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 engine types were changed to 3.3 and 3.8 Lambda V6 engine types which were designed and developed by Hyundai Motors. But the automatic transmission was not changed. Hyundai officially ceased the production of 1st generation Equus in November 2009. A new bigger, rear-wheel drive Equus was launched in March 2009. A limousine model was made for the Korean market. Equus Limousines have been used by famous company owners in Korea as well as foreign VIPs. The second generation Equus, codename "VI", was unveiled in Grand Hyatt Seoul. Unlike the old Equus, the VI has a rear-wheel drive architecture, a longer