Lightened Yaris

[HTM Yaris]

Let me clarify . The center of gravity I was referring to is in the transverse plane ( up, down ) . All of the mentioned weight removal is below the window line , thus making a top heavy car . A top heavy car with a large cross section on a windy , icy day will not be safe . When considering weight reduction all three planes( coronal , sagital , and transverse) must be taken into consideration .

Also I meant to remove pass. seat . So if you have no pass. seat ...no pass. airbags are needed . I don't know about legality , but I do now that I've never heard of anyone asking to see the airbags when being pulled over .

Thanks for the battery tip

[docB]

What has all of this weight loss done for the ride quality? Everything you mention, save the light wheels is sprung weight. Rotating parts are really good things to put on a diet. I light weight flywheel would cut the pounds and pep up throttle response. Don't forget to loose the plastic engine cover. I did not weigh it, but I like taking wt off of those front wheels.
doc

[why?]

Originally Posted by HTM Yaris

Let me clarify . The center of gravity I was referring to is in the transverse plane ( up, down ) . All of the mentioned weight removal is below the window line , thus making a top heavy car . A top heavy car with a large cross section on a windy , icy day will not be safe . When considering weight reduction all three planes( coronal , sagital , and transverse) must be taken into consideration .

Also I meant to remove pass. seat . So if you have no pass. seat ...no pass. airbags are needed . I don't know about legality , but I do now that I've never heard of anyone asking to see the airbags when being pulled over .

Thanks for the battery tip

i understand, but losing 111lbs does not make the car top heavy. The driver alone probably weighs that much, never mind the engine weighs that much, and the roof simply does not. At some point, yes, you would have to worry about the car being top heavy, but it would have to be a very significant weight loss because the roof simply does not weigh that much.

As for the airbags, in mass if the airbag light is on, the car will not pass inspection. Since the car comes with a passenger airbag, in my state it must be installed or you cannot drive the car on the street.

I'd be shocked if it wasn't the same way in most NE states, and the other states that seem to follow cali in lockstep. It is just worthwhile to check out the laws before doing anything like that to make 100% sure you can do it and still drive the car legally.

Originally Posted by docB

What has all of this weight loss done for the ride quality? Everything you mention, save the light wheels is sprung weight. Rotating parts are really good things to put on a diet. I light weight flywheel would cut the pounds and pep up throttle response. Don't forget to loose the plastic engine cover. I did not weigh it, but I like taking wt off of those front wheels.
doc

I don't think it has hurt ride quality, and it definitely makes the car more fun to drive.

[HTM Yaris]

I say the roof weighs close to 300 lbs ( actual roof , glass, hatch, and panels etc) , but I doubt anyone will cut off their roof so we could find the exact weight

Also by definition any time you remove weight from the center of any object it makes it top heavy . You are correct in thinking the Yaris won't tip over at every turn by losing 111 lbs , but I am correct in saying it won't be a fun drive in a lightened Yaris on a 12 % grade in icy/windy conditions . Not to mention big rigs blowing past you and pushing you around .

To answer the ride quality question , the heavier Yaris will give the better ride quality . Go try it out for yourself . Just ride in you Yaris by yourself . Then ride with 1 or 2 adult passengers in the back seat . You will feel the difference fo sho .

Here in South Carolina , we don't have car inspections . But if we did and I wanted to remove the pass. airbag , I would be smart enough to remove the indicator bulb as well

Oh about the flywheel , true you can lose a lot of rotating mass , but the trade off is drivability . IMO the stock Yaris flywheel is perfect . With a light weight flywheel you will have to "blip" the throttle to match revs to make gear transitions smooth . With the stock flywheel the weight of it keeps the momentum up making gear changes much smoother .

[why?]

Originally Posted by HTM Yaris

I say the roof weighs close to 300 lbs ( actual roof , glass, hatch, and panels etc) , but I doubt anyone will cut off their roof so we could find the exact weight

Also by definition any time you remove weight from the center of any object it makes it top heavy . You are correct in thinking the Yaris won't tip over at every turn by losing 111 lbs , but I am correct in saying it won't be a fun drive in a lightened Yaris on a 12 % grade in icy/windy conditions . Not to mention big rigs blowing past you and pushing you around .

To answer the ride quality question , the heavier Yaris will give the better ride quality . Go try it out for yourself . Just ride in you Yaris by yourself . Then ride with 1 or 2 adult passengers in the back seat . You will feel the difference fo sho .

Here in South Carolina , we don't have car inspections . But if we did and I wanted to remove the pass. airbag , I would be smart enough to remove the indicator bulb as well

Oh about the flywheel , true you can lose a lot of rotating mass , but the trade off is drivability . IMO the stock Yaris flywheel is perfect . With a light weight flywheel you will have to "blip" the throttle to match revs to make gear transitions smooth . With the stock flywheel the weight of it keeps the momentum up making gear changes much smoother .

I can't say anything to 12% grades or seriously windy conditions, as I don't think I've ever driven on a grade that steep for anything longer than an 1/8 mile or less probably, I have never had a problem with wind at all with the Yaris. And I've never had a problem driving by big rigs, something i did a ton of when I drove from orlando to mass.

You are technically right about ride quality. That depends what type of ride quality you are looking for. If you are looking for super cushy, then don't touch anything. I have had 3 people or more in my car 2 times in the 4+ years I have owned it. I enjoy the ride better with all the crap out of it, where I here all the road noise and stuff hitting off the bottom of the car. I find that cool.

You're funny. In Mass, they attach the car's computer directly to an inspection computer, so they'd see the code.

The thing about rotating mass is spot on. Lightened pulley's and a lighter flywheel make the car harder to drive, and make the idle kinda nutty. For me the trade off is worth it, for others, maybe not.

[Idahotom]

CG?? Not enough to matter, besides I'd bet the CG is pretty much AT the seat level, what with the heavy engine and running gear. I had a high cross wind the other day, and yes I did get pushed around some, but do not know how it compared to a fully loaded HB as I am new to the genre.

The thing I really like is how well it coasts: I have a few places on a road I drive a lot, where I can put it in neutral, and maintain the speed limit for a mile, only slowing as I near a stop sign, as the slope pretty near matches the drag. I've done this for years in all my rigs on the same road, but the Yaris, probably mostly because it appears to be a pretty low drag rig, goes the furtherst.

Just today I went down the mountain (1,000' drop), into town 12 miles at 49 mph (on a state road posted at 45 that everyone drives 50+) and all around town running errands, then the same in reverse (not the gear, but order). 39 miles according to the calibrated Scan Gauge, and 51.8 MPG. No radical techniques were used just mild/unnoticable to others basic hypermiling. Windows down with the extra drag of the dog hanging his head out.

[HTM Yaris]

yeah I love to drive by myself without the radio on just to hear all the car sounds .

I have notices that the Yaris utilizes the slipstream(drafting) very well . I mean staying a few car lenghts back not right on the bumper . I'm always finding myself "easin" up on the gas when someone is in front of me , b/c Yaris sneaks up on the vehicle ahead of me .

[Jason@SportsCar]

Our car is down to 1860lbs... The only thing trying to make it tip over the is sticky Goodyear racing slicks. Lighter is better.

[ctrj]

What are getting for fuel mileage with all of the weight reduction? Pencil and paper calcuations only, Scan Gauge numbers do not count!

[why?]

Originally Posted by ctrj

What are getting for fuel mileage with all of the weight reduction? Pencil and paper calcuations only, Scan Gauge numbers do not count!

so accuracy doesn't matter? lol.

[scape]

I think as tempting as it is to lighten the rear, I personally would prefer to do this only if I planned to tweak the suspension a bit. having an even heavier front end seems silly without tuning the car further.
I do think lightening the front needs less tuning overall, and has an even more drastic impact.
anyways, you can always add your notes to this thread: http://yarisworld.com/forums/showthread.php?t=17526

I was hoping we could get more of these calculations on the forums :)

[Idahotom]

Originally Posted by ctrj

What are getting for fuel mileage with all of the weight reduction? Pencil and paper calcuations only, Scan Gauge numbers do not count!

Keeping in mind I have only had my Yaris home for 3 weeks, but had a Scan Gauge on an earlier car ('98 Honda Civic, 38 mpg) so am somewhat experienced at the milder forms of hypermiling, I am getting 42 t0 43 mpg. Checked at the pump (the same pump everytime), the station I use is still 100% good old gasoline, no ethanol. Other then the weight reduction, all I have done is run the still stock tires at 44 PSI. I also use my cruise control almost all the time, even in town on long stretches (mile or so) of 35 to 45 mph streets, pretty flat though. I also use it on the interstate, even when hilly, I just like the convinence.

Having to pull a 1,000' grade every day to get home, for me anyway it makes sense and just feels right to not haul any dead weight up with me. I also like not having it with me when going down, it is a win/win. If all I did was level driving I wouldn't be quite so anal about it. I even made a point of getting a small dog, 20 lbs, and keep him on a strict diet. Sure, people tell me all the time "that dog looks like he's starving", but every little bit helps. Making him run uphill helps keep the weight down also.

[scape]

Originally Posted by Idahotom

I even made a point of getting a small dog, 20 lbs, and keep him on a strict diet. Sure, people tell me all the time "that dog looks like he's starving", but every little bit helps. Making him run uphill helps keep the weight down also.

hahaha ;)

[KrazyDawg]

Originally Posted by Idahotom

I even made a point of getting a small dog, 20 lbs, and keep him on a strict diet. Sure, people tell me all the time "that dog looks like he's starving", but every little bit helps. Making him run uphill helps keep the weight down also.

Don't forget about your own diet. ;) It's not fair to the dog. :(