F1 bosses give themselves until end of May to agree on new engine rules
Formula 1 bosses have given themselves just over six weeks to agree on new engine rules for the 2021 season.
Governing body the FIA reiterated at two meetings of senior figures on Tuesday its desire to introduce simplified versions of the current 1.6-litre turbo hybrids.
It has set a deadline of the end of May to finalise the new rules, which have yet to be agreed by manufacturers.
So far, the four car companies who make engines have rejected the FIA's plan.
The FIA wants to remove the so-called MGU-H - the part of the hybrid system that recovers energy from the turbocharger - for 2021.
The FIA and F1 commercial rights holder Liberty Media believe this element, while powerful in increasing the fuel efficiency of the engines, has introduced unnecessary complexity and expense.
In addition, many question its relevance to the road car industry - which was used as one of the reasons to introduce it in 2014.
The hybrid system that recovers energy from the rear axle is to be retained for 2021 under the FIA's plan, and almost certainly made more powerful.
Mercedes, Ferrari, Renault and Honda - the four engine manufacturers in F1 - have told the FIA that they want to retain the MGU-H, arguing that removing it effectively means designing an entirely new engine.
The FIA and F1 argue that the current rules make it impossible to attract new manufacturers - part of their aims for a wholesale revamp of the sport in 2021.
One complicating factor in discussions is that the engine debate is wrapped up in a wider discussion about revenue distribution, cost control and changes to the cars to promote closer racing, plans for which were presented to the teams in some detail at the Bahrain Grand Prix on 6 April.
Mercedes F1 boss Toto Wolff described the presentation as a "good starting point for discussions".
Ferrari president Sergio Marchionne has reiterated his view that the company could quit F1 if the rules are made unattractive.
"If there are any proposals that distort F1, I think Ferrari will pull out," Marchionne said at a shareholders meeting this week.
"We are working with Liberty Media to find acceptable solutions.
"We had a proposal from Liberty 10 days ago. We expect to know the details and then we will make choices in the interest of Ferrari.
"We could look for alternative solutions. It's not a threat, but it does not mean we stop shopping."
Meanwhile, the two meetings on Tuesday - of the strategy group of leading teams, FIA and F1, and the F1 commission - agreed to make some detail changes to the rules for 2019.
- The fuel allowance for a race will increase to 110kg from 105kg to make it easier for cars to race flat out for longer
- Separating the weight of the car from the driver as a means of not penalising heavier drivers
- Drivers will wear biometric gloves to increase safety and facilitate medical rescue
No information was released on the subject of ongoing discussions to tweak the design of the front wings of the cars to make it easier to follow closely behind another car and therefore facilitate overtaking.