Does Speed Add Weight?

s.e.charles

Well-known member
there must be some engineering - physics calculation that applies. for example: i'm driving a 6,000# vehicle with an additional 1,000# payload = total weight (static) of 7,000#. this is distributed over the entire vehicle although most likely not an even distribution. anyway, now we're getting going to say 50 mph. leave out altitude, grade change, or wind force other than whatever the vehicle is "generating" if that's the correct term.

could the conclusion be the vehicle now "weighs" more than static weight? less?

these are things which I ponder . . . .

BUT - not for naught. after reading some thread responses regarding mounting bolt hardware, would it be completely illogical to have an "engineering" stickie without opinions or responses, but simply "by the numbers" facts? I would help folks trying to do a good job, to do a good job.
 

Joe917

Explorer
Total weight does not change. Acceleration (in any direction) causes weight transfer.
Aerodynamics also have an effect, probably minimal in an expedition rig. The rear wing on my old Porsche developed 400 lbs of downforce at 75mph.
 

s.e.charles

Well-known member
… weight does not change. … rear wing on my old Porsche developed 400 lbs of downforce at 75mph.

so the additional 400# must be accommodated in the suspension engineering; correct? would that be any different than adding 400# of feathers/ lead to the vehicle? does weight engineering at the design/ factory level consider this?
 
You better hope it adds weight. If it doesn't add weight then you will be flying like a plane. A plane generates lift the opposite of what a vehicle does. Yes modern day factory engineering takes this into consideration. If it didn't the suspension could be too soft.
 
When the factory list Gross Vehicle Weight that is the maximum weight of the vehicle including payload. Payload being cargo and passengers. They do take into consideration speed when calculating this. You wonder at what speed do they use? Speed would be based on what tire the factory uses. There maybe other factors that the factory uses to determine what base speed is.
 

Joe917

Explorer
The car is designed for the weight, Weight transfer to the front wheels under braking is huge, braking hard enough into a corner can lift the inside rear wheel off the ground.
All vehicles are engineered to take weight transfer into account.
Aerodynamic effect, wings, airdams etc, will add weight, but this downforce is negligible in a heavy brick shaped truck or a Ford Bronco!
 
Bronco equals giant shoebox.

Speed generates downforce which appears as additional weight on the chassis, suspension, and drivetrain including tires.
 

Joe917

Explorer
Speed does not generate downforce.
Air moving over an aerodynamic surface creates downforce (or lift) An aerodynamic surface can be anything that redirects airflow, from a giant wing to carefully sculpted wing mirrors. Downforce also creates drag, drag raises fuel consumption. Automotive designers avoid drag as much as possible. Only performance/race cars get more downforce with speed.
 

Buliwyf

Viking with a Hammer
Generally, most cars generate lift at greater speeds.

Flat (even if bumpy) bottom, round smooth tops. Just like a wing.
 

Joe917

Explorer
The faster you go the more you weigh, but until you get close to the speed of light this is not a measurable effect.
 

s.e.charles

Well-known member
Its claimed an objects mass increases as its speed increases.
When driving a small ExPo jeep and about to crash, its best to accelerate just before crash to simulate driving much heavier vehicle.
As an aside.
Faster one goes, more fuel consumes. Vehicle weighs less and less...

this reminds me of the "elevator theory". if the cable snaps when you're on an elevator, just before the car hits the bottom of the shaft, jump in the air as high as possible. you will not be hurt; Moe, Larry, & Curly proved it.
 
The faster you go the more you weigh, but until you get close to the speed of light this is not a measurable effect.
I thought it was 88MPH

this reminds me of the "elevator theory". if the cable snaps when you're on an elevator, just before the car hits the bottom of the shaft, jump in the air as high as possible. you will not be hurt; Moe, Larry, & Curly proved it.
Just like if you are in an airplane and you jump up you will go flying into the back wall.
 

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