Spare tire that fits!

[Rick Reagan]

Thanks for the pictures. Is the outside diameter way different? I know the tire pressure monitoring is done by looking at the rotation speed between the tires, not that it matters it the car displays a 'low tire' warning while running a spare. I am thinking about the situation where you are running it on the front and how the differential would handle it if there was a large difference in the diameter. A friend had a bent wheel on the back of his truck and ran a car tire (somehow the bolt pattern was the same) and drove it 20 miles to town. The 'diff' was literally smoking when he got there and jacked it up. Granted it was probably a 20% difference in rotation speed but it did get me to start wondering???

--> Good question: the dealer did not drive it, just verified it fit and rotated without hitting the brake calipers.

 

[bpratt]

I agree it would not be a good idea to drive very far with different size tires on the front of the car. If a front tire get damaged, replace one of the rear tires with the spare and use the tire removed from the rear to replace the damaged tire on the front.

 

[peekay]

I agree it would not be a good idea to drive very far with different size tires on the front of the car. If a front tire get damaged, replace one of the rear tires with the spare and use the tire removed from the rear to replace the damaged tire on the front.

That is a good idea. But I'm not sure if one scissor jack can handle propping up an entire side of the car. We might need two jacks, or maybe a rock or piece of wood. Haha, this is snowballing.

With my spare, it appears that, when mounted, the diameter is comparable to the stock tire. When unmounted, it actually appears to be slightly bigger than the stock tire, but it compresses more than the stock tire when under load.

 

[Steven B]

That is a good idea. But I'm not sure if one scissor jack can handle propping up an entire side of the car. We might need two jacks, or maybe a rock or piece of wood. Haha, this is snowballing.

With my spare, it appears that, when mounted, the diameter is comparable to the stock tire. When unmounted, it actually appears to be slightly bigger than the stock tire, but it compresses more than the stock tire when under load.

Order of operation:
1) Jack up rear, remove full size tire and install spare
2) Lower rear, move jack to front and jack up front
3) Replace flattened tire with full size removed from rear
4) Lower jack

 

[ZedFez]

I bought a flat repair kit, one of those tire plug kits but I still felt uncomfortable on long trips with no spare tire. So I started to research to see what donut spare tires may fit.

The various Accord models have donut spares but the problem is that they are only 15 or 16 inch wheels and the Clarity appears to have extraordinary large brake calipers and discs. By my eyeball test, it looked like it would be a really tight fit even with a 16 inch spare. The last thing I needed is a donut spare that doesn't fit, so I looked elsewhere

I discovered that many Infinities and Nissans also share the same bolt pattern as the Clarity. More importantly, for some of the Nissan 370Z and Infiniti G37 models, they come with 17 inch donut spares. One bonus is that some of them have alloy donut rims rather than the usual steel donut rims. This will save a little weight.

Another benefit is that these donuts are fairly large. They are basically the same size as our standard tires. Normally, I would be fine with a small donut, to save on space, but given the electric motors on the Clarity, I wasn't sure if sustained differences in rotational speed will be bad for the car.

So here is a G37 donut spare installed. I bought it on eBay for $97, plus an additional 15% off coupon that ebay periodically sends out. The seller, mullinsautoparts, was fantastic and shipped the spare immediately. It was also in new condition.

The spare tire was listed as:
2007 2008 2009 07 08 09 Infiniti G35 EX35 Sedan 17x4" Compact Spare WheelView attachment 1518 View attachment 1518

Just located one of these from a junkyard for $45 US plus tax. Thanks for the tip

 

[ZedFez]

Quoting PEEKAY here... With a question at bottom —

here is a G37 donut spare installed. I bought it on eBay for $97, plus an additional 15% off coupon that ebay periodically sends out. The seller, mullinsautoparts, was fantastic and shipped the spare immediately. It was also in new condition.

The spare tire was listed as:
2007 2008 2009 07 08 09 Infiniti G35 EX35 Sedan 17x4" Compact Spare WheelView attachment 1518 View attachment 1518 [/QUOTE]
Will you please post and/or confirm the size of the spare you got? In your trunk photos the spare looks smaller than how it sits in my trunk. The size of the spare I got is: T165/80R 17 104M. It’s a Bridgestone. The tread is different than yours but the wheel it sits on looks identical to yours. Thanks! After a 2nd look... more similar than different in size I suppose.

 

[peekay]

Quoting PEEKAY here... With a question at bottom —

here is a G37 donut spare installed. I bought it on eBay for $97, plus an additional 15% off coupon that ebay periodically sends out. The seller, mullinsautoparts, was fantastic and shipped the spare immediately. It was also in new condition.

The spare tire was listed as:
2007 2008 2009 07 08 09 Infiniti G35 EX35 Sedan 17x4" Compact Spare WheelView attachment 1518 View attachment 1518

Will you please post and/or confirm the size of the spare you got? In your trunk photos the spare looks smaller than how it sits in my trunk. The size of the spare I got is: T165/80R 17 104M. It’s a Bridgestone. The tread is different than yours but the wheel it sits on looks identical to yours. Thanks! After a 2nd look... more similar than different in size I suppose.[/QUOTE]
Mine is 145/80/17. Yours is a bit bigger. Have you tried installing it yet? When mine is actually mounted on the car, it looks pretty close in size to the stock tire. I'd imagine yours might even be a little bigger.

 

[ZedFez]

If I understand how tires work, the 2nd number is a ratio related to the first number. So my tire distance from the rim to the outside edge is 80% of the tread surface width. (If I’m wrong, please correct me, I don’t know much about tires). If that assessment is correct 80% of 165mm comes to 132mm or 5.2 inches of tire to the road from the rim. When I do the same with yours, 116mm or 4.57 inches. Looks like I need to get that thing on the car to see how it fits, or return it. Good thing I got it local. —Also— I do not know what the final number of 104m means for the tire size. Need to look that one up.

 

[peekay]

If I understand how tires work, the 2nd number is a ratio related to the first number. So my tire distance from the rim to the outside edge is 80% of the tread surface width. (If I’m wrong, please correct me, I don’t know much about tires). If that assessment is correct 80% of 165mm comes to 132mm or 5.2 inches of tire to the road from the rim. When I do the same with yours, 116mm or 4.57 inches. Looks like I need to get that thing on the car to see how it fits, or return it. Good thing I got it local. —Also— I do not know what the final number of 104m means for the tire size. Need to look that one up.

Yes, that's basically right. The only other number that impacts the radius or the diameter of the tire is the 17, which stands for the rim size.

 

[insightman]

I've been following this dialogue closely. Would a valid test of a 17" donut be to

1. Measure the distance from the road to the top of the front wheel arch
2. Replace the front OEM with the donut
3. Drive the car back and forth to unload the suspension after jacking for the wheel change
4. Re-measure the distance to the top of the front wheel arch

If the distance is the same, then the weight-compressed diameter of the donut is the same as the OEM, right?

 

[ZedFez]

I've been following this dialogue closely. Would a valid test of a 17" donut be to

1. Measure the distance from the road to the top of the front wheel arch
2. Replace the front OEM with the donut
3. Drive the car back and forth to unload the suspension after jacking for the wheel change
4. Re-measure the distance to the top of the front wheel arch

If the distance is the same, then the weight-compressed diameter of the donut is the same as the OEM, right?

Funny insight man... after doing all that math, realized all I needed to do was grab a ruler and measure the radius of both the Clarity wheel, and the spare I got. I just did it and the spare wheel is 1/2 inch longer from dead center to the outer edge of tire. 1/2 extra inch should fit just fine in the wheel-well, just got to try it to be sure. Gut feeling is that making sure the spare is ONLY on the rear, since it is larger, it should be fine. Was going to try to fit it on there tomorrow, but my hydraulic jack is 40 miles away, and I’m not using a scissor jack for fun.

 

[peekay]

I've been following this dialogue closely. Would a valid test of a 17" donut be to

1. Measure the distance from the road to the top of the front wheel arch
2. Replace the front OEM with the donut
3. Drive the car back and forth to unload the suspension after jacking for the wheel change
4. Re-measure the distance to the top of the front wheel arch

If the distance is the same, then the weight-compressed diameter of the donut is the same as the OEM, right?

If you guys are really interested, I can put the donut back on and try driving around town with it to see if it triggers the tire pressure sensor light. My sense is if it doesn't trigger the light, then the size is close enough to not harm the car.

 

[Everbody]

I want a spare! Will keep it at the house when driving in town, throw it in the trunk on long trips. AAA will tow it home where I can use the big boy jack.

Sent from my SM-T580 using Inside EVs mobile app

 

[Emanuel Green]

Well I'll be.... Didn't know that was possible. That will be one fewer expensive repair events - presumably no battery involved, and easier recalibration after tire rotation or replacement . I wonder how low the tire pressure has to be to trigger the warning. My old Odyssey would give an error at about 28 psi.

I believe it can tell the diameter of the tire based on how many rotations it goes through compared to the other tires. A flat tire will have a smaller diameter, so it will be rotating faster than a full one when going the same speed. So the car's computer can tell if one tire is smaller than the others, and this triggers the low pressure warning.

 

[bpratt]

I just purchased a 145/80/17 G37 Donut spare on Ebay. I have a small hydraulic jack that works but does anyone know what size the lug nuts are. A 3/4 inch and a 19 mm socket both seem a little loose. It might be 18 mm but I don't have one to try.

 

[insightman]

I just purchased a 145/80/17 G37 Donut spare on Ebay. I have a small hydraulic jack that works but does anyone know what size the lug nuts are. A 3/4 inch and a 19 mm socket both seem a little loose. It might be 18 mm but I don't have one to try.

I've been using 19mm sockets on my Honda lugnuts for decades. However, just to be sure, I tried an 18mm socket on our Clarity and it's too small.

 

[neal adkins]

I threw in a torque wrench (1/2 in drive) as my lug wrench. The 19mm socket seemed to fit ok. I bought a scissor jack at walmart for 25$ plus tax. I went with the same infinity q35 17in spare shown in this thread. Got a coupon for 25$ off too on ebay.

 

[insightman]

Has anyone created a way to secure the spare in the trunk to prevent it from becoming a projectile in a tumultuous accident?

 

[Pushmi-Pullyu]

If you guys are really interested, I can put the donut back on and try driving around town with it to see if it triggers the tire pressure sensor light. My sense is if it doesn't trigger the light, then the size is close enough to not harm the car.

Not that I own a Clarity, but just as someone watching the group effort here; our InsideEVs community trying to solve the problem of Honda not selling a spare for the Clarity...

I was hoping that someone would at least try driving on the spare for a few miles at low to moderate speed. If I was thinking of buying such a spare, I'd want to make sure that someone had tested it by working the steering back and forth to the wheel locks, to make sure the spare doesn't rub on anything; and also pumping the brakes, to make sure that no part of the rim interferes with brake action.

But thanks very much, Peekay, for your efforts here! The last time I looked at discussion of this subject, nobody had even found a spare that would fit the Clarity. What you've done here is a real service to the EV community, so take a bow!

 

[Steven B]

Not that I own a Clarity, but just as someone watching the group effort here; our InsideEVs community trying to solve the problem of Honda not selling a spare for the Clarity...

I was hoping that someone would at least try driving on the spare for a few miles at low to moderate speed. If I was thinking of buying such a spare, I'd want to make sure that someone had tested it by working the steering back and forth to the wheel locks, to make sure the spare doesn't rub on anything; and also pumping the brakes, to make sure that no part of the rim interferes with brake action.

But thanks very much, Peekay, for your efforts here! The last time I looked at discussion of this subject, nobody had even found a spare that would fit the Clarity. What you've done here is a real service to the EV community, so take a bow!

I thought the general consensus for installing spare donuts (on non-awd vehicles) has always been NOT to install them at locations connected to the propulsion system, therefore, these oddball spares that are being considered would not be installed at either of the front wheel locations and subjected to steering loads or interferences.