MEXICO CITY (Reuters) - Red Bull's Daniel Ricciardo and Toro Rosso's Brendon Hartley both collected penalties for Sunday's Mexican Grand Prix, taking the total tally of drivers penalized to five on a confusing grid.
Australian Ricciardo, who qualified seventh, was given a 20-place drop after the team replaced the engine and elements of the power unit.
New Zealander Hartley, 13th fastest in Saturday's qualifying for his second race, also collected a 20-place demotion for similar reasons.
They join Toro Rosso's Pierre Gasly, who was due to start last after being sidelined in qualifying and had a meaningless additional 20-place drop imposed, and McLaren's Fernando Alonso and Stoffel Vandoorne among those penalized.
Vandoorne has a 35-place drop and Alonso 20.
Although there are only 20 grid slots, the order in which the penalties are applied leads to confusing situations with Ricciardo actually expected to start 16th.
Ferrari's Sebastian Vettel is on pole with Mercedes's championship leader Lewis Hamilton lining up third. Hamilton need only finish fifth to secure his fourth world title.
(Reporting by Alan Baldwin, editing by Clare Fallon)