Winter tire pressures vs spare pressure

[Cartman]

My winter set up is the same as the factory spare (185/60/15 Bstone Blizzaks). Sticker on driver side says 44psi for spare, but 39/36 for stock summmers. What pressures should I go with?

 

[Jerickson88]

My winter set up is the same as the factory spare (185/60/15 Bstone Blizzaks). Sticker on driver side says 44psi for spare, but 39/36 for stock summmers. What pressures should I go with?

Check the pressure recommendation for that size for the fiesta that runs 15” wheels. Or you could just run 35psi and probably not notice any difference?

 

[alexrex20]

I'd probably run them at 32psi. You aren't gonna be doing any hard cornering in the snow, right?

 

[Speedboosted]

I'd imagine he's worried about it feeling extra floaty and mushy with the tall sidewalls. Plus seeing the difference in pressure rec. between the factory tires and spare, it raises a decent question. I would start with 41/39 and see how it feels.

 

[JDG]

The spare pressure is set for 44 PSIG because it is a low speed tire intended to be used on a temporary basis. I believe the max speed allowed on it is 50MPH or so due to less layers of rubber and little to no steel belting.

I would run your winter tires at 40PSIG on the street to start. This is what I run mine at and have had good luck with both wet, snow, and dry performance. If going fast in the dirt, you'll want to run them close to the max pressure (~ 50 PSIG) as to prevent de-beading.

 

[kenweise]

I am running mine at 32psi, mainly for comfort. They are not a handling tire.

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[theblue]

Tire pressures should be set based around a number of factors such as the weight of the car, temperature of the tire, desired handling bias and driving style (to list a few). Most people should just follow what's on the drivers door while more advanced drivers may deviate the bias based on how the temperatures and wear look along with feel. As already said, ignore the spare tire, that's a special case.

The way I set up my street cars is to start a the recommended numbers which you set at cold (before driving). Then I bring them up to temp and feel for oversteer / understeer and adjust front to rear ratio to get a neutral car. I keep and eye on wear (as a have been known to drive pretty hard on the street) and move everything up or down a little if they are wearing center vs. shoulders or overheating.

 

[jpnovrnghtprts]

Zero complaints running factory PSI on general artimax on 15s

 

[Cartman]

All, thanks for all the feedback. I am trying 40 front 38 rear and it seems to be better at highway speeds than summer tire pressures.

 

[FiSTerMr]

The spare pressure is set for 44 PSIG because it is a low speed tire intended to be used on a temporary basis. I believe the max speed allowed on it is 50MPH or so due to less layers of rubber and little to no steel belting.

Ordinarily yes, space saver spares are built differently. But I think the full size spare is a standard steel belted radial.

I believe the full size spare is spec'ed for 44psi to compensate for the taller sidewall. The extra psi brings it up to the 17" 40 series sidewall flexing properties.

I would run your winter tires at 40PSIG on the street to start. This is what I run mine at and have had good luck with both wet, snow, and dry performance. If going fast in the dirt, you'll want to run them close to the max pressure (~ 50 PSIG) as to prevent de-beading.

I just installed my steelie set up and immediately hated how it felt; I jacked up the fronts to 45 and rears to 42 (5psi over what I normally run with the stockers), and am much happier now.

I know this somewhat defeats the purpose of taller sidewall for winter, but I felt like 75% of the car's charm was being lost. I will deflate accordingly for any snow/rain storms. As I live in a quickly plowed area (NYC, Long Island, NJ), dry performance is important to me.

 

[M-Sport fan]

Ordinarily yes, space saver spares are built differently. But I think the full size spare is a standard steel belted radial.

That's what I thought as well, but then I noticed the 50 MPH MAX SPEED warning sticker on the wheel, applied at the factory, so I am wondering if JDG may be correct about there being less plies in the sidewalls of the full size spare tire as it is delivered.

Unless Ford puts that sticker on there just to lessen the chances of anything going south due to the height differences between the 205/40-17 mounted setup, and the 185/60-15 spare, especially taking the ESC/TC computer programs into account?