Formula 1 risks turning itself in to a fuel-saving 'mess' in 2017 if the current 100kg allowance is not increased for the arrival of faster and heavier cars, warns Renault tech chief Nick Chester.
The move to the new turbo hybrid regulations in 2014 was aimed at helping F1 deliver an environmentally-friendly message – with cars running around 40% less fuel than they did in the V8 era.
However, plans for higher-downforce cars next year, which will also be heavier, has prompted concerns that F1 is going to need to rethink the 100kg limit that has been in place.
Estimates that teams have put together suggest fuel demands could increase by around 10 percent with the new cars – which could lead to most of the grid needing to conduct a massive amount of fuel saving.
Although teams bosses have not yet agreed on changing the rules, Renault technical director Nick Chester thinks it important change is made – otherwise the racing spectacle could suffer dramatically.
When asked by Motorsport.com what would happen if the 100kg limit stayed, Chester said: "I think it will be a mess.
"At the [recent] tech regulations meeting, we voted to get rid of the race fuel limit.
"We still have the flow limit, so you have a green message that the cars cannot consume too much, but abolishing the fuel limit will get rid of lift and coast and having to manage fuel, which seems like a good thing for racing.
"If we stay at 100kg and go to the 2017 regulations then there will be a lot of fuel saving, and I think people will start complaining about it."
As well as the 2017 cars being heavier, because of the addition of the closed cockpit Halo device, the increase in downforce will likely mean drivers will be pushing their engines harder.
Chester says calculations prepared by teams shows a decent amount more fuel will be needed.
"The team consensus is around 10kg, because the percentage of full throttle goes up enormously with the 2017 regs," he said. "So you will burn up more fuel.
"[Mercedes] didn't have to run 100kg all the time [last year]. Anybody can manage it, but I think even they would have to get fuel saving."
Following discussions about the matter at the Strategy Group earlier this month, there is no indication yet that all teams will agree to the plan.
For while those manufacturers like Honda and Renault that are less efficient are hugely in favour of the change, the pace-setting Mercedes outfit is wary about the impact of giving its rival freedom on fuel limits.
Talks will carry on between now and an April 30 deadline to try to find agreement.
Chester thinks that allowing more freedom on fuel limit would be a good way of helping close up the performance of the manufacturers.
"There is a big push to help power unit convergence and there is one way that could help a lot, which is getting rid of the race fuel allowance," he said.