This year's F1 cars are wider, more physically demanding to drive and much faster than last year

Mercedes boss Toto Wolff says this year's intense battle with Ferrari has revived his love for Formula 1.

Mercedes dominated F1 from 2014-16 but Ferrari's Sebastian Vettel leads Lewis Hamilton by six points after five races of this season's championship.

Wolff said: "The last three years were extraordinary. But this season I have rediscovered why I love the sport.

"I love the intense competition. It means you won't be winning easily - you'll have a fierce fight."

Wolff added: "Because of that, the feeling is even greater when you manage to come out on top."

Hamilton won the last race in Spain to secure his second win of the season, the same number as Vettel.

The fight is equally tight in the constructors' championship, in which Mercedes' advantage is eight points.

Wolff said: "It's always good to come away from a race weekend with a points advantage, no matter how small. But the gap is just that: very small.

"We are in a massive fight with Ferrari. On one side, this is very exciting and challenging. But, on the other side, it is going to stretch us to our limits. You cannot base your current assessment on the balance of power on just Barcelona."

Who has won what in the 2017 season so far? Next stop: Monaco

Wolff said Mercedes had identified the cause of the engine failure suffered by Hamilton's team-mate Valtteri Bottas in Spain, blaming the turbocharger.

He said: "We haven't seen that defect before, which shows you that you need to be double diligent. This is a technical sport and if you stretch your limits, you'll encounter technical problems.

"We expect Monaco to be a completely different ball game to Barcelona.

"The circumstances, working environment and driving challenges are completely different to anywhere else - and you need to get everything exactly right if you want to perform to your maximum around those streets.

"Not every factor is under your control, either, so you need to turn fortune in your favour at the right time if you want everything to come together.

"Every weekend will push us to the limit; this is the new reality of F1 in 2017."

Hamilton said the challenge of Monaco would be different this year following the introduction of faster, more demanding cars, which are 20cm wider than they have been since 1998.

"We have new cars this weekend which are wider and faster, so that's going to be a massive challenge," Hamilton said.

"In trying to push the car as close as you can to the limit, it'll be a real test of your awareness of where the car is. I'm sure there will be some brushing of the barriers…

"It's a circuit which is all about mental strength. You need to be sharp and clear. Experience counts here too - that helps massively in setting the car up."