The spectacular rivalry F1 2018 promises

Mercedes boss Toto Wolff has often described his team's relationship with Formula 1 title rival Ferrari as that of 'frenemies': battling as hard as possible on track while enjoying cordial relations off it.

That's probably a fair assessment, for despite a few tetchy moments - such as last year's oil-burn controversy, or Sebastian Vettel driving into Lewis Hamilton in Baku - it has been rare for the Silver Arrows and the Prancing Horse to allow competitive circumstances to sour their rapport.

"For me the analogy is rugby," said Wolff last season. "During the race Ferrari are our enemies and I wouldn't take any prisoners, but we must be capable, once the race is over, to have a beer like rugby players and acknowledge we are all warriors and fierce competitors out there."

But if there are few reasons to expect that relationship to go into meltdown this year, you don't have to look much further back down the pack for a rivalry that has potential to explode in spectacular fashion - and it's a head-to-head that is guaranteed to deliver plenty of juicy headlines in the coming months.

In the blue corner is Red Bull, eager to make amends for a 2017 season in which it made a slow start, only fulfilling its ambition to get on competitive terms with Mercedes during the final stretch. In the orange corner, McLaren - full of optimism after securing a new engine partner, and bullish that it has all it takes to return to its very best.

Add to that the explosive combination of four brilliant, intense and highly rated drivers, all at different stages of their careers and all with something to prove.

But what makes the Red Bull and McLaren rivalry so tantalising is the inescapable factor of power-unit equality. The two teams have the same engine supplier, Renault, and that opens up the prospect of Machiavellian political manoeuvring as each bids to seize the upper hand in the customer pecking order.

McLaren claimed it blocked the return of shark fins for sponsorship visibility reasons, but word on the street suggests its real motive was to disturb Red Bull's aero development

It's a game changer for both in many respects - engine equivalency means neither will have anywhere to hide with regards to performance. Gone are the days when the blame for a lacklustre showing can simply be pinned on the lump of metal in the back of the car.

The finger-pointing game is one that both outfits have grown familiar with during the hybrid era, but Red Bull and McLaren are aware that such excuses will no longer be given much credence - and may explain why we witnessed the first hints of skirmishing last year.

When McLaren blocked the return of shark fins at the end of the season, it claimed it was doing so for sponsorship visibility reasons. Word on the street, though, suggests its real motivation was to disturb Red Bull's aero development, since rumours also abounded that Adrian Newey's team was planning something special for its rear wing.

When asked if marketing real estate was the sole motivation for his team vetoing shark fins, McLaren racing director Eric Boullier smiled before suggesting obliquely that there were perhaps some performance reasons.

"Maybe we have found a way to use the engine cover that works better," he said. "The cars are complicated today so it is difficult for Zak [Brown] to find big stickers. But we are not playing games. Everyone is developing their own car so if you ask for something which is against our interests, I will not go for it."

Politically, Red Bull and McLaren have previous. Remember which team had long-standing partnerships with Tag Heuer and Mobil 1 before Red Bull lured them away? The two outfits have come to blows over human resources as well. Back in 2014 McLaren poached Adrian Newey's number two, Peter Prodromou, and then threatened to go to court after failing to secure the services of Red Bull aerodynamicist Dan Fallows.

Prodromou himself is unequivocal about the competitive situation between the two teams. When asked if there was something personal in it for him about beating Red Bull with the same engine, Prodromou said last week: "Of course. Yeah, for sure!

"But not in a negative way. I've got fantastic feeling towards Red Bull. There is no animosity but it would be just fantastic to beat them. Obviously it is difficult to know exactly who contributes to that car nowadays, but I'm sure at least some of the people there are my ex-colleagues, and it would be great to compete and beat them."

Rather than worrying about being exposed against Red Bull in a straight head-to-head, there is a sense within McLaren of genuine excitement about no longer having anywhere to hide if the chassis is not up to it. It's had three years of being convinced its car is one of the best, but not having the means of actually proving it beyond some GPS interpretation.

"If we are nine tenths off Red Bull that wouldn't look good. We don't want to hide" Zak Brown

"It's been difficult for us for the past three years not having someone to measure yourself up against," added Prodromou. "So I think it's a very positive thing that we've got two first-class teams to measure ourselves against. That is a very strong motivating factor for everyone in the workforce."

But there is more to this rivalry than just championship places and bragging rights, for there is a bigger endgame at play here too. There remain doubts about how much longer the Red Bull-Renault partnership will last; they won four consecutive drivers' and constructors' titles together, but relations have soured during the hybrid era and Autosport understands that Renault is keen to terminate their arrangement as early as the end of this season.

While Renault's exact commitment remains unconfirmed, McLaren certainly senses an opportunity to emerge as the preferred partner...a scenario Red Bull will be eager to prevent.

As McLaren's executive director Zak Brown said: "When we made the decision to go with Renault it was long-term in nature. Obviously the relationship with Red Bull, we all see it and it has not been healthy, and it's good that we have a very healthy relationship with Renault.

"We think that when you look at the last time they [Renault] had big success with another team - Williams - they were absolutely dominant. We are set up for a long-term success together."

There can really only be one winner from this battle between McLaren and Red Bull, since it is highly unlikely that we will end 2018 unsure about which team has done the better job. Looking at the bigger picture, there is an awful lot at stake for both outfits, which is why things are going to be so intense between them.

"If we are nine tenths off Red Bull that wouldn't look good, I agree. We don't want to hide," said Brown. "This is show time.

"I think the beautiful thing about motor racing is that hundreds of million of people get to see how you do. That is part of the adrenaline, and we look forward to that."