The team submitted eight technical changes to the FIA for the Silverstone weekend.
These are led by a reworked floor with a raised edge, a tweaked diffuser to reduce how much the wake from the rear tyres distorts the airflow and wider engine cover bodywork.
An extra winglet has been added to the rear suspension wishbone and a revised rear and beam wing introduced to reduce drag and improve straight-line performance.
But after Tsunoda clocked 16th in FP1 before running to 18th, the Japanese driver says the updates have not provided an immediate boost.
Asked by Motorsport.com to assess his first laps aboard the revised AT04, Tsunoda said: “So far, we can't see the results that we are improving massively.
He added that a couple of improvements were noticeable from the cockpit but, in some areas where the team had expected to take a step forward, the gains had not arrived.
“So far, it’s not looking good,” he said. “The result is no good so far.
“We feel definitely a couple of gains in some places but some places we didn’t improve that we expected. So, we have to look through it deeply.”
Pirelli introduced its new tyre construction for the British GP, but Tsunoda said the team’s struggles were independent of the changed rubber. The early impression of the upgrades has left Tsunoda to target Q2 rather than the top 10 in qualifying.
However, AlphaTauri chief race engineer Jonathan Eddolls reckons the Friday woes were more a result of a suboptimal car set-up rather than being attributed to the new components.
He explained: “Analysis showed that the update is actually working well.
“We made further changes to the car in FP2, but it’s fair to say we didn't hit the sweet spot with either car in terms of balance on the soft tyre short runs, lacking front end, which is a lap time killer here.
“High track temperatures exacerbated the front tyre overheating which resulted in a lack of front grip, so we think there is a step of lap time to come with better balance.”
Nyck de Vries ran to 19th in FP2 and suffered a late front-right puncture.
