2017 CX-5 Spare Tire Mod for U.S.

bigtex

Member
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17 CX-5 GT 14 CX-5 GT (sold)
I hate the idea of having the incorrect diameter tire for the spare, especially when most other countries get a spare that has the correct diameter. Australia, Mexico, and most of Europe get a 185/80R17, which is still a temporary use spare, but it has an outside diameter of 28.7", which is exactly the same as the factory 225/55R19 (the 17" tires are 28.5" which is basically the same thing). In the US, we are given a tiny 145/90/16, which has an outside diameter of 26.3". A difference of 2.4". This small spare will go 68 more revolutions per mile than the stock tires when in use, which would be more important to AWD owners, but I think could also create problems for FWD if you have to put it on the front. Plus it is so damn skinny I don't trust how long this thing could actually hold up if you needed it to. I'm sure Mazda did this to save the 11.6 LB weight difference, but how much fuel can that save really?

You can't get the 185/70R17 tire available in other countries anywhere in the US. I tried a lot of places and you can't. But I did find a 165/90R17 from Tire Rack that also has the perfect diameter of 28.7". This picture shows the factory tire, the new spare from Tire Rack, and the original spare for comparison. Which spare would you rather use if you were in the middle of nowhere?

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Now the best part is that even though it is a much wider and larger diameter tire tire, it will fit in the spare storage area and still keep your floor perfectly flat. Here are pics of the original spare first, and the new, correct size spare second. Bose subwoofer will still fit perfectly.

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The only real "mod" you have to do, besides ordering a new spare wheel and tire, is to remove the foam blocks that Mazda installs in the floor board to make up the space created by giving us this incorrect sized tire. So you simply pull off these 2" thick foam pieces in the picture and the rear floor will rest perfectly on the new wider spare.

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One final pic of new spare vs original spare.

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Parts needed:
17" X 5.5" steel wheel from Med Center Mazda https://www.shopmazdaparts.com/oem-...re-9965025570/?c=aT01NDY1MTcwNSZyPWxheWVyXzE= $119.31
T165/90R17 Kumho T121 from Tire Rack https://www.tirerack.com/tires/tire...m=69R7KH&vehicleSearch=false&fromCompare1=yes $79.10
Weight of original spare and tire 24.4 LB. Weight of new spare and wheel 36.0 LB.

You can also use a true factory aluminum wheel and full size tire and it will fit diameter-wise, but the thickness will raise the floor level about 2.5".
 

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Very nice thought making the spare tire on CX-5 sensible. I was thinking the same thing getting a 185/80R17 spare used in Mexico but, like you did, found there's no sucih size available in the US. Your idea of using T165/90R17 116M replacing OE T145/90D16 106M as a spare is a good one, with the same outer diameter as the road tires. The only question I have now is how does Mazda fit in even wider 185/80R17 tire as a spare in Mexico and still keep the floor board flat? (uhm)

May be Chris_Top_Her should consider moving this thread into the How-To section, where this thread seems to belong, and doesn't get buried in this wheel and tire section.
 
I'm not sure how a 185 width tire would fit without raising the floor board at least 1/2" either Yrwei. In the US '17, there is some padding underneath the spare that may not be there in other countries is all I can come up with. Or maybe their foam that surrounds the spare is 20mm taller? But I do know that this setup with the 165 fits perfectly and the floor board is exactly flush and supported completely by the spare once you remove the foam blocks mentioned above.

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the spare is designed to be used for short distances only. at least we have a spare tire and kit to begin with unlike BMW's.
 
the spare is designed to be used for short distances only. at least we have a spare tire and kit to begin with unlike BMW's.

I'm sure that's fine for people who never leave the city, but make a few runs from San Antonio to Laredo or Dallas to Midland and you'll be glad you have a decent spare. I may need to go 150 miles or more to find a new tire or get a repair. But you are correct that the original smaller diameter spare should only be driven for very short distances. That's why I got rid of it and I have no problem driving 150 miles on this new one at 60 MPH and if I burn it up I will get another one for $80. At least I burned up the spare and not the differential and was able to get where I needed to be without waiting on a tow that might take hours to get to me and charge $4-5 per mile. Not to mention if it is late and everything is closed, I still have a chance of getting to my destination instead of getting a hotel, if I can find one.

The size difference in that tiny stock spare and the factory tires is just too great in my opinion. I would think more so if you have AWD. I put it on just to see what it looked like and it completely changes the way the car sits and surely has an impact on the suspension geometry. The car sits nice and level with the new spare. Worth it to me but probably not to most. And it's an easy swap and a relatively inexpensive improvement.
 
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Nice write up OP. And pictures do show stark contrast. So you had to buy wheel from Med Mazda then buy tire from tire rack. I'm assuming you had to go to local shop to get it mounted and balanced ? Did you check if tire rack sells the same size wheel so they do everything in one shot so all one has to do is just replace stock and take out the foam spacers.

Also, agree better for the spare tire to be as close to the same diameter of other wheels especially for AWD and the transfer case. Better to use your idea of modded spare especially if you're in a rural area and nowhere near a tire shop. Using original small spare would not be good for AWD system.

Just fyi, never use the spare in any of the front two wheels even with this mod spare. If you have a front flat. Proper way is to take good wheel from adjacent rear, and move to front, use spare on surrogate rear. It's a hassle like changing a flat twice but necessary for good control of front in case of emergency stops and emergency turns.
 
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This spare mod idea may gain traction afterall...(drinks) Thanks for taking the time to post and share the great pictures.

It is a ~$200 mod that will surely make some feel more at ease.


Also...Do not forget also that you have FREE ROADSIDE ASSISTANCE with your new Mazda...

from the Mazda USA site...

"The following Roadside Assistance Services are also covered during the New-Vehicle Limited Warranty period of 3 years/36,000 miles from the original warranty start date:

- Lock-out Assistance

- Gas Delivery

- Jump Starts

- Flat Tire Assistance

If you require immediate assistance, please contact Roadside Assistance directly at (800) 866-1998 or download the MyMazda application for iPhone* or AndroidTM** "
 
This spare mod idea may gain traction afterall...(drinks) Thanks for taking the time to post and share the great pictures.

It is a ~$200 mod that will surely make some feel more at ease.=QUOTE]


Mazdadude, I was wondering if you could check your spare and see what size it is when you have time? When I was looking at the specs, it shows 2016 AWD got a 155/90D18 which is actually about .3 larger diameter than stock tire height, but that's less than 1% difference, so basically the same thing. The 2016 FWD got the same tiny spare that the 2017 gets. And it looks like all '14 and '15' got the tiny spare. I wonder why they would just supply the proper diameter spare on '16 AWD vehicles?

From 2016 Owners Manual
Wheel size (in) 19 x 7 aluminum alloy
Tire size P225/55 R19 all-season tires
Temporary spare tire T145/90 D16 (FWD) / T155/90 D18(AWD)

Maybe all the AWD got this size and it is just not listed on all the owners manuals. That would make more sense as it seems more important for AWD owners to have the correct diameter.
 
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This spare mod idea may gain traction afterall...(drinks) Thanks for taking the time to post and share the great pictures.

It is a ~$200 mod that will surely make some feel more at ease.=QUOTE]


Mazdadude, I was wondering if you could check your spare and see what size it is when you have time? When I was looking at the specs, it shows 2016 AWD got a 155/90D18 which is actually about .3 larger diameter than stock tire height, but that's less than 1% difference, so basically the same thing. The 2016 FWD got the same tiny spare that the 2017 gets. And it looks like all '14 and '15' got the tiny spare. I wonder why they would just supply the proper diameter spare on '16 AWD vehicles?

From 2016 Owners Manual
Wheel size (in) 19 x 7 aluminum alloy
Tire size P225/55 R19 all-season tires
Temporary spare tire T145/90 D16 (FWD) / T155/90 D18(AWD)

Maybe all the AWD got this size and it is just not listed on all the owners manuals. That would make more sense as it seems more important for AWD owners to have the correct diameter.

I just looked and our 2016.5 TOURING AWD (17"wheels) has a T145/90/D16

Perhaps the GRANDTOURING AWD (19" wheels) comes with the larger spare?
 
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Nice write up OP. And pictures do show stark contrast. So you had to buy wheel from Med Mazda then buy tire from tire rack. I'm assuming you had to go to local shop to get it mounted and balanced ? Did you check if tire rack sells the same size wheel so they do everything in one shot so all one has to do is just replace stock and take out the foam spacers.

Also, agree better for the spare tire to be as close to the same diameter of other wheels especially for AWD and the transfer case. Better to use your idea of modded spare especially if you're in a rural area and nowhere near a tire shop. Using original small spare would not be good for AWD system.

Yes I had a local tire shop mount and balance the wheel and they only charged $10. I didn't check to see if Tire Rack had a wheel that would work but they might. Also, this same 17" steel wheel is used as the spare on the CX9 and CX7 (with a different size tire) so you may be able to find one from a salvage yard that has a wrecked CX7 or CX9.
 
I just looked and our 2016.5 TOURING AWD (17"wheels) has a T145/90/D16

Perhaps the GRANDTOURING AWD (19" wheels) comes with the larger spare?

That is strange. If you go to the Mazda USA website today and look at 2016 specs, it shows this 18" spare for Sport, Touring, and GT if they are AWD.

Here is spec for the Sport
Wheel size (in) 17 x 7 aluminum alloy
Tire size P225/65 R17 all season tires
Temporary spare tire T145/90 D16 (FWD) / T155/90 D18(AWD)
 
The spare should just be the same size as the other tires just like they used to do in the 90s.
 
The spare should just be the same size as the other tires just like they used to do in the 90s.

Exactly, or they should at least make the spare storage area compatible with a full size spare wheel/tire for people who wanted to add that as an option. For those that wanted to get .01 more MPG's, they could opt for the donut spare or no spare at all to save some pounds.
 
just FYI, the CX-7 had two types of spares also,

the AWD CX-7 got the 18x4 rims T155-90D18 (28.9" diameter)

https://www.ebay.com (commissions earned)





and the FWD CX-7 got smaller 17x5-1/2 rims (sorry don't know the tire size, eBay listing didn't have this info) but I bet it's like the CX-5 FWD (26.3" overall wheel diameter) picture below shows tons of empty space like it is a 26.3" diameter wheel

https://www.ebay.com (commissions earned)




I might be wrong, but I think OP should have gotten the 18" rims with T155-90D18 tires.

The 17" rims are suppose to be compact but I think OP made up the difference with thinner tire width 165mm instead of 185mm and taller sidewall tires which may or may not have been designed for that at highway speeds or quick turns....... I'm not an expert , so OP might be just fine but just doing a search showed that the CX-7 also had two types of spare tires. One for AWD (18" rims) and one for FWD (17" rims) models.
 
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I might be wrong, but I think OP should have gotten the 18" rims with T155-90D18 tires.

The 17" rims are suppose to be compact but I think OP made up the difference with thinner tire width 165mm instead of 185mm and taller sidewall tires which may or may not have been designed for that at highway speeds or quick turns....... I'm not an expert , so OP might be just fine but just doing a search showed that the CX-7 also had two types of spare tires. One for AWD (18" rims) and one for FWD (17" rims) models.

You could use either the 17" or the 18" wheel. I liked the 17" better because it is wider than the 18" (5.5" vs 4") and allowed either a 165 or 185 width as opposed to the 155 width limit on the 18" wheels.
As long as you keep the overall diameter close to 28.7", either one will work much better than the stock spare which is only 26.3".

Both of those ebay listings look like the tires are about 10 years old, so I wouldn't want those for my spare, but if you could get the wheels only for a reasonable price and put a new 165/90R17 or 155/90R18 on them, either would work as a great alternative for the factory spare.

If you purchase the new wheel from Med Center Mazda, the shipping is free. So if you get a used wheel and the freight knocks the price up to near $100, I would just get the new wheel if it was me.
 
You could use either the 17" or the 18" wheel. I liked the 17" better because it is wider than the 18" (5.5" vs 4") and allowed either a 165 or 185 width as opposed to the 155 width limit on the 18" wheels.
As long as you keep the overall diameter close to 28.7", either one will work much better than the stock spare which is only 26.3".

Both of those ebay listings look like the tires are about 10 years old, so I wouldn't want those for my spare, but if you could get the wheels only for a reasonable price and put a new 165/90R17 or 155/90R18 on them, either would work as a great alternative for the factory spare.

If you purchase the new wheel from Med Center Mazda, the shipping is free. So if you get a used wheel and the freight knocks the price up to near $100, I would just get the new wheel if it was me.

Ah, good explanation, thanks for write up and good idea thanks for sharing. I'll move forward with this mod. If anything having two spares will also ease rotation of tires i like to do the "X" pattern rotation so with two spare tires it'll speed up the process somewhat.
 
That is strange. If you go to the Mazda USA website today and look at 2016 specs, it shows this 18" spare for Sport, Touring, and GT if they are AWD.

Here is spec for the Sport
Wheel size (in) 17 x 7 aluminum alloy
Tire size P225/65 R17 all season tires
Temporary spare tire T145/90 D16 (FWD) / T155/90 D18(AWD)
I had the same confusion like you when I was looking for some alternatives replacing smaller-diameter temporary spare too on my 2016 CX-5 AWD. I thought Mazda made a mistake from factory putting wrong spare for FWD into my AWD CX-5 which was special-ordered and picked it up immediately once it got trucked into our dealer's lot. But as stated in our owner's manual, later I verified all CX-5's, FWD and AWD, are getting T145/90D16 106M smaller-diameter temporary spare with 60 psi air pressure. I was then looking for Mexician alternative with 185/80R17 95M regular tire and 36 psi air pressure, but giving up after I found that size of tire isn't available in the US.

BTW, the larger-diameter temporary spare - T155/90 D18 which is supposed to come with US CX-5 AWD and specified at Mazda USA website is actually having the correct overall diameter at 28.5" as our road tires. This's the spare we should get for AWD owners but didn't. It seems Mazda North American Operations don't care much about burning out AWD system while using much smaller spare tire! This's the first sign I found that Mazda or MNAO is cutting corners at every possible way and since then started finding more ⋯
 
Both of those ebay listings look like the tires are about 10 years old, so I wouldn't want those for my spare
Great point! Tire ages as the years go by even we never use it. Many tire manufactures offer warranty only up to 6 years now. Yeah 10-year-old spare could be dangerous to use!
 
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