weight loss
 

Ive seen people talk all about modifying their engines, areo mods and what not. but has anyone thought about doing serious weight reductions?
things like replacing your hood, fenders, boot and doors with fibreglass/kevlar/carbon. and replacing some, if not all windows with lexan?

Hi achang1--

I don't know about that but what about losing weight personally? As in hitting a treadmill? I wonder how much gas could be saved if we all lost weight. :D:p

Weight lose is certainly helpful. Lighter cars benefit more because you don't need to lose as much weight for gains. But when you start talking about changing the hood and windows that is going to start getting expensive. Remember also that most people on this site do tend to P&G some and a lower weight does affect the glide part.

I drag race a 84 Plymouth Horizon that now weighs 1810 lbs with 3 gallons of fuel so I definately did the wt loss thing on it,,,,and now my 96 Geo Metro has seen some of the same wt loss mods, but will not go as far as the Horizon. I drive the car to the track so I kept the heater and a single wiper. It has no dash and no interior except one seat and all the door panels. The rear doors are gutted and lexan is in use on both back doors and hatch. I was only able to get rid of a quick 70 lbs in the Geo so it is down to 1730. I will not put on lexan since it is my dailey driver and will sit out in the winter....it's rough to use an ice scrapper on lexan! Since my 2 year old rides in the back I have not removed inside panels or braces. My future plans are to remove the rear seat and place a single front seat in its place.

PERSONAL WEIGHT!!! I retired from the post office July of last year and went fron 264 down to 229 by sending my wife to work while I am a stay at home dad! I am too tired for a treadmill, but we did decide to get one in Oct.

weight reduction
 

The tough thing about weight reduction,is that the low-hanging fruit has already been plucked.By the 1980s,carmakers had already trimmed 1200-lbs off the weight of the average car.--------------- With present safety standards,the "mass" of your unibody and bolt-on structures is actually part of progressive deformation and destruction designed for it's crumpling,so as to allow its destruction,while preserving your ability to walk away from a crash and drive another day.------------------- And the gauge of today's steel is so thin (safety and weight reduction),it makes remarkable weight savings,even with composites,hard to pull off.--------------------------- Remember,you've got to lose 10% weight to see a 3.8% increase in mpg.That's 200-lbs off my CRX,and that's hard to do,even with carbon-fiber epoxy.---------------------------- I pretty much gutted the CRX for Bonneville,and the noise/vibration/harshness was so marked,when I got back home,I put everything back in so so I could stand to drive it.I've even added a couple extra pounds of sound-deadener.Early Hondas are really "harsh"!------------------- Adding 1,300-lbs and a second axle to the CRX only cost me 2-mpg on the highway.Once rolling,weight isn't that big a deal.In the city its the biggest deal and aero is meaningless.My solution was,get out of the city.

There have been many studies on this, and it's quite a lot, but don't tell certain hypermilers that or they might be sad, :p

Here's how I took a bit of weight out of my 240sx. I was prepping it for a racing class that required the interior and most of the road going equipment, so there's another EASY 100lbs in the car if you're willing to give up things like AC, passenger seats, sound deadening and so on.

Weight with 3/4 tank of gas and as delivered from the factory - 2828lbs
Est. Current Weight - 2608.5
Weight Savings - 219.5

adjustable coilover suspension - 16lb savings over stock suspension setup
remove spare tire - 31lbs
jack/tools - 6lbs
power antenna - 2 lbs
floor mats - 8 lbs
stainless steel header - 15 lbs (savings over cast steel manifolds
S.S. exhaust - 30 lbs (savings over factory thick wall exhaust/resonator/large muffler)
secondary horn - 1.5 lbs
cooling fan/ lightweight pullies - 9.5 lbs
intake - 4 lbs
removed fog lights - 5.5 lbs
removed cruise - 2 lbs
switch to small battery - 16 lbs
Flywheel - 9 (switched to aluminum flywheel)
remove radio/speakers/amp - 8 lbs
gas (¼ tank instead of 3/4) - 56 lbs

Like I said I did this for racing purposes and didn't measure fuel economy. I can tell you that I average 28mpg with my race car ('95 240sx), and 23mpg with daily driver ('96 240sx) when driving both cars normally. One is OBDI vs OBDII so that comparison should be taken with a grain of salt.

According to the SAE,your weight reduction would be good for a 3% improvement in mpg for mixed driving.