Re: Top speed and vehicle weight

[Alexei M Voloshin <Alexei.M.Voloshin-1@tc.umn.edu>]

On an asphalt road  all of these effects can be neglected compared to 
aero drag. 

Alex  
 
> 	I must confess, I've ignored the top speed thread, but your 
> comment here is interesting.   Top speed does depend on weight, although 
> not as much as any acceleration-based performance parameter.   Extra 
> weight causes greater wheel bearing resistance, greater tire rolling 
> resistance, and greater suspension resistance.   The first two are pretty 
> obvious, but the third point may be a little more obscure.   When a car 
> going down the road hits a bump, the suspension takes up the bump, and 
> hopefully, the car chassis should stay pretty much steady.   
> Obviously the greater the bumps, the greater the amount that the car will 
> be jolted.   Think of the car travelling across a plowed field.   If the 
> bumps are very high, then the engine must pull the car up the bumps, 
> which requires more energy.    If the road was perfectly smooth, then I 
> would expect weight to have a very small influence on top speed, but 
> since all of our roads are not perfect, it takes more power to traverse a 
> road with a heavy car than with a light car.   Conversely, a lighter car 
> can achieve a higher top speed than a heavy car, all other factors being 
> equal.
> 
> Later,
> Graydon D. Stuckey 
> '86 5KCSTQ, getting more toys every day...
> 
>