Spare tire care reminder

[paris1]

Had occasion to use my space saver spare today (in order to drop a tire off for flat repair) and found that after 3 years of neglect hiding in its hole the pressure had dropped from the recommended 60 psi to 26! Wouldn't want to get caught out in the middle of nowhere with a flat/blowout on the way to grandma's house this holiday season with that kind of situation, so remember to check your spare pressure before heading out.

 

[inlinev]

Good call. I check mine about once a quarter. When I checked our brand new cx5 it was at 47 psi cold.

 

[yrwei52]

My spare tire dropped from 60 psi to 38 psi when I rotate the tires a couple of weeks ago. All four tires were dropped from 38 psi to 29 psi! I thought TPMS would give me a warning for these kind of substantial pressure drops but apparently it wouldn't!

 

[paris1]

My spare tire dropped from 60 psi to 38 psi when I rotate the tires a couple of weeks ago. All four tires were dropped from 38 psi to 29 psi! I thought TPMS would give me a warning for these kind of substantial pressure drops but apparently it wouldn't!

I run 30# pressure in my 17" tires (down from the recommended 34 psi in order to provide a little bit softer ride with H&R springs) and my TPMS tripped at 22.5 psi due to a slow leak in one tire. First time it's ever activated; at least I now know it works!

 

[MikeM.]

I run 30# pressure in my 17" tires (down from the recommended 34 psi in order to provide a little bit softer ride with H&R springs) and my TPMS tripped at 22.5 psi due to a slow leak in one tire. First time it's ever activated; at least I now know it works!

30# is really too low for normal pavement usage. You might consider raising the pressure to at least the recommended 34 psi. If the ride is too firm, maybe a spring rate closer to the OEM springs is in order. Tires perform a mostly different function compared to the suspension.

My experience with the TPMS on the CX-5 is that is alerts with a much smaller pressure differential than 7.5 lbs. I had a really slow leak in one tire and the TPMS alerted when the damaged tire fell 2-3 pounds below the 37 psi I normally run in the OEM Geolanders.

 

[craigo]

My spare tire dropped from 60 psi to 38 psi when I rotate the tires a couple of weeks ago. All four tires were dropped from 38 psi to 29 psi! I thought TPMS would give me a warning for these kind of substantial pressure drops but apparently it wouldn't!

This TPMS works by comparing rotation speeds among the tires using the ABS system. If they all drop evenly, you may not get a warning.

 

[madar]

I have a habit of checking mine twice a year, spring and fall. One of the very few things I don't like about this vehicle is that you can't put a full size spare back there.

 

[tibimakai]

I'm OK with the spare been so small, my subwoofer fits nicely this way.
I have to check the pressure though, because that pressure seals my sub enclosure.

 

[yrwei52]

This TPMS works by comparing rotation speeds among the tires using the ABS system. If they all drop evenly, you may not get a warning.

That makes sense! So there is no warning for low pressure on spare tire then. I heard many times on other cars the spare tire caused TPMS warning light. Those are having pressure sensor built into the tire valve stems.

 

[paris1]

That makes sense! So there is no warning for low pressure on spare tire then. I heard many times on other cars the spare tire caused TPMS warning light. Those are having pressure sensor built into the tire valve stems.

Not true. My TPMS light stayed on the whole time I was running around on the spare. Or are you talking about when the spare tire is low on pressure in the well??

 

[Kedis82ZE8]

A good reminder to do at least a yearly check on spare tire pressures. I'm guilty of discovering low pressure on a spare myself... fortunately not during a time of actual need.

 

[yrwei52]

That makes sense! So there is no warning for low pressure on spare tire then. I heard many times on other cars the spare tire caused TPMS warning light. Those are having pressure sensor built into the tire valve stems.

Not true. My TPMS light stayed on the whole time I was running around on the spare. Or are you talking about when the spare tire is low on pressure in the well??

Yeah, I did mean spare tire is low in the trunk well. There is no pressure sensor in the valve stem and there is no warning for low pressure if the tire is not on and turning.