Weight affect acceleration

[mod507]

How much weight does it take to affect your 0 to 60 times? I've heard like 100 pounds slows it down .1 second. Does anyone know better?

[Kronos1965]

I'm sure someone around here will do a power to weight ratio for you but so many other things affect 0 to 60 times...

I wouldn't haul a bear in the bed but if you're that concerned...remove the tailgate, limit how much gas is in the tank, pull the other seats out, and don't eat that meal before you hit the strip!

I assume you're not asking about gear ratios, humidity, tire pressure/tire temperature/tire size, all the performance mods out there...

[mod507]

Yeah I was just wondering because my friends like to race me and I always have my work tools in there and I wanted to know how much they slow me down.

[SpeedFreak]

It all depends on how much weight are in your tools. My father a mechanic would often have over 300lbs of tools in his truck and this can make a difference in a win or a loss with 2 trucks of near equal performance.

Gasoline weighs around 6.8 lbs per gallon depending on temperature so you can see that a full tank can add up quite a bit.

[mod507]

wow thanks, I didn't think of gas weighing that much and I do have about 300 pounds of tools.

[Titano24's]

The rule of thumb is that for every 100lbs you will gain or lose around 1/10th in the quater mile.

[Armada]

That one tenth per one hundred pounds is a good general rule, but it seems to work best for cars that weigh between 3000 and 4000 lbs. As weight goes up, or down from that range, it tends to become less reliable.

For instance, the best indicator of acceleration is pounds per horsepower, also referred as power to weight ratio. That's why a motorcycle can stomp our trucks with less than 1/3 the power.

If you have a 3000 pound car with 200 horses (at the flywheel), that is 15 pounds per horse. That car is usually going to turn about a 14.5 to 15 second quarter. If you go up to 6000 lbs in weight it will take twice as much power at the flywheel (about 400 horses) to do the same thing.

This assumes that you have the same traction and same aerodynamics, and that drive line losses are the same.

Our trucks are at about 5,000 to 5,500 lbs. My Armada is 5,600 empty. With me and just a little fuel and junk on board, I'm 5900 to 6000 lbs.

That means that for a 5000 to 5500 lb. truck, it would take about 340 flywheel horsepower to produce the same performance. That's what our trucks seem to have.

If you add 100 lbs to the 3000 lbs car, you change the power to weight ratio by about 3%. To change the power to weight ratio in a 6000 lb. vehicle by the same percentage requires 200 lbs.

Thus, an increase of 100 lbs weight in the 3000 lb. car or even up to about 4000 lbs., probably would cost you about tenth in the quarter. But move up to 5000 to 6000 lbs, and it would take more like 150 to 200 lbs to have the same effect. That would be maybe a half to 3/4 of a tenth - .05 to .075 seconds loss per hundred.

You can add more weight to a heavy vehicle and not affect its acceleration as much as adding the same amount to a lighter one. Put an extra 100 lbs on a motorcycle and watch performance drop off noticably. Add the same hundred pounds to a 2 1/2 ton capacity diesel work truck and see if it changes acceleration much at all.

The engineers here can further refine this concept and explain it far better, but this is the general idea.

Still, for most vehicles on the strip, the one tenth per hundred rule works out pretty well.