Forza Motorsport
57 Achievements
1000
120-150h
PC
Xbox Series
Strategist
Changed your Fuel and Tire setup for the first time
10
38.46%
How to unlock the Strategist achievement in Forza Motorsport - Definitive Guide
soul popped
TrueAchievements
TrueAchievements
This is not done in Upgrade & Tune, but rather in the screen immediately preceding a race.
You can unlock this in career mode (and likely other modes as well). After selecting your event (i.e. the Practical Performance within the Builders Cup) and your race, continue through Upgrade & Tune.
If you have practice laps enabled, go down to Car, then Fuel & Tire. Make any modifications (such as changing the Fuel load from 100% to 99%), then click
/ Done. Once you return to the menu, your achievement will pop. (It took my game 10-15 seconds to register it.)
This can also be done before a race, not a practice lap, on the screen that cycles through all the drivers. Instead of hitting
for Driver List or to Go Race, you can click 
to modify your Fuel & Tire.
You can unlock this in career mode (and likely other modes as well). After selecting your event (i.e. the Practical Performance within the Builders Cup) and your race, continue through Upgrade & Tune.
If you have practice laps enabled, go down to Car, then Fuel & Tire. Make any modifications (such as changing the Fuel load from 100% to 99%), then click
/ Done. Once you return to the menu, your achievement will pop. (It took my game 10-15 seconds to register it.)This can also be done before a race, not a practice lap, on the screen that cycles through all the drivers. Instead of hitting
for Driver List or to Go Race, you can click to modify your Fuel & Tire.
SSmasterONE
TrueAchievements
TrueAchievements
Right before a race starts, change your Fuel and Tire setup by making any changes and once you hit apply, the cheevo is yours.