Renault managing director Cyril Abiteboul says the French manufacturer has finally received some positive feedback from Red Bull's Formula 1 advisor Helmut Marko, a long-time critic.
Marko was one of the most outspoken characters in last season's acrimonious breakdown in the once-successful Red Bull/Renault partnership.
With no other manufacturer willing to supply an engine, Red Bull was forced to do an about turn on its split from Renault, albeit running a system now badged as TAG Heuer.
Following two relatively successful pre-season tests, and with Renault confident it has found a half-second improvement in its power unit, Abiteboul said: "The engine is much more reliable, the car is also reliable, Red Bull is happy.
"I've had very positive comments from Helmut, so life is beautiful. But I take nothing for granted."
Red Bull founder Dietrich Mateschitz has also expressed satisfaction with Renault.
"Though the power train is basically the same as last year, I got the impression that Renault is pushing hard with new people in responsible roles," he said.
"They show passion, a very professional attitude and a desire for success."
With Renault focused on its works team, Abiteboul claims the relationship between the manufacturer and Red Bull is now perfectly civil.
"It's positive. It's never really been that negative," added Abiteboul.
"I always have had some respect for Red Bull's capacity to chase performance at any financial, marketing and political cost.
"While I have respect I am also looking after the programme of a large carmaker which cannot accept its brand being criticised.
"That was the watershed, when there was some criticism. They can say I'm an idiot, that we've done a bad job, but they cannot say anything negative about the brand.
"But that's history, that's in the past. Let's focus on the future and good things, and the relationship is good."
Abiteboul claims the split, as such, has allowed both parties to concentrate on what each is good at without meddling in the other's business.
"When we agreed to continue the collaboration with Red Bull, frankly, as far as I'm concerned, I believed it to be a good thing for Renault, and maybe it will turn out to be a good thing for Red Bull," assessed Abiteboul.
"One of the fundamental, key principles on which we agreed is that 'You do the chassis, and you do it very well. Let us do the engine'.
"We've been doing that fairly well over the past few decades. We've had a blip, but that doesn't mean that suddenly you should get involved in that. We tried that. We failed.
"Frankly, they were responsible for designing and producing a number of parts last season that turned out to be a complete headache.
"It was a mistake to let that happen, and also my mistake to let that happen.
"There was an attempt to build some bridges with Red Bull. It was not delivered, so now everyone is back doing their own thing."
Additional reporting by Gerhard Kuntschik