John*K

What pressure is the spare tire supposed to be set at? I got a flat, and need to make sure that it is set correctly. Ugh.

fuzzy02CLS

iTrader: (2)

Set it to what it says on the tire. It should say it I don't remember what it was.

juniorbean

iTrader: (5)

What he said. I think it also mentions it in the manual.

John*K

That's the thing -- it says 60 psi, but that seems like a lot for the spare.

CO-CL-S

Sounds right to me. It's a small/narrow tire that needs high air pressure..

Scrib

It should tell you right on the inside of the driver's door what it should be set at. Look for it with the other tire pressures that are listed...

juniorbean

iTrader: (5)

Sounds about right to me too. When I needed to install my spare I think I was running it at 58 PSI

spdy0001

smaller tires = more psi
larger tires = less psi

Look at a road bicycle the tires are about an inch in width and some of them run 75 PSI

Bobbydoedoe

i was bored and i actually look that up for u. The manuel says 60psi while the other non temp tire are suppose to be 32psi

Chopsie

You still have spare tire, thats more weight in the beast.

Ant7701

60psi

mattg

it says 60 because it needs to be set @ 60psi. it's not a misprint.

aciurczak

It also loses pressure more quickly than you'd think. I check it every few months in both my cars, and it is usually down to 45 psi or so, though I set it to 60 every time.

John*K

Thanks for the help, guys. Always better to be safe and ask and learn. Thanks for the tip, too, acuirczak. That is good to know.

shmookles

What does oen do if they have 18" rims and you get a flat? My aftermarket tires are 215/40/18 but my stock spare tire is a little bigger. Do i need to get a new spare or can I use this one for a short time to get to the garage?

spdy0001

The diffrence is so small that you won't have a problem using your spare for a short time till you can fix your other tire

Shawn S

I agree, and I also suggest NOT going with 215/40/18’s when you replace the tires.
Go with 225/40 or 235/40 for a closer diameter to stock.

Shawn S

shmookles

Shawn,
Thanks for the input. Yeh I'm not too thrilled withthe 215s, but I got such a good deal on my RH C5's wit hthese tires and it seemed liek such a shame to throw them away. So I figured I would use them for sometime before gettin new wheels...

My one question is why would the 215 be any different then 225 or 235, isn't the difference simply in width not in height? I thought as long as they were 40 it was the same thing?

Shawn S

The “40” means that the sidewall is 40 PERCENT of the tire WIDTH.
Wider tire means higher sidewall means larger diameter.
You could also go to a 215/45 for the same effect.

shmookles

damnit, that means I misunderstood that whole 40 thing. Goddamnit!!! Do you think I need to switch my tires soon or is it safe to use these up and then switch to 225 or 235?

Shawn S

I would use them up.
It’s safe, but just beware that your speedometer and odometer are off by a bit.
Not sure if it’s high or low.

Scrib

http://www.miata.net/garage/tirecalc.html