With Ducati having elected to switch to racing as an Open entry in the MotoGP class, it is time for a quick refresher course on the rules. Below is a primer on the key differences between racing as an Open entry and racing as a Factory Option entry, and the advantages and disadvantages of each. Factory Option bikes have 20 liters of fuel, and 5 engines to last the season. No engine development is allowed, the engine specifications being frozen before the first race in Qatar. Factories have to supply template engines with specifications of all parts at the race, those parts must remain unchanged. Development is frozen on parts not accessible when engine is sealed. In short, this means engine internals, crankshaft, crankcases, cams, valves, pistons, conrods, etc.