I think refuelling needs to be allowed again, as the drivers have to drive within themselves because the tyres are the new limiting factor, and the fastest way is to crawl around and stop less. When we had refuelling, you could have a tyre change for free whenever you needed fuel and were flat out much more often. However back then everyone just waited until the pitstops to jump the car in front.
The FIA have the devils own job, but I think with ERS and DRS, a return to refuelling might just work.
The FIA have the devils own job, but I think with ERS and DRS, a return to refuelling might just work.