Interesting article by motor sport magazin:
http://www.motorsport-magazin.com/f...rsachenforschung-ricciardo-wieder-vor-vettel/
Helmut Marko pretty much saying what you heard dhel with regards to engine mappings changing, now I know this is Helmut talking but he isn't afraid to highlight flaws in Vettel during the 2012 season and is mostly honest with his reviews. It seems the mappings for Daniel have been more consistent compared with Vettel's which haven't been to what he desired.
Not quite as Red Bull motorsport advisor Dr. Helmut Marko said: "There are reasons for Sebastian has more problems with the engine mapping Daniel is lucky that his mapping is constant - we need to put right on Vettel's car too!.."
Different Mappings
A brief digression into the technology of Formula 1: A motor does not work just like that. He needs - simply put - meticulous engine control unit instructions. For example, how much fuel to be injected or when each of the six spark plugs to ignite the spark exactly. There are different mappings, so basic settings.
Pilots can choose from the cockpit between different mappings. For example, there are settings for safety car periods when very little power is required and fuel can be saved for qualifying laps, when the gasoline consumption almost does not matter and so on. These mappings are apparently not identical with Ricciardo and Vettel.
Since beginning of the season Red Bull is working on different software settings. To compensate for the power deficit of Renault Power Unit, the world champion team attempted extract with aggressive programming more power. Apparently you go at Vettel here more risk than with Ricciardo. What in the optimum case brings more maximum power, even dangers.
Rain makes deficits significantly
Drivability, that is, the way how the motor delivers its output, suffers from the aggressive mapping. "When it rains, it is particularly difficult when the engine response is not equal to" Marko continues. Three out of four qualifying sessions took place in 2014 in the rain.
The performance of Ricciardo but he does not want to belittle: "It was a great round of Daniel, who has struck at the last moment and has got the maximum out of the tires." At the same time Vettel made on his final lap a small error, which explains the large distance.
All these factors make it difficult to draw an honest comparison. Ricciardo here has the disadvantage of Nobody: Everyone looks cramped for explanations for something but can not be: Vettel beat. In the end, Marko must confess: "Seb and Dani are more or less the same level." Nevertheless, Red Bull has to put the question why you received this risk when Vettel. The rain finally came not out of the blue.
And even in race trim seems Ricciardo's setup to work better what the last race and the long run analysis in motorsport Magazin.com have shown.
Makes sense to be honest, traction was always his strongest suit and if you start controlling that away from the way he likes it for more engine power to catch up Mercedes what do you expect.
EDIT: It wouldn't also be far fetched that testing was the reason for this as well since Daniel was able to do a partial race runs during the early stages of the car at Jerez where as Vettel was always getting the bad luck with reliability and never got a decent race stint to gather info on etc.