After a difficult start to the season, the car showed signs of progress in Australia, helped by an issue for Sergio Perez in qualifying, which saw George Russell take second on the grid and Lewis Hamilton finished runner-up in the race.
But speaking on the F1 Nation podcast Allison, who has returned to the technical director role after a job swap with Mike Elliott, said the car’s performance is still far below what the team expects.
"It's reliable, that's a definite strength," he said when asked about the characteristics of the W14.
"It's got very good pair of punters peddling it around. It's better than most of the grid out there. But until it's the quickest one, it will always feel like a weak car to all of us.
"It's adequately kind to its tyres, but not as good as some of the cars that we've made in the past. It's got more downforce than most of the cars on the grid, but not sufficient. Its handling characteristics leave a little to be desired, and need to be worked on for sure.
"But none of this stuff is revelatory. We've been talking about it most weekends. And it's part of what this team needs to address to get winning material back in our hands."
Allison didn’t want to be drawn on which circuits might favour the W14, but suggested instead that the parameters will shift as the year goes on and updates are introduced.
"It’s quite early in the season to be diagnosing what your car is great at or what it isn't great at, because the car's not a fixed thing," he said. "It's a platform that develops all the way through the year.
"If I had to pluck something out of the air now, I'd say that we tend to be a little stronger at the front-limited circuits, rather than the ones that are heavily rear limited.
"So a Bahrain-type track is all about how well a car will look after its rear tyres. Melbourne was a bit more on the front-limited end of the spectrum. Other front-limited tracks, Barcelona's one, Silverstone another.
"But honestly, it feels too early to be predicting that because these are young rules, this is a young car, and there's plenty to give to it."
Allison confirmed the team will have a new package in Azerbaijan and will continue to bring updates as the season unfolds.
"The flow of new parts has already happened," he said. "You pretty much have a different car every weekend you take it racing. Sometimes it's a few more parts, sometimes a few fewer. But we've had new things for each of the races.
"Baku won't be any exception, and I would hope that we can keep that coming. You're constrained by cost caps and stuff eventually.
"But we're at a stage in the season where there's still plenty of firepower there to keep putting lap time on the car weekend by weekend."
Asked which teams Mercedes regarded as its current opposition, Allison stressed the focus was on a bigger picture of pursuing an overall performance gain.
"We try not to think really in those terms," he said. "Just concentrating on what are the areas of opportunity on the car?
"How quickly can we fill those opportunities with hardware or different approaches, with the expectation that that will improve our chances at any given weekend?
"The sooner we can do that and on the steepest slope possible, the better our chances will be in any given weekend and up against any given team and in the championship.
"But we're completely realistic about the significant performance of the Red Bull and particularly Max [Verstappen]. They're going to be extremely worthy opposition to hunt down and then in due course overtake."
