JoeS
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Re: Wheels, Rims, and Tires

Mon Dec 30, 2013 5:50 pm

SPARE TIRE

With over 22K miles on our Mitsi I decided to swap left and right tires as the front left one is wearing a bit more on the outside resulting from my high-speed onramp/offramp escapades. Anyway, while I had the car up in the air I pulled out the 'temporary' spare tire from my Gen1 Honda Insight and tried it: it fits both the front and the rear! The bad news is that it is a 14" tire. Not to worry, I have two Insights so for longer trips I'll be packing both tires plus a lightweight jack plus wrench/socket, in addition to the collection of power connector adapters and extension cords and portable EVSEs... sheesh, over 100# of 'stuff' just to venture outside one's comfort zone in an EV. Hey, we thought our iMiEV front tires are skinny? - check out the photo of the Insight's emergency spare next to the iMiEV's front tire. The Insight 'temporary' spare is labeled T115/70014 88M and the very lightweight alloy wheel is labeled 14/4T 32. The car is up on jackstands in these photos.

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EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

Don
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Re: Wheels, Rims, and Tires

Mon Dec 30, 2013 6:33 pm

It looks like your tire is worn out, Joe - I can see the wear bars worn flush. Time for a new pair

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

MLucas
Posts: 833
Joined: Thu Jun 07, 2012 8:52 am
Location: Niagara on the Lake, Ontario, Canada

Re: Wheels, Rims, and Tires

Tue Dec 31, 2013 8:50 am

Looks like motorcycle tires.

JoeS, you must like to slide you I-MiEV around a lot. I've got close to 22k miles on my I-MiEV and still have plenty of tread left. ;)

The new i3 from BMW is equipped with the skinny tires. Another I-MiEV first copied by competition. Funny no one is complaining about them on a BMW.
http://www.greencarreports.com/news/1083080_bmw-i3s-tall-skinny-tires-to-boost-efficiency-and-cut-noise

Like Dylan...I went electric.

  • Purchased: June 29th, 2012
  • Mileage on June 29th, 2013 - 25,431 km / 15,802 miles
  • Mileage on June 29th, 2014 - 51,286 km / 32,616 miles

List of Oil Spills: http://en.wikipedia.org/wiki/List_of_oil_spills

JoeS
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Re: Wheels, Rims, and Tires

Tue Dec 31, 2013 9:30 am

Don wrote:It looks like your tire is worn out, Joe - I can see the wear bars worn flush. Time for a new pair
Don, thank you for pointing that out and if our record drought continues I could probably get by on slicks. :roll: Note the very even treadwear pattern despite running these tires at 60psi. Since I AM in the market for replacement tires (the default being our stock Dunlop Enasave) and I like my stock alloy wheels, my priority is a tire with the lowest rolling resistance, willing to sacrifice handling, noise, comfort, treadwear, etc. Anyone have any suggestions for the latest and greatest?

MLucas, I keep telling y'all that I live on a winding road and enjoy throwing our iMiEV around. Our iMiEV's low CG really makes it fun to drive in the hills; however, most of the miles are by my wife who is a sedate hypermiler. Perhaps running at 60psi has something to do with it? At least my tires fared better than the 12Kmiles Barb got: http://myimiev.com/forum/viewtopic.php?f=26&t=1490

MLucas wrote:The new i3 from BMW is equipped with the skinny tires. Another I-MiEV first copied by competition. Funny no one is complaining about them on a BMW.
http://www.greencarreports.com/news/1083080_bmw-i3s-tall-skinny-tires-to-boost-efficiency-and-cut-noise
Wonderful observation! Have to remember that one. :geek:
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

Don
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Re: Wheels, Rims, and Tires

Wed Jan 01, 2014 7:15 am

JoeS wrote:Note the very even treadwear pattern despite running these tires at 60psi
I think if you showed that tire to anyone with any expertise in tires, they would immediately tell you it has been run severely overinflated. All of the tread in the center is gone, while both outer edges still have tread - Pretty much the exact opposite of what you see on most worn out tires. The outer edges are designed to 'bite' in to prevent the tire from sliding sideways, so they are usually the first to go when the tire is run at the recommended pressure

I don't think you're gaining 1/10 of one percent in added range by running 60 psi over a more reasonable pressure like 45 or 50, but I do think it's costing you some in handling and definitely some tire wear. This car understeers pretty heavily, so it needs all the help in front that it can get. Keep in mind that your wife drives it the majority of the time and it's probably just your trips down the hill which caused this unusual wear. If you drove it every day, those tires would have probably been shot at about 10K and you'd be thinking much differently about how overinflating them has worked out

Try 50 in your next set and see how that works out. The manufacturer recommends a maximum of 51 and probably for a good reason

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

FiddlerJohn
Posts: 241
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Location: Bowie, Maryland

Re: Wheels, Rims, and Tires

Wed Jan 01, 2014 10:11 pm

JoeS wrote:SPARE TIRE

That's a coincidence. One day last week, I spent all day (and $8 for toll roads) in a auto parts "junk yard" looking for a SPARE TIRE for my favorite car.

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The SpaceSaver temporary spares T125/70D15 and T135/70D15 with 100 mm four lugs from some old Toyotas, Hondas, and VWs seems to fit the iMiEV.
Image Image

My OEM front tire is 145/65R15 with a 24.4" [Edit: 22.4" Thanks Don.] Overall Diameter. [Edit: Don also points out that chart revolutions per mile is wrong.]

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The SpaceSaver spare T125/70D15 has 22.1" Overall Diameter. The T135/70D15 spec is 570mm or 22.4".
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http://mcgrefer.com/sizeinfo/1357015

Now the interesting part:
At the junk yard I put the T135/70D15 on the front left and set out for home which was forty some GPS miles away. My RR was 9 more than the GPS so I felt safe. After hypermiling for 14 miles my RR was only 2 more than the GPS. I expected the difference to increase, but it was deceasing and fast. It was starting to get dark. At this rate I wouldn't make home. Or possibly get stuck in a toll tunnel.

Then the TMPI (tire monitor pressure sensor indicator) on the dash lit up. I pulled into a McDs and put the OEM wheel/tire back on. The T135/70D15 was warm to the touch but looked like it had good pressure. In a short distance the TMPI went out.

I got home with RR=1. The T135/70D15 pressure was 21 psi without a TMPI sender. That's why it was warm to the touch, but WHY WAS THE TMPI INDICATED? All four OEM tires with TMPI had 50 psi.
Last edited by FiddlerJohn on Thu Jan 02, 2014 7:52 pm, edited 1 time in total.

Barbagris
Posts: 237
Joined: Wed Feb 20, 2013 8:34 am
Location: Bilbao, Spain

Re: Wheels, Rims, and Tires

Thu Jan 02, 2014 1:41 am

FiddlerJohn wrote:...The T135/70D15 pressure was 21 psi without a TMPI sender. That's why it was warm to the touch, but WHY WAS THE TMPI INDICATED? All four OEM tires with TMPI had 50 psi.


Perhaps none of your tires has TMPI sender.

Perhaps the sensors are the ABS/ESP ones.

See "Indirect TPMS"
...learning...

alohart
Posts: 377
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Location: Honolulu, HI, and Uppsala, Sweden

Re: Wheels, Rims, and Tires

Thu Jan 02, 2014 4:04 pm

Would the i-MiEV be happy with a spare tire whose diameter is significantly different from the opposite tire? Wouldn't this potentially confuse the traction control?
Aloha,
Art
Honolulu: 2014 BMW i3 BEV (formerly 2012 i-MiEV SE)
Uppsala, Sweden: 2000 Honda Insight

Don
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Re: Wheels, Rims, and Tires

Thu Jan 02, 2014 6:14 pm

FiddlerJohn wrote:My OEM front tire is 145/65R15 with a 24.4" Overall Diameter.

Image
The chart doesn't jive with your 24.4 number, does it? The Revs/Mile is way off too

Now the interesting part:
At the junk yard I put the T135/70D15 on the front left and set out for home which was forty some GPS miles away. My RR was 9 more than the GPS so I felt safe. After hypermiling for 14 miles my RR was only 2 more than the GPS. I expected the difference to increase, but it was deceasing and fast. It was starting to get dark. At this rate I wouldn't make home. Or possibly get stuck in a toll tunnel.

Then the TMPI (tire monitor pressure sensor indicator) on the dash lit up. I pulled into a McDs and put the OEM wheel/tire back on. The T135/70D15 was warm to the touch but looked like it had good pressure. In a short distance the TMPI went out.

I got home with RR=1. The T135/70D15 pressure was 21 psi without a TMPI sender. That's why it was warm to the touch, but WHY WAS THE TMPI INDICATED? All four OEM tires with TMPI had 50 psi.
I *think* the iMiEV's computer did that to you, on purpose

It monitors the ABS signal from each of the 4 wheels, so it noticed your left front with the smaller tire was turning lots more revolutions per mile than it should be, so it *knew* that one was very low on air, which triggered the TMPS indicator on the dash. The RR meter also calculated in the extra drag on the car running with a nearly flat (so it thought from it's calculations of the Revs/Mile) so it knew you were not going to be getting the 'normal' miles/watt hour and it was alerting you to the fact that you weren't going to be getting the range you expected

These darned 'smart cars' are pretty tricky, aren't they?

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

FiddlerJohn
Posts: 241
Joined: Sat Jan 07, 2012 9:51 pm
Location: Bowie, Maryland

Re: Wheels, Rims, and Tires

Thu Jan 02, 2014 8:56 pm

Don. You're right. You point out three issues that I missed. Thank you.

Don wrote:... The chart doesn't jive with your 24.4 number, does it? The Revs/Mile is way off too ...

The chart says 22.4, but I typed 24.4". That's a typing error. Both Revs/Mile are way off. Yep. You're right again.

Now the most interesting part:
Don wrote:... It monitors the ABS signal from each of the 4 wheels, so it noticed your left front with the smaller tire was turning lots more revolutions per mile than it should be, so it *knew* that one was very low on air, which triggered the TMPS indicator on the dash. The RR meter also calculated in the extra drag on the car running with a nearly flat (so it thought from it's calculations of the Revs/Mile) so it knew you were not going to be getting the 'normal' miles/watt hour and it was alerting you to the fact that you weren't going to be getting the range you expected

These darned 'smart cars' are pretty tricky, aren't they?

Don

Yes! "Pretty tricky."

Does the i-MiEV have BOTH hardware TMPS AND "indirect TMPS?" That seems unnecessarily redundant. Barbagris also suggested "indirect TMPS." I guessing that the i-MiEV only has indirect TMPS.

My original point was -- these cheap 100mm, four lug, T135/70D15 Temporary Space Saver wheels and tires make a useable emergency spare tire for the i-Miev. AS IS! With the proper air pressure, the 22.4" diameter of the Temporary Space Saver is the same as the OEM tire.

Even better. Could these cheap Space Saver wheels be mounted with snow tires? I'm even considering mounting four new LRR tires on these wheels as backup spares.

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