How much more MPG can I get if I reduce cars weight by 44 pounds?

[cfg83]

ConnClark -

Originally Posted by ConnClark

Actually I read an article some place where some doctor was doing that.

Reminds me of Fight Club. They steal the hazmat liposuction fat to make boutique soap that they sell back the women that had liposuction, .

CarloSW2

[cfg83]

blackjackel -

Here is a total guestimate. First I would estimate the "on average" loaded weight of the car, and use this equation to express an inverse proportion relationship :

old weight X / new weight Y = new MPG ? / old MPG Z

Isolating for new MPG ? leads to this modified equation :

new MPG ? = ((old weight X) * (old MPG Z)) / new weight Y

Now let's plug in example numbers :

old weight X = 2800 lbs
new weight Y = 2800 - 44 = 2756 lbs
old MPG Z = 36

new MPG = (2800 * 36) / 2756 = 36.57 MPG => +0.57 MPG

But, this is all speculation on my part. Also, changing the weight of the wheels is a special weight change because it modifies the load on the engine. This sounds like a great tuner question. I think there are very pricey wheels out there that are light and strong for just this reason. I would look in the Sport Compact Car magazines to see what is offered for your Corolla.

CarloSW2

[tjts1]

Well heres my situation. The volvo 850 has steel wheels with plastic hub caps that are about as close to completely smooth as you can get from an OEM but they are about 10lb heavier than the same size 6 spoke alloy wheels. If I switched to alloys, will the 40lb weight loss offset the increase in aerodynamic drag from spinning wheel spokes?

Going from this


To this.

[whokilledthejams]

It depends on your driving. If the majority of your driving is done at city speeds, then yes, the alloys will help a whole bunch.

You can always get screw-on Moon discs. They are secured by three small screws per wheel that slightly enter the tire bead. Needless to say, using them on a daily-driven car sounds scary. It would be a different story if, say, you put them on a track-day car, and the track was a salt flat or dry lake.

[getnpsi]

i went to some honda vx wheels. On my application its a savings of 9 pounds per wheel+tire. I'm back to the stock tire size, so we shall see if there is a gain on this brand new tank. Remember the lighter your wheels/tires are your brakes should last longer as well, so its not just mpg's to consider. If you can go extra months with never taking your car apart that is money saved too. My aspire is a delivery car so the lighter i can get it the better, as i never see the highway more than 4-5 miles in any direction.

[digitaldissent]

I have wondered the same thing and started this thread a little while ago, might be helpful

http://ecomodder.com/forum/showthrea...loys-2681.html

check out ChrisD's experience with lighter wheels

[JJW]

Take a look on craigslist, certain model Mazda miatas came with wheels that are a fit for your yaris and are light.. I've seen them going for under 100 dollars for the set.

[apgrok1]

I'm going to throw another number out. I have heard that every 10% of weight reduction, you gain 8% in mileage. I saw this on a news report somewhere. I think it was a GM spokeman that made this claim.

[NeilBlanchard]

Hello,

What's the average MPG for a GM vehicle? Maybe the low 20's? The Aptera weighs ~1,400 pounds and has a Cd of 0.11 -- and it gets 130-340MPG.

I don't think GM has very much credibility...

[Smoove]

I think there are a lot of variables working to truly get you this number, but I will share my experience.

In my Jeep I drove without a spare or jack for 8 years, in a mix of 30% city, 70% highway miles. My wife started driving the Jeep when she was in between cars so I put the spare and jack back in and lost 1mpg - even after switching to 90% highway driving.

My Lincoln (1995 mark viii LSC) has undergone the same de-bloating over the last decade by me, and while the track times improved a bit the mileage never varied. I could pull 28mpg on that car easily if I could keep it under 70 and let the cruise control work its magic. It dips to 24 if I start driving the way I want to.

just my two cents.