jovian planets have larger equatorial diameters is true.