This will be the final Mercedes upgrade to their 2022 Formula 1 car, which has proved to be a difficult car to handle with its zero-pod design including bouncing tendencies (porpoising).
Shovlin gave more information on the W13 upgrades, and said: "It's our final step of aero development and that will hopefully give us a bit more performance.
"But importantly with every step, we are learning more and more and that learning we can carry into next year," Shovlin said.
"So that's part of it, also there is a few bits where we have taken some weight out of components that will hopefully get the car closer to the weight limit."
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The engineer admitted that it was difficult to predict what the outcome would be of the upgrade and whether or not it would have them challenging at the front of the grid.
"It's very difficult for us to predict where we are going to be," Shovlin said. "In Singapore Lewis was awfully close to pole position, yet in Suzuka both cars had a big gap to the front.
"Now, our race pace has been reasonably strong, so, if we can make a step hopefully, we can get into the fight with the Ferraris and the Red Bulls but qualifying for us is the really difficult one to predict at the moment.
"But as I said a lot of it is about learning and we are certainly going to give it our best shot in the final four races," the Briton added.
The Circuit of the Americas (COTA) in Austin is known for its uneven bumpy surface, and Shovlin thinks the circuit will be a challenge for Mercedes as they have struggled there in the past.
"It's a tricky circuit and it was a tricky circuit for us last year," Shovlin admitted. "It was very bumpy, there was a lot of overheating as well from the tyres, and we weren't performing as well as Red Bull were on the softer tyres.
"They have done some resurfacing so hopefully those issues with the bumps are a bit less. But what's very hard this year is to really know where you are going to be on the circuit before you've gone there.
"We will not really be going to make any predictions about where we are going to perform, we just need to go there on Friday, see what kind of issues we have, and then see whether we can solve those with set-up," he concluded.