A car may shake at 45 to 55 mph due to several potential issues, such as unbalanced tires, misaligned wheels, or worn suspension components. Imbalances in the tires can cause vibrations that become noticeable at specific speeds. Additionally, problems with the drivetrain or brake components could also contribute to the shaking. It's important to have the vehicle inspected to identify and resolve the underlying cause.
its not spossed too...you may need to balance your tires
45 mph is the same as 45 mph. How can one of the two be faster?
I should have said that the car seems to sputter at those speeds rather than shake so I don't think it's a tire problem which most people tend to think of.
a = (vf - v0)/Δt 10 mph/s = (45 mph - 20 mph)/Δt Δt = 2.5 s
It is possible that the shaking in a Pontiac Montana at 45 MPH is the result of failing bearings or tie rod ends.
90seconds
neither
problem with your transmission in 5th gear
Tires and/or wheels out of balance?
Wheels are probably out of balance or you may have a bad tire.
No.
24 x 60/45 ie 32 min.