Fernando Alonso has lamented what he deems to be the unclear direction of Formula 1 and many failings of the current rules that are making him consider his future.
McLaren driver Alonso claims there are many aspects of modern-day F1 he currently dislikes, underlined by the V6 turbo hybrids and current range of Pirelli tyres.
Expressing his discontent, the double world champion told Autosprint: "These days F1 is in a time of highs and lows, for several things the series' direction isn't clear.
"I'm not at all happy for some things that are happening: we can never drive the cars to their real limit; we can never attack as much as we would like because the tyres don't allow you to.
"If you push too hard they overheat, and lose grip immediately. If you use the engine too much, you step over consumption parameters.
"To be quick in today's F1, you must not attack too much, that's the secret, but that's something against a driver's instincts.
"This is why current cars aren't as pleasing to drive compared to other periods, when the technical rule book was different. This situation doesn't make me too happy.
"I am not saying current cars are easier to drive, but they certainly are from a physical point of view or in finding the car's true limit.
"That's because before, when you were attacking a turn, the speed mid-turn was so high that you really had to trust your car, trust that it would handle it. With less grip, it's easier to find the grip's limit.
"Before, after 10 laps you had to have a two-hour massage, while now you can drive 150 laps and barely sweat by the end."
Alonso has already suggested the sweeping rule changes for 2017 need to make him enjoy driving F1 cars again if he is to continue in the championship.
If not, then with a year remaining on his current McLaren contract, Alonso reiterated he could be lured away from F1 by the Le Mans 24 Hours or the Indianapolis 500.
"Many things will change next year, let's hope the joy of driving will return to be a major factor," added Alonso.
"If I see F1 carries on going in a different direction compared to what I knew and loved in the recent past, at that point I could consider other alternatives and leave F1.
"Le Mans would be the option closest to my driving style, and to what I've always done.
"The Indy 500 is a fascinating, radical change because you must learn a completely different driving style and way of thinking.
"Nevertheless, I'd be open and ready to learn it because when you have been F1 world champion there are only two other races that are equivalent prestige-wise: the 24 Hours of Le Mans and the Indianapolis 500.
"But in any case it would be an idea, a plan that would be really long term in order to be turned to reality."
Translation by Michele Lostia