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Is that supposed to be 1/4 of the vehicle weight times the load rating? That doesn't make a lot of sense to me. 1/4 of the vehicle weight should be less than the load rating, I'd expect.
Ah - I bet I know what happened - I'll bet you had a "less than" sign in the middle of that formula and because that's a special HTML character it got stripped out by the forum software.
 

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Is that supposed to be 1/4 of the vehicle weight times the load rating? That doesn't make a lot of sense to me. 1/4 of the vehicle weight should be less than the load rating, I'd expect.

I'll use real examples, as I can see my from-memory quote of someone else's figuring could be confusing.

Forgive the non-Bolt numbers, I like easy math. ;). Also, ignoring the axle load considerations.


A 10000lb truck with 4 tires that each support a max of 2500lbs at 80psi max sidewall rating would need 10000 divided by (4 times 2500lb) would use a ratio of 1 for the tire pressure. So I would inflate the tires to 80psi in this case (ie, max rating as listed on the sidewall).

A 5000lb truck with 4 tires that each support a max of 2500lbs at 80psi max sidewall rating would need 5000 divided by (4 times 2500lb) would use a ratio of 1/2 of the max rated tire pressure. So 40psi in this case is what the math says and I would personally make a decision to run a higher number in real life if that was a real world example.


Clearer?
 

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I'll use real examples, as I can see my from-memory quote of someone else's figuring could be confusing...
OK, if I understand your logic correctly, the OEM tires on the Chevy Bolt are rated for 1356 pounds of load and a maximum inflation pressure of 44psi. The gross weight of the Bolt is 4515 pounds. So according to that formula the pressure should be 4515 / (4 x 1356) which is 36.6 psi. Close, but a little lower than the 38 psi recommended on my door sticker.
 

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Linear extrapolation is usually a little conservative, too. If you buy tires that have actual load tables from the manufacturer, the weight rating does not regress linearly with lower pressure, but along a slight curve; so at 75% sidewall pressure you might have something like 82% weight rating available for a given tire. Linear is usually a safe way to do things though from what I have been led to believe over the years.
 

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OK, if I understand your logic correctly, the OEM tires on the Chevy Bolt are rated for 1356 pounds of load and a maximum inflation pressure of 44psi. The gross weight of the Bolt is 4515 pounds. So according to that formula the pressure should be 4515 / (4 x 1356) which is 36.6 psi. Close, but a little lower than the 38 psi recommended on my door sticker.
Awesome.

Plus passengers and groceries on top of the 4515 would likely get somewhere close to 38psi.
 

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15" Tires on Bolt?

New to the forum and am very excited to receive my Bolt next week! Because I'm Canadian, the first thing I'm going to do is put ugly steelie rims on with fat winter tires!

My trade-in has a set of almost brand-new 160/60/R15 XIce tires. Dealer had a deal showing that 15" rims will fit the Bolt - but because I have my own, why buy it from the stealership?.

Can anyone here verify that a set of 15" rims will indeed fit?

Thanks in advance!

Joe
 

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And I'm assuming the 15"s you have now have the bolt pattern and offset that works for the Bolt/Cruze/Sonic/Volt gen2.
I'll need to get new rims with the right offset, hub-diameter, and bolt patterns for the Bolt (no pun intended). But a set of steelies will set me back maybe $150 vs. having to buy new winter rubbers.

Thanks for the confirmation!! Wheww!
 

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Linear extrapolation is usually a little conservative, too. If you buy tires that have actual load tables from the manufacturer, the weight rating does not regress linearly with lower pressure, but along a slight curve; so at 75% sidewall pressure you might have something like 82% weight rating available for a given tire. Linear is usually a safe way to do things though from what I have been led to believe over the years.
what about NOKIAN WRG3
215/50R-17

https://simpletire.com/nokian-215-50r17-t428628-tires

I did a little too much sliding down a mild hill in fresh snow. Was in regen mode.
I guess regen is bad for snow/down hills?
I drive for Lyft..
 

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I did a little too much sliding down a mild hill in fresh snow. Was in regen mode.
I guess regen is bad for snow/down hills?
I drive for Lyft..
Regen mode caused your tires to lose traction going downhill? Was it quick release off the pedal or just easing off?

If it was when just easing off, that is disconcerting. I have always used low gear in an ICE to slow down on downhills had done so in my B-Class EV & LEAF and and figured to do the same in the Bolt.
 

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Regen mode caused your tires to lose traction going downhill? Was it quick release off the pedal or just easing off?

If it was when just easing off, that is disconcerting. I have always used low gear in an ICE to slow down on downhills had done so in my B-Class EV & LEAF and and figured to do the same in the Bolt.
I didnt touch the brake at all since I was on regen mode... but the car still slid... WITH passengers in there car.
I assume its because the torque was trying to keep the car slower than the inertia ... but alas I am not an engineer
 

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When braking in a normal car at moderate levels of deceleration, the counter-torque applied to the wheels/tires is shared between the front and rear tires of the car, with the front doing about 70% of the work, typically. However, in 2WD/FWD EVs all that regen torque has to go through the front wheels to decelerate (not shared with the rear wheels), when driving in LOW.

So, my advise would be to drive in "D" in slippery conditions and allow the car to use the friction brakes once the front as hit its regen limit. When in "D" the maximum amount of regen is limited to some amount (~15 kW?). I can't remember..but it's way less than what I see in "L". I think I've seen as much as 70 kW of regen while in LOW!. Those aren't exact numbers so feel free to correct me.
 

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Also posted at one of the other winter threads:
After all the discussion I decided to go out and do a bit more real world testing. Bizzak winter tires, temperatures near 0 F. All the side streets in town are snow/packedsnow with glazed surfaces at some of the intersections. I 90 up to Homestake Pass is mostly clear, a couple shaded spots can be a bit iffiy. The road in to Homestake Lodge, 6 mile RT is solid snowpack. Using L and aggressive regen I was able to lose traction at a glazed intersection. The AntiLock system seems to work fine. I didn't experience any bizarre noises and if glazed enough I was able to make it struggle a bit as well. I found a snowpacked hill with some glazed surfaces and again was only able to lose traction using aggressive regen in L. Normal driving in either L or D was not a problem and he AntiLock brakes did fine. I drove in and out to Homestake Lodge using both D and L and was actually morecomfortable using L, plus I think I was a bit more energy efficient in L. At temperatures closer to freezing I might be more inclined to use D, but at these colder temperatures and a consistent snowpack, L has worked fine.

Bottom Line. Test these possibilities out with your own driving style, comfort and tires and do what you're most comfortable with. If you're not paying close enough attention to road conditions and temperature, it's not going to matter and difficulties may arise.
 

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I'm looking at picking up either Nokian WRG3 or Toyo Celsius. These are All-WEATHER (not all-season) tires. They have the snow-flake "snow" rating on the tires. I had a set of the WRG3 on a prior car and they were excellent even in heavy snow/slush/ice conditions here in Jackson, Wyoming. Not having to change tires in summer is great, even if tires don't last quite as long. The factory tires certainly are wearing quickly according to reports. Not having to spend $100 twice a year to change out tires is worth it to me, even if I lose a bit of range. If range decrease is significant, I can always put the factory tires back on.

Jim

Jim, would love to hear what you came up with. If you ever sign in here again.



Your car, your money, your decision, based upon your experience. Just know that objective tests by independent organizations will show "all-weather" tires do not start/stop/turn as well in heavy snow/slush/ice conditions as do real winter tires.

Yes, that's why "all-season" tires exist. They're more convenient and more economical; just not as good in the worst conditions.

jack vines


Not aimed at Jack, but he speaks some truth, so repeating.



I just today got a set of Toyo Celsius put on. A bit of freezing rain overnight has turned the side roads somewhat slick but not into shear ice. Had a bit of slip on the way to the tire shop on the un-plowed roads with the factories. Tried out the new tires on an unplowed parking lot with about 4-5" of snow. The car was confident in stopping/starting/pulling out from the snow areas, whereas the factory tires would have been less capable. Temps about at freezing.

Personally, I would rate them as a solid 7.5 stars for winter tires but I only have 8 miles on them too. I figure the 4x4 with BFG's can play in the heavy snow. >:)
 

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It's time to think about winter tires. Our Bolt's run a tire size of 215/50/R17, whether you want to run that or a size you figure is better is up to you. Use this thread to compare and discuss sizing, pricing, brands/models, wheel/tire packages, comparisons, reviews, where to buy, etc.

Starting this thread off i'm keeping myself open to the following three winter tires:
  • Dunlop Winter MAXX
  • Michelin X-ICE XI3
  • Pirelli Winter Sottozero 3
You should add Nokian WRG3's . Rated for Wet, Slush and some snow, my car now handles like a corvette
 

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If you need an additional set of TPMS sensors- the set of four are available on ebay for $57 including shipping.

Search ebay for "22854866".

So, others have said that they got a 15" steelie package from Tire Rack. I cannot get a 15" option when I enter 2018 Bolt EV Premier (only 16 & up are offered). If I 'pretend' that I have a 2019 Chevy Sonic Hatchback, I can select 15" steelies and upsize the tires to 205/65R15 (0.11% off of OEM diameter.) I also can select to add TPMS. If I go to one of the ebay offerings of "22854866", I can find those that claim they are compatible with my 2018 Bolt EV and it also claims a 2019 Sonic Hatch to be compatible. Anyone else confirm this should work?
 

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I'm surprised the steel option doesn't come up. What if you type in 2017 Bolt?
My invoice describes the wheels as: 15X6 5-105 ET39 ST NEW
Not sure if that helps or not.

To my knowledge, GM hasn't changed any brake related components between 2017 and 2018.
 

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Tire Rack says not compatible

So I chatted with one of the Tire Rack representatives and they said that they show the 15" steel wheel is not compatible. I pointed out that other Bolt EV owners have ordered that setup from TR in the past and in fact the lone reviewer of the 15" Sonic Steel wheel is a Bolt EV owner (raitchison I presume). They responded that I can order anything I want. Not sure I want to hedge $800 and deal with return/unmount fees if there is an issue. I wonder if they changed supplier for that wheel and now it interferes. Anyone else recently order a 15" steelie from TR?
 
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