On any upgrade, gravity will: Question On any upgrade, gravity will: Answers Speed your vehicle up. Slow your vehicle down. Not impact your speed. Explanation A vehicle will be slowed down by gravity on any uphill grade. You may need to switch to a lower gear to climb a steep grade. This questions appears in the following tests: Alabama Double Hawaii Passenger Idaho Class A Knowledge Test Idaho Tank Missouri Class B Knowledge Test Missouri Tank Nebraska Class A Knowledge Test New Hampshire Class B Knowledge Test Washington Class A Knowledge Test Wisconsin Class B Knowledge Test