How much does weight have to do with fuel economy???

[Compaq888]

Originally Posted by SVOboy

I think weight is very noticable at the track.

In talking to disco about this at length, I learned that weight's importance increases proportionally to the rate of acceleration.

So, if you floor it to redline everywhere, you might notice the difference, if you drive carefully, doubt it, though it will be there.

Someone should test the weight/CODFISH distance relationship.

codfish???

[thisisntjared]

there are soooo many other factors at the track....

[diamondlarry]

I would never say that weight doesn't matter at all. I like how SVOboy said it:

SVOboy I think weight is very noticable at the track.

In talking to disco about this at length, I learned that weight's importance increases proportionally to the rate of acceleration.

So, if you floor it to redline everywhere, you might notice the difference, if you drive carefully, doubt it, though it will be there.

Someone should test the weight/CODFISH distance relationship.

In FE however I don't think it is as significant as improving combustion efficiency.

[MetroMPG]

Originally Posted by Compaq888

Darin removed most of his interior and it looks like his mileage went up. Can anybody do some scangauge testing on this or present scangauge data???

I removed weight for 2 separate runs only, then I put most of it back in again.

I did remove a significant amount: reduced the car's weight by 6.1% - or 112 lbs: passenger seat, heavy rubber (winter) floor mats, cargo shelf, rear seat, spare tire & jack, car tool kit & spares (jumper cables, emergency light, oil, washer fluid etc.)

At the time, I said:

I think the added lightness was perceptible. i could shift sooner and not lug. Of course, that could also be the 10-15F warmer temps, the placebo effect, higher tire pressure (from warmer ambient), etc., etc. the car was definitely noisier inside - can't blame that on anything else.

Having made that disclaimer, 2 of the 3 highest segments I've seen to date were with that weight removed.

[philmcneal]

codfish is the new term to describe non hybrid cars who wish to coast with the engine off.

I think 40-50 pounds will make a difference in the low rpms, where torque is lacking.

[krousdb]

100 lbs is the difference between climbing a certain hill on my route in 5th or 4th gear. Other than that, I have no data on how it effects FE. For sure, each time you use your brakes you throw away some momentum, which depends on weight. Lower weight means less frictional losses during braking.

[Compaq888]

Originally Posted by krousdb

100 lbs is the difference between climbing a certain hill on my route in 5th or 4th gear. Other than that, I have no data on how it effects FE. For sure, each time you use your brakes you throw away some momentum, which depends on weight. Lower weight means less frictional losses during braking.

so it should help.

[MetroMPG]

Adding a 1/4 lb worth of ScanGauge would help more.

OH! I just had to get that in there. Old wounds. Pick. pick.

[Compaq888]

Originally Posted by MetroMPG

Adding a 1/4 lb worth of ScanGauge would help more.

OH! I just had to get that in there. Old wounds. Pick. pick.

I'd love to get a scangauge, first I have to pay off my debt thanks to the accident and my rack&pinion blowing a seal.

[Sludgy]

There is a fuel economy difference between removing sprung weight and unsprung weight:

If you remove sprung weight, like seats, spare tires and the jack, the car will ride higher, making it less aerodynamic.

If you remove unsprung weight like tires and wheels, you do not change the ride height, and this change doesn't impact the aerodynamics.

In addition, reducing the tire and wheel weight also reduces the angular momentum needed to accelerate them to speed.