Since 1995, McLaren has been using Mercedes-Benz engines, but after two difficult seasons in F1 their new deal with the Japanese car manufacturer renews one of the most successful partnerships in motorsport's elite class.
"The first few races I predict will be problematic, as we wrestle with what we hope are performance advantages, and inevitably performance advantages sometimes carry unreliability with them," Dennis told CNN's Amanda Davies in an exclusive interview.
"Once we've got that in control, I think our competitiveness will be quickly established, and I feel when coupled to two world champions, and the talents of Fernando Alonso and Jenson Button, I think that the outcome I hope will be inevitable: that we'll return to our winning ways," he added.
During those halcyon days of domination, McLaren and Honda won 44 out of the 80 grand prix they raced as Ayrton Senna and Alain Prost secured a clean sweep of world titles between 1988 and 1991.
It was the type of stranglehold Mercedes had over F1 last season when world champion Lewis Hamilton and teammate Nico Rosberg at times appeared to be only racing against one another.
Last year, Mercedes won all but three of the calendar's races, finishing with at least one car on the podium at every single race.
While admitting to a "degree of guesstimate," Dennis believes McLaren, which signed a multi-year global partnership with CNN at the start of 2015,
are not too far behind Mercedes, the team predicted to once again dominate the new season that gets underway with the Australian Grand Prix on March 15.
"It's unlikely that anybody has surpassed the efforts of Mercedes-Benz. And in sheer horsepower terms we don't really fear the Mercedes-Benz engine," added the McLaren boss.
For motorsport fans the 1988 McLaren-Honda MP/4 car is one of F1's most historic pieces of machinery after it won all but one of the 16 races that season.
Speaking to CNN ahead of the launch of the team's new car Thursday, Dennis conceded it was unlikely that the new incarnation of the partnership would be able to replicate that level of success, preferring to emphasize that Alonso and Button were key to McLaren's hopes of success.
"The tendency of the regulations at the moment is to put more control back to the driver," said the McLaren CEO as he compared F1's pilots to "automotive musicians."
Dennis added: "He has to be able to play with these devices and optimize the performance of the car, sometimes even during the lap.
"So driver competence is going to play a very significant role in the future of grand prix racing until there's another regulation change."
But managing two world champions is never easy — as McLaren and Dennis discovered when Alonso left after just one season (2007) with the team due to tensions between the Spaniard and then rookie teammate Hamilton.
Before Alonso returned to McLaren for a second spell, Dennis conceded that "a great amount of time" was spent talking between the two of them about what had gone on before.
"I have to say it's more about the future than about the past. That as a topic was really about one third of the discussion and it was quickly dealt with. I mean we're older people ..."
While Alonso's seat at McLaren was sorted out "five or six races before the end of the season," Button was left to sweat over his F1 future.
Eventually he signed a new deal to extend his four-year stay with the team in December, with his services retained above Kevin Magnussen, who stayed on as a test and reserve driver.
"These drivers had contracts through to the end of 2014 so there's no contractual necessity and I was absolutely open to both drivers about what the process was," said Dennis.
"So I can understand the fuss but the fact is we're a business. We're a sport in a business, there's a right time to take the decision, and the right time to take the decision was the time it was taken. If it had been appropriate to take it sooner we would have done."