Toro Rosso's Carlos Sainz and Daniil Kvyat have called for Formula One to address inconsistencies when deciding whether drivers get penalties during grands prix.
F1's officiating has come under fire this year regarding the amount of regulations being put in place over track limits and wheel-to-wheel racing. Both Toro Rosso drivers were penalised in separate incidents at the Mexican Grand Prix, with Sainz handed a five-second time penalty for forcing Fernando Alonso off-track at the start of the race. Sainz insists he has seen similar incidents go unpunished.
"I've seen less [penalties] for more," the Spaniard said. "I heard that [in Mexico] there were very similar situations with mine and Fernando's incident and that there were no penalties. This is what Formula One needs to understand, either to look at it incident by incident or to put a fixed rule.
"Nowadays it's difficult to know what will happen to you if you do a certain move that is a tiny bit on the limit. It's a bit of a lottery to get a penalty or not. Us drivers need to race with a very clear thing in mind when we overtake a guy."
F1's current judicial system sees three FIA-appointed representatives adjudicating on each grand prix, including an experienced former driver. An additional steward is nominated by the National Sporting Authority of the country holding the race. However the panel is not permanent, something Sainz feels should be changed.
"I've said [F1 should have fixed stewards] my whole Formula 1 career. It's understandable -- humans are humans -- you will have a different opinion to me, so every race there will be very different opinions.
"At the moment we never know what to expect about a move or after an accident After seeing Fernando on the grass in Mexico do they give me a penalty or do they think it was a great move? [With fixed stewards] probably the criteria will be a lot closer every weekend."
Kvyat was also hit with a five-second penalty for being adjudged to have left the track when overtaking Romain Grosjean, and joined his teammate in criticising F1's decision-making process.
"They are really inconsistent these guys," Kvyat said. "I'm very unhappy with how they make the decisions to be honest. There's really no consistency, no anything. Massa and Alonso in Austin, and me and Grosjean here -- a completely different reaction. I disagree with that but I have no influence in this anymore."
When asked if he plans to bring up the debate at the drivers briefing in Brazil on Friday, the Russian replied: "To be honest I find it a bit boring to talk about this, it's a big waste of time. Everybody is talking about it and, what is the result? They still do the same.
"In those briefings, they talk, talk, talk, I don't want to waste my time for this because they are going to do their own thing anyway. Honestly I don't have a clear clue on how they should do these things. Gravel traps is a good solution, like someone suggested I think."