The Australian completed 70 laps on the first day of running for the new Ferrari-engined STR8 at Jerez, setting the fifth fastest time of the day, and was cautiously optimistic about its handling characteristics.
After being faced with limited set-up options last year, Ricciardo has warned that the team's priority is now to ensure that it understands how changes affect the car.
"We have definitely got a bigger window to work with," said Ricciardo when asked by AUTOSPORT about whether the set-up window is wider.
"Whether it's going to be easier or more confusing, we'll soon find out, but we definitely have got more options this year and that will help us.
"But we've got to understand them first because the car is more complex and hopefully we can use this test and Barcelona to understand it all, otherwise it will be a bit of a gamble going for it on the race weekend.
"Today, we got through a bit of the programme of exploring the measure of the car but we have still got a long way to go."
Ricciardo admitted that his initial feeling about the car was positive after a constructive first day of testing.
But he was wary of getting drawn into believing that it was a major stride forward in case things get more difficult.
"The first impressions were positive," he said.
"Trying to recall this position last year, I do believe we've made progress, but it's always the case.
"Maybe this year I won't get too excited because it leaves more for disappointment, but the initial impression was good.
"There's still a lot of work to do and with this circuit you have to take it with a pinch of salt because the surface is very abrasive and the conditions are unique.
"Until we get to Barcelona, the picture won't be so clear but for the first day, we've got to be happy."