Horse outward similarity is an unreliable measure of relatedness. Besides the horse, there are six other species of genus "Equus" in the Equidae family. These are the ass or donkey, "Equus asinus"; the mountain zebra, "Equus zebra"; plains zebra, "Equus quagga"; Grévy's zebra, "Equus grevyi"; the kiang, "Equus kiang"; and the onager, "Equus hemionus". Horses can crossbreed with other members of their genus. The most common hybrid is the mule, a cross between a "jack" (male donkey) and a mare. A related hybrid, a hinny, is a cross between a stallion and a jenny (female donkey). Other hybrids include the zorse,
Hyundai Equus wheelbase, and a different engine. The VI is based on an all-new platform, that has been entirely developed by Hyundai Motor Corporation. Although the car has nothing in common with the previous Equus, the VI takes only the name from old Equus, because the name 'Equus' has prestige in Korea. The Korean domestic market Equus comes as a 3.8L "Prime" and a 4.6L "Prestige" in South Korea. It is the most expensive model in the company's lineup. It launched in the People's Republic of China in August 2009. The Hyundai Equus was listed in the '10 exciting cars for 2010'