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Discussion Starter · #1 · (Edited)
I have been thinking about this, GM seems to screw typical EV convention by putting very wide tires on all the new EV's, Even the Standard Equinox is said to come with 255 wide tires, I am surprised GM is not going the way of Ford, with pizza cutters like the Mach E at 225, this makes difference in weight, drag, and aerodynamics, I would think the pizza cutters (old slang from my neighborhood for people with skinny tires on their cars) would be beneficial?

Hummer 355 wide
Lyriq 275
Blazer 275
Equinox 255-275

ID4 235-255
Mach E 225 GT 255
Tesla Y 255
Tesla 3 SR+ 235
 

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Bolt has a curb weight of 3500lbs, any standard road tire x4 has that capacity. When you star climbing up the weight scale cords/belts, compounds, sidewall thickness has to change to support the load.

Edit: Bolt = Michelin Energy Saver A/S 215/50R17

What I am waiting for is what is coming from Pirelli with the P-Zero Elect for larger EV SUV's
 

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Steam rollers vs pizza cutters, Hummer barely makes the steam roller category with 305. Could it be maybe they are in contract with Goodyear, but Goodyear does not have any EV/XL load rated pizza cutters? Just guessing here.
The Hummer 305s are narrower than 35s on Raptor/Bronco/wrangler (315) and TRX (325). 35s look pretty goofy when much narrower than 12.5” (~317), which seems to be roughly the standard for 35s.

Edit to add Tesla Model X are 265f/275r while the S is 265/295 when you opt for 21s.
 

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Discussion Starter · #9 ·
The Hummer 305s are narrower than 35s on Raptor/Bronco/wrangler (315) and TRX (325). 35s look pretty goofy when much narrower than 12.5” (~317), which seems to be roughly the standard for 35s.

Edit to add Tesla Model X are 265f/275r while the S is 265/295 when you opt for 21s.
S and X make my point, 275 on a mid level equinox or Blazer seem big, compared to Tesla's flagship cars.
 

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The Hummer 305s are narrower than Raptor/Bronco/Wrangler Extreme Rexon (315) and TRX (325) 35s. 35s look pretty goofy when much narrower than 12.5” (~317), which seems to be roughly the standard for 35s.
S and X make my point, 275 on a mid level equinox or Blazer seem big, compared to Tesla's flagship cars.
Have we heard anything on what the GMs weigh? Looks like the Lyriq is 5642 per C&D (vs Model X at ~5500). Wouldn’t surprise me if the Blazer weighs more given GM’s inability to “add lightness” to the Hummer.

Having spent almost $500 (including install) to replace a Model X front tire this week, not necessarily a fan of wide for wide’s sake!
 

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Discussion Starter · #12 ·
Have we heard anything on what the GMs weigh? Looks like the Lyriq is 5642 per C&D (vs Model X at ~5500). Wouldn’t surprise me if the Blazer weighs more given GM’s inability to “add lightness” to the Hummer.

Having spent almost $500 (including install) to replace a Model X front tire this week, not necessarily a fan of wide for wide’s sake!
Not surprisingly the Hummer body is almost all steel, only the tailgate seems to be aluminum. Surprisingly even the door skins are steel. Many GM cars have aluminum doors.

I get the feeling early Hummers were made on soft tooling, Maybe later ones will incorporate different materials.

Model X is nearly all aluminum, chassis and body. Lyriq and Blazer likely around the same weight, I expect AWD versions around 6000 lbs. Lyriq might be 100 lbs heavier than Blazer, due to extra features and sound deadening.
 

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Discussion Starter · #14 ·
Sorry I don't want skinny-ass tires on a Hummer. Screw gas mileage, it weighs 9000+ lbs, it needs some support and the look.
Agree, I hate pizza cutter tires on any car... They look weak. I am not looking for that last 5 miles or range where the tires make a difference.
 

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Recent rolling resistance research has shown increased rim width LOWERS rolling resistance when the tire is properly inflated and loaded, thanks to the stiffer sidewall and less hysteresis. 2% average RR improvement for each 1” width.

Applies w/ cycling, too. Pros used to race on 22 or 23 mm tires. Now most top TdF teams use 25-28 mm tires at a lower pressure than before. The lower pressure improves road compliance, which reduces contact resistance, and larger contact patch improves handling.

But for max range, the vehicle has to be designed w/ a wheel well sized for the tire. The aero design around the wheel well is very sophisticated now, requiring tires/rims coordinated w/ the well venting system to not create low pressure spots and maintain attached airflow along the fender and door panels. I think Michelin made special tires for the Lyriq.
 

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Discussion Starter · #16 ·
Recent rolling resistance research has shown increased rim width LOWERS rolling resistance when the tire is properly inflated and loaded, thanks to the stiffer sidewall and less hysteresis. 2% average RR improvement for each 1” width.

Applies w/ cycling, too. Pros used to race on 22 or 23 mm tires. Now most top TdF teams use 25-28 mm tires at a lower pressure than before. The lower pressure improves road compliance, which reduces contact resistance, and larger contact patch improves handling.

But for max range, the vehicle has to be designed w/ a wheel well sized for the tire. The aero design around the wheel well is very sophisticated now, requiring tires/rims coordinated w/ the well venting system to not create low pressure spots and maintain attached airflow along the fender and door panels. I think Michelin made special tires for the Lyriq.
Interesting, that seems to go against EPA testing, which typically drops with larger tires and wheels on most vehicles
 

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Interesting, that seems to go against EPA testing, which typically drops with larger tires and wheels on most vehicles
You have to account for inertia also, increase in weight uses more power to keep them spinning. More weight near the diameter of the tire has an adverse effect on range.
 

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My first EV was a Mitsubishi iMiev, which I owned for 5 years: you should’ve seen the teeny weeny tires it had! Kinda wish I had saved it for a photo next to my HEV 3X whenever I get it. Would be hilarious ! (Btw it’s amazing the advancements made in EV’s since 2012: my iMiev had 70 miles range when brand new, which slowly deteriorated to 35 miles range, since the battery had no temperature modulation. My Bolt EV has 266 miles of range which is still a good number!). It will be hard to imagine having over 300 miles of range on the Hummer …. My first charger was only 16 amps and wasn’t much faster than just using level 1. It had chademo DCFC, which was ridiculously fast! I have a 32 amp charger for the Bolt EV , and might have to get a bigger one for the Hummer EV, lol
 

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Discussion Starter · #19 ·
My first EV was a Mitsubishi iMiev, which I owned for 5 years: you should’ve seen the teeny weeny tires it had! Kinda wish I had saved it for a photo next to my HEV 3X whenever I get it. Would be hilarious ! (Btw it’s amazing the advancements made in EV’s since 2012: my iMiev had 70 miles range when brand new, which slowly deteriorated to 35 miles range, since the battery had no temperature modulation. My Bolt EV has 266 miles of range which is still a good number!). It will be hard to imagine having over 300 miles of range on the Hummer …. My first charger was only 16 amps and wasn’t much faster than just using level 1. It had chademo DCFC, which was ridiculously fast! I have a 32 amp charger for the Bolt EV , and might have to get a bigger one for the Hummer EV, lol
Hummer has way over 300 miles of range unless you are on an all highway road trip, in typical mixed driving around home, I am close to 400 miles of range, well over 300 charging to 80%.
 

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Hummer has way over 300 miles of range unless you are on an all highway road trip, in typical mixed driving around home, I am close to 400 miles of range, well over 300 charging to 80%.
Good to hear… I suspected that would be true for me, since my truck needs are simple: trips for greenhouse/chicken supplies, and going to the rubbish transfer station. Although I have gone on several 4 WD roads: up to the Mauna Kea summit, and down to Waipio Valley. There’s a couple 4WD trails I want to try with my Hummer EV 3X when it arrives: Green Sand Beach down at South Point for example.
But, yeah, we don’t have any freeways on the island, so I expect my mileage will be really good.
 
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