was looking at Tirerack and noticed they had 20" wheels now for the Volt, other than a loss in range due to additional weight which when all said and done is like driving with a very slender lady, i'm still contemplating getting the larger and wider rears and the small 18's for the front to give it that sport drag look.

http://www.tirerack.com/images/wheels/platinum/swap/plat_saber_mba_ci3_l.jpg

I know some of you don't like to mod but what do you think for 20's on the back?

Stock rims are only 7" wide. Are you sure there is enough room for that extra inch of width?

There already isn't enough clearance for chains with the stock wheels, according to Chevrolet.

Whether there is room for width would depend on the offset of the rims. If TireRack says they will fit and they don't then it would be up to them to take them back.

Chains add extra height to the wheels, so maybe that's more of the problem. You might be able to modify the front wheel well covers to make room for the chains.

was looking at Tirerack and noticed they had 20" wheels now for the Volt...
I know some of you don't like to mod but what do you think for 20's on the back?

Wow. That would look super cool. Are you going to have to install special springs or are the current springs high enough?
:cool:

The overall diameter wouldn't change. The tires would be lower profile, so the springs don't come into play.


Wow. That would look super cool. Are you going to have to install special springs or are the current springs high enough?
:cool:

was looking at Tirerack and noticed they had 20" wheels now for the Volt, other than a loss in range due to additional weight which when all said and done is like driving with a very slender lady, i'm still contemplating getting the larger and wider rears and the small 18's for the front to give it that sport drag look.
I know some of you don't like to mod but what do you think for 20's on the back?
Perhaps you can find some alternate pictures that you could "photoshop" or the like on a car that is your same color.

The only thing I think would be a bit weird is the different wheel styles on the front and the back. Or is there the same style available in the smaller size for your front wheels?

Edit. Nix the above. Answered my own question. Wow, that's quite a website (tirerack.com)... They've got a LOT of wheel options for the Volt. I had no idea! Cool.

Yes, you can get the same style in large and smaller size. In fact on some wheel styles you could get 17 and 20 inch sizes. That would be sweet.

The only thing I think would be a bit weird is the different wheel styles on the front and the back. Or is there the same style available in the smaller size for your front wheels?

Its the same style just 18's on the front and 20's on the back, many European cars have this type of setup (Jag, Audi, BMW) as well as a few others here (Chrysler crossfire for one).

I also want to get the Ampera front bumper and lights and then get the lower side panels painted...but that will have to wait until they start to deliver the Ampera

Perhaps you can find some alternate pictures that you could "photoshop" or the like on a car that is your same color.

They do have a 'see it on your vehicle option' but they don't allow you to do two diff sizes and dont have the rear look etc etc...

Well, here is a quick work in GIMP (freeware photoshop equivalent).
However, would you get lower profile tires for the front as well? I think that would look better than this.https://lh6.googleusercontent.com/-PO4DfgBEn0M/TubgkcLvVdI/AAAAAAAAs0o/fY7lSjzfr9g/s912/20_inch_rear_wheels_and_18_inch_front_wheels.jpg

That would be a no, no. You want to stay pretty close to the original overall diameter so you don't confuse things like stability and ABS functions. So it would look strange with a 20 on the back and a 17 in the front given that the sidewall would be 1.5" different front to back.

Those wheels look good on the car in the photo. In real life, the rear brakes make look really tiny compared to 20" wheels that show a lot of caliper.



Well, here is a quick work in GIMP (freeware photoshop equivalent).
However, would you get lower profile tires for the front as well? I think that would look better than this.https://lh6.googleusercontent.com/-PO4DfgBEn0M/TubgkcLvVdI/AAAAAAAAs0o/fY7lSjzfr9g/s912/20_inch_rear_wheels_and_18_inch_front_wheels.jpg

I'd leave it stock. I've heard of one Cruz owner than had problems, too with fitting wider rear tires. (You could check out a Cruz forum for feedback, etc). I wasn't really thinking about new wheels but I did put my Volt up and lift and look around underneath, just because . . . . and there is not a lot of room in the wheel wells.
1) Most likely Chains won't fit because the wheel wells don't have a lot width and that's probably at least one place near the inner front (near the back of the battery pack) where they or wider tires would not have clearance: I've modified other GM cars to take wider rear tires (when they are really needed) and its a major operation. Here since they would do nothing, I've leave the stock width.

2) second, narrower tirewalls change the handling, particularly transient handling as you are turning the wheel, and I would expect with the Volt's lower center of gravity it would be more sensitive to that change than normal if you put even normal width 20"s on it.

Finally, the Volt is an electric car and not a drag car so the drag car look to me would seem strange for it. I plan to leave mine stock but look I think would be in character with the car's mission (efficiency) would be full streamlined (fully covered) wheels as on Bonneville land speed record racers.

Most likely the circumference of both front and rear wheels will be substantially different from stock. Also ride quality will be degraded. You'll also end up with speedometer and odometer errors on the plus or minus side, resulting in false energy efficiency outputs. While there are aftermarket devices that can correct for this, YellowBox for example - www.ybr.com, these may not work with the Volt speedo/odo setup.

I think most experts would advise not going larger than an 18" wheel, especially for ride quality. Also given the technological sophistication of the Volt there may be some other unexpected surprises, as others have suggested. So I would do a lot of research before spending the large dollars this will entail.

Circumference would be the same if you use one of those online tire size calculators to find the right tire size for 20" rim to keep the same diameter. That way you don't have to worry about speedos or other tech issues.

The Volt has a very soft ride in the suspension, so it probably wouldn't be noticeable for ride. And in terms of handling, you wouldn't see the difference unless you tracked the car (no one is going to that regularly, I hope).

I'd like to see more customization of the Volt. The aftermarket customization of cars is positive sign of the success and enthusiasm of a car - think Camaro, Mustang, or 300C.


Most likely the circumference of both front and rear wheels will be substantially different from stock. Also ride quality will be degraded. You'll also end up with speedometer and odometer errors on the plus or minus side, resulting in false energy efficiency outputs. While there are aftermarket devices that can correct for this, YellowBox for example - www.ybr.com, these may not work with the Volt speedo/odo setup.

I think most experts would advise not going larger than an 18" wheel, especially for ride quality. Also given the technological sophistication of the Volt there may be some other unexpected surprises, as others have suggested. So I would do a lot of research before spending the large dollars this will entail.

Circumference would be the same if you use one of those online tire size calculators to find the right tire size for 20" rim to keep the same diameter. That way you don't have to worry about speedos or other tech issues.

The Volt has a very soft ride in the suspension, so it probably wouldn't be noticeable for ride. And in terms of handling, you wouldn't see the difference unless you tracked the car (no one is going to that regularly, I hope).

I'd like to see more customization of the Volt. The aftermarket customization of cars is positive sign of the success and enthusiasm of a car - think Camaro, Mustang, or 300C.

Here is the difference in the tire sizes using 19 inch and 20 inch rims, which shows adding the right tire will offset the rim size and the overall impact to MPH etc is not that significant and within recommended tolerances

Stock Tire - 215/55R17
Section Width: 8.46 in 215 mm
Rim Diameter: 17 in 431.8 mm
Overall Diameter: 26.31 in 668.27 mm
Sidewall Height: 4.65 in 118.11 mm
Radius: 13.15 in 334.01 mm
Circumference: 82.65 in 2099.3 mm
Revs per Mile: 790.5
Actual Speed: 60 mph 100 km/h
Speedometer Difference: -
Diameter Difference: -

Tire 1 - 235/40R19
Section Width: 9.25 in 235 mm
Rim Diameter: 19 in 482.6 mm
Overall Diameter: 26.40 in 670.56 mm
Sidewall Height: 3.70 in 93.98 mm
Radius: 13.20 in 335.28 mm
Circumference: 82.93 in 2106.4 mm
Revs per Mile: 787.8
Speedometer1: 59.7 mph 99.6 km/h
Speedometer Difference: 0.342% too slow
Diameter Difference: 0.35%

Tire 2 - 235/35R20
Section Width: 9.25 in 235 mm
Rim Diameter: 20 in 508 mm
Overall Diameter: 26.47 in 672.33 mm
Sidewall Height: 3.23 in 82.042 mm
Radius: 13.23 in 336.04 mm
Circumference: 83.15 in 2112.0 mm
Revs per Mile: 785.7
Speedometer1: 59.6 mph 99.3 km/h
Speedometer Difference: 0.610% too slow
Diameter Difference: 0.61%

Most likely the circumference of both front and rear wheels will be substantially different from stock. Also ride quality will be degraded. You'll also end up with speedometer and odometer errors on the plus or minus side, resulting in false energy efficiency outputs. While there are aftermarket devices that can correct for this, YellowBox for example - www.ybr.com, these may not work with the Volt speedo/odo setup.

I think most experts would advise not going larger than an 18" wheel, especially for ride quality. Also given the technological sophistication of the Volt there may be some other unexpected surprises, as others have suggested. So I would do a lot of research before spending the large dollars this will entail.

Interesting. Given the whole computerized aspect of the Volt, don't you think GM could pre-load it with different speedometer/odometer/ABS/traction control profiles for different wheels/tires? When you have a GM-certified technician install the wheels/tires, they would select the corresponding profile.

You could even have an info screen that would tell you "if you choose such-and-such wheel, your all-electric range may approximately decrease by ___, but be sure to have your technician select the profile that corresponds to the wheel/tire size you choose." etc.

HEY. IMHO that's a cool idea.:cool::cool::cool:

In other words, the VOLT should be more FREEDOM than electric. WAY COOL.

Logical,

Your sig says you are waiting to buy the Volt with cash in August. Any idea how much extra that would cost you versus financing for a year? How much are you losing a month in gasoline? And now volts are selling for $1000 below invoice which may not last when the histeria of battery fires dies down. Could be significantly cheaper for you to buy now than August.

And you can get your $7500 rebate a year sooner if you pull the trigger right now.

Logical,

Your sig says you are waiting to buy the Volt with cash in August.

The Question is somewhat off topic.... but since you ask...

If I were purely trying to save on costs, well, it costs less stick with an old highly-reliable $2000, 40mpg ICE car for the rest of my life. But I want a Volt for all the good reasons we all know.

Thus, why would I buy in cash? There are other benefits of buying the car in cash, such as increased negotiating power of cash (real deals can be had by flashing the cash at the right moment). But yes, maybe I would be saving money that I would simply save on gas now. So that's not all. It's more about my financial philosophy.

I like the security of not owing anything on the car. Owe nothing = be free. The bank has no power over me. I like the satisfaction of knowing I literally bought it with cash I had already earned, etc.
There's this fairly common sense financial guy whose ideas I like: Dave Ramsey. Some of his underlying principles are: Plan your life. Happen to it. Don't let life happen to you. Within this concept is the idea: don't buy anything you don't have cash for.
http://www.daveramsey.com/new/baby-steps/

Incidentally, when you are physically giving some dealer forty $1,000 bills, it REALLY feels like $40,000... Not so much twinge as signing a loan. So to me, paying in cash allows me to affirm my absolute belief that this car is the ONE car on the market that has even HALF a SHOT at making me feel it's worth $40,000. All the other luxury cars are marketing jokes. That's just IMHO.

Since you asked. :) But I respect everyone's right to their own opinion.

Logical, I think your well within your rights, and make a great point. :) I want to do these wheels guys, don't it look great! And then I want to take off my lower gray panels and have them painted gloss black to match the wheels. And I want the glossy black caliper covers with Volt on them. :)

4093

Only problem is they aren't 20", I'd like 20's. I saw the measurements and once you go bigger it's such a small increment after that. :) It would look very impressive!

@Britt1, I like the look of the 20" wheels. My personal taste prefers all of the wheels to be of the same size, so I would probably opt for 18's all around vs. 20" out back and smaller out front, but that's just me. I would expect, as many have pointed out, there will be trade-offs for attaining this cosmetic enhancment, including possibly compromises in handling, ride quality, speedometer accuracy, and EV range. Although some of these effects might be negligible and it's a personal choice whether or not these are reasons enough to disuade you from making the change. But if you do go for it, I would be interested to see a before/after report on how much (or little) difference it made, particularly to your EV range. In addition to the increased weight, you'll also have increased rolling resistance even if you keep the overall diameter the same due to the increased tire width and material friction coefficient (I haven't checked if the FuelMax tires are available in larger sizes so I'm assuming here that you'd be using a different type of tire with different material properties).

Best of luck.

@Britt1, I like the look of the 20" wheels. My personal taste prefers all of the wheels to be of the same size, so I would probably opt for 18's all around vs. 20" out back and smaller out front, but that's just me. I would expect, as many have pointed out, there will be trade-offs for attaining this cosmetic enhancment, including possibly compromises in handling, ride quality, speedometer accuracy, and EV range. Although some of these effects might be negligible and it's a personal choice whether or not these are reasons enough to disuade you from making the change. But if you do go for it, I would be interested to see a before/after report on how much (or little) difference it made, particularly to your EV range. In addition to the increased weight, you'll also have increased rolling resistance even if you keep the overall diameter the same due to the increased tire width and material friction coefficient (I haven't checked if the FuelMax tires are available in larger sizes so I'm assuming here that you'd be using a different type of tire with different material properties).

Best of luck.

I think I'm actually going to go with 19's all round, with the right tire choice I can keep the correct overall diameter of the current 17's. It will also cut down on weight. I suspect the overall impact to be negligible to the MPG and Battery range. I just need to find the right rims now.

I also want to paint the lower side panels but haven't had any help off the board on the removal procedure for those as yet, I did ping WOT via a PM so I'm hoping he can help me out.

I paid cash for mine, it does help with dealing, but there's not much margin to work with on a Volt (though there might be on any trade in). I just wrote a check though. Funny, it's hard to write a 40k check since they tend to be too stupid to round numbers, so you wind up writing a lot of digits...even pennies!

For the same overall diameter, a larger wheel and a lower profile tire weighs LESS, not more, which is why the whole big wheel thing came into existence in the first place. Ask any racer about that one, but look - aluminum is stronger per pound than rubber, duh. A wheel is mostly air, not thick rubber....At any rate, I doubt I'd change mind, as the sprung to unsprung weight ratio and suspension seem just right as is for what we get.

As any drag racer would point out - having to accelerate the wheels not only in a straight line, but round and round takes a lot of excess energy...in our case, it's probably not real important but it's a factor in racing where they don't have regen braking to get it back.

But I'd love to find some flame decals to stick on mine - I DO have a sense of humor, and that would add more to the looks, eh?

My experience is that cash does not help you to get a better price for a new car. In fact, it's probably the opposite. I believe the sales reps get an extra bonus if you finance through the dealer so they may have more wiggle room on the price of the car. They can come up with some pretty good finance rates if you have good credit.

You're problem may be the bad credit, so you would have to go the cash route.

As far as the Volt not having a lot of margin, the ads for $5000 off MSRP that came after the adds for $2000 and $3000 and $4000 off MSRP would suggest otherwise.

Unless the stock 17" wheels are unusually heavy it's hard for me to imagine that 20" wheels will save weight. Usually, the larger the wheel the more it weighs. But again, the stock wheels could be very heavy.

Unless the stock 17" wheels are unusually heavy it's hard for me to imagine that 20" wheels will save weight. Usually, the larger the wheel the more it weighs. But again, the stock wheels could be very heavy.
your set is now off right? I think you may need to take the scale down to the garage and give us the lowdown on the stock wheel/tire weight :)

Unless the stock 17" wheels are unusually heavy it's hard for me to imagine that 20" wheels will save weight. Usually, the larger the wheel the more it weighs. But again, the stock wheels could be very heavy.


Designing-the-Volt-Six-ways-it's-different-from-your-car
http://gm-volt.com/forum/showthread.php?8677-Designing-the-Volt-Six-ways-it%92s-different-from-your-car

Reason No. 1: Aerodynamics.
<snip>
“The scoops in the wheels helps get rid of the extra material. They’re very low mass. The geometry of those wheels actually helps with the aerodynamics. They send air out or in as they rotate, and air going in under the car is very bad for aero.”

Stock wheels are 17lbs which is light for 17" wheels but not crazy light. Anything bigger 18+ will be over 20lbs. I haven't seen any hard data on what the heavier weight can do for range.

Stock wheels are 17lbs which is light for 17" wheels but not crazy light. Anything bigger 18+ will be over 20lbs. I haven't seen any hard data on what the heavier weight can do for range.

yeah, I'm looking for the Wheel/Tire combined weight. id imagine that its a few pounds heavier

yeah, I'm looking for the Wheel/Tire combined weight. id imagine that its a few pounds heavier

You can get the tire weights with a quick look on the specs for each tire on TireRack. Don't expect a little less sidewall to make up for the heavier rims. Most of the tire weight is in the tread and the bead, not the sidewall.

I also want to paint the lower side panels but haven't had any help off the board on the removal procedure for those as yet, I did ping WOT via a PM so I'm hoping he can help me out.

This might be one of those times voltage692 could have helped out since his "guy" seemed to do a pretty decent job. Hopefully WOT gets back to you.

Another note on the bottom side panels and such being painted. Since I want a high gloss black to match the plastic under the windows and the roof, I can have someone put black vinyl on can't I? That would be much cheaper and achieve the same look!

Another consideration is stress to the suspension components goes up as the sidewall height goes down, so larger rims have been known to cause cracking on some cars. I don't remember which Porsche it was that had the problem of cracks to the lower control rod or A-frame when customers changed the rims from 18" to 20". Apparently they had to issue a tech bulletin about it, basically saying don't do it, do it at your own risk, etc.

So changing rim sizes can cause problems down the road, whether it does or not is yet to be determined. In this case you are the engineer in charge of the modifications. I for one would not like to find out about a problem in a high speed corner...

Another note on the bottom side panels and such being painted. Since I want a high gloss black to match the plastic under the windows and the roof, I can have someone put black vinyl on can't I? That would be much cheaper and achieve the same look!

Vinyl wraps work great on smooth surfaces (paint and glass). The skirts are not smooth. The texture would be a problem.