I find myself thinking about car lifetime weight MPG penalty Topic is solved

[matthew1]

For instance: Bob adds a 400-lb pushbar bumper to his truck. They might weigh even more than this. That's a lifetime MPG penalty, and possibly other downsides I'm going to ignore for the sake of conversation.

What's a good way to calculate lifetime cost per mile of additional weight for any given vehicle?

I see people with 5500-lb pickups and they camp once a summer. We're so spoiled we can and do waste money on stuff like this. It boggles my mind.

I see new Jeeps with custom front/rear metal bumpers that must weigh a whole lot more than stock, and external frames for carrying all manner of junk like those plank things to help a wheel out of sand, jerry cans, shovels, jacks, etc.

[BlackBart]

Good question! How much are we hauling around for no reason? We have Expedition Dads showing up at the school in giant commando "rigs" in order to pick up their tiny daughter in pink ribbons.

We could do like Eddy Merckx and start drilling holes!

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Team car!!

eddy_merckx_molteni-Volvo.jpg (62.13 KiB) Viewed 399 times

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[matthew1]

I think a crude method for calculating lifetime MPG penalty would be to set the EPA blended MPG rating as a baseline, then divide by factory weight and go from there for additional weight.

I think 90% of people don't truly understand MPG, only how much a fill up costs, which of course is subject entirely to the size of the car's gas tank.

“Cars are great for going long distances, but it makes no sense at all for people in cities to use a 4,000-lb. piece of metal to haul their 150-lb. ass around town.” -- Dean Kamen

I admit I thought the Segway (Kamen's invention) was going to change cities.



Super cool and interesting:

[BlackBart]

Interesting idea - you could calc a mpg per pound to compare. Sort of like passenger miles per gallon for a bus full of people.

[matthew1]

exactly

[matthew1]

But it's still crude, because it would distort wildly as you took the weight down to near 0.

[matthew1]

Abscate, we need your help here. Paging Abscate. Please come to a white telephone.

[volvolugnut]

A quick google check found this link:
https://www.quora.com/How-much-weight-d ... pg?share=1

Short answer: 100 pounds added will cut mileage 1%.

If you added weight AND big tires, the added rolling resistance would drop the mileage even more.

Most people do not think about their mileage, they only think in terms of their ego and maybe how much they pay for fuel. If paid by credit card, they may not even realize their fuel cost.

volvolugnut

[abscate]

I was going to swag it at 1% per hundred kg

[BlackBart]

Very interesting. This with aero drag would tell you a lot of about efficiency.