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2011 Forrester 2.5x Prem.
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Discussion Starter · #1 ·
I have a set of 215/55-17" blizzaks I have been thinking about mounting up on my 2011 Forester. The oem size is 225/50-17 the difference according to Tire size calculator is:



Think I'd have any warning lights or other weird issues if I ran these? Everything I've read leans toward up to 1/2" difference in diameter being acceptable, thoughts?

Tia!
 

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2006 2006 & 2010 Forester automatic
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I'm going to put 215/60/17 on the '10 when it needs tires again...so the speedometer will quit being 1.5mph off.

Did they change the OEM size '10 to '11? '10 is 225/55/17.
 

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2011 Forrester 2.5x Prem.
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Discussion Starter · #3 ·
No, they didn't change it. Tirerack.com claimed the size was a 215/55-17 but cars101.com and my own vehicle confirmed it is a 225/55/17

So, based on that the difference is:

Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
225/55-17 4.9in 13.4in 26.7in 84.0in 754 0.0%
215/55-17 4.7in 13.2in 26.3in 82.7in 767 -1.6%

Thoughts on if that would screw up things or throw off the car?
 

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2015 Highlander AWD XLE 6AT
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The Blizzaks are slightly smaller than OEM, but, as long as you mount four of 'em, then the drivetrain won't know the difference except for the speedo and odo both reading a bit high.

What's the service description for the Blizzaks? Should be a alpha-numeric combination like "95H".

Rehards,
Jim / crewzer
 

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2011 Forester 5 Speed Manual
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1,613 Posts
hmmm interesting,
my 2011 came with 225 55 17
I bought a used set from a 2011 forester owner he got from tire rack that are 16" wheels with 205 65 16 blizzaks
 

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2015 Highlander AWD XLE 6AT
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I bought a used set from a 2011 forester owner he got from tire rack that are 16" wheels with 205 65 16 blizzaks
I've never understood that size recommendation from Tire Rack. All 2009-13 Foresters in the U.S. market came with one of two tire sizes:

Base model non-turbo: 215/65R16
All others: 225/55R17

These tires are nominally very close to being the same size (i.e., diameter, circumference, or revs/mile). Both our '09 and '12 Foresters w/ Premium trim were OEM fitted with 225/55R17 tires. Our winter tires and our full-size spare are 215/65R16.

HTH,
Jim / crewzer
 

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... go figure ... they work well on highway and in the snow and I haven't noticed a huge difference in gas mileage.
 

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2011 Touring 4EAT
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I've never understood that size recommendation from Tire Rack. All 2009-13 Foresters in the U.S. market came with one of two tire sizes:

Base model non-turbo: 215/65R16
All others: 225/55R17

These tires are nominally very close to being the same size (i.e., diameter, circumference, or revs/mile). Both our '09 and '12 Foresters w/ Premium trim were OEM fitted with 225/55R17 tires. Our winter tires and our full-size spare are 215/65R16.

HTH,
Jim / crewzer
It does make me wonder if Subaru makes any changes to the speedometer/odometer for the two different models. The label on the doorpost reflects the correct tire size but I wouldn't be surprised if that was the only difference.

Interestingly, he Subaru dealer recommended and sold me 225-60-16 snows which are even closer in circumference to the 225-55-17's it came with. The argument was that it is best to stay with the recommended width if possible. However, as mentioned above I do wonder if the only actual difference is the wheels and tires.
 

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2015 Highlander AWD XLE 6AT
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It does make me wonder if Subaru makes any changes to the speedometer/odometer for the two different models.
In terms of the OEM tires on the 2012 Forester, there's vitually no difference in circumference. Specifically, the Yokohama 225/55R17 tires are spec'd at 772 revs/mile, and the Bridgestone 215/65R16's are spec'd at 771 revs/mile.

Allowing for manufacturing tolerances, these specs would allow for universal speedo/odo calibration.

HTH,
Jim/crewzer

Correction: Yoko G95A tires in size 225/55R17 are spec'd at 775 rev's/mile, not 772. :icon_redface: I still think their "close enough".
 

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In terms of the OEM tires on the 2012 Forester, there's vitually no difference in circumference. Specifically, the Yokohama 225/55R17 tires are spec'd at 772 revs/mile, and the Bridgestone 215/65R16's are spec'd at 771 revs/mile.

Allowing for manufacturing tolerances, these specs would allow for universal speedo/odo calibration.

HTH,
Jim/crewzer
FWIW, the Tire Calculator I used shows a 0.8" difference in circumference between these two sizes.

225/55-17 215/65-16 Difference
Diameter inches (mm) 26.74 (679.3) 27 (685.9) 0.26 (6.6) 1%
Width inches (mm) 8.86 (225) 8.46 (215) -0.39 (-10) -4.4%
Circum. inches (mm) 84.02 (2134.08) 84.84 (2154.82) 0.82 (20.73) 1%
Sidewall Height inches (mm) 4.87 (123.75) 5.5 (139.75) 0.63 (16) 12.9%
Revolutions per mile (km) 754.11 (468.58) 746.86 (464.08) -7.26 (-4.51) -1

225/55-R17 vs 215/65-R16 Tire Comparison - Tire Size Calculator
 

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2015 Highlander AWD XLE 6AT
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Correction above: Yoko G95A tires in size 225/55R17 are spec'd at 775 rev's/mile, not 772. :icon_redface:

The problem with these calulators is that their results are purely a math exercise. Rather than being exact, tire sizes are nominal, so, for any given industry standard tire size, the actual dimensions will vary a bit.

Actual dimensions can be checked on tire manufacturers' websites and at Tire Rack. For example, when I quickly looked at 24 of the 55 models of 215/65R16 tires on Tire Rack's site, I found diameter specs ranging from 26.7" to 27.1", and revs/mile specs ranging from 783 (relatively small) to 766 (relatively large).

For me, the "revs per mile" spec is a more accurate indicator of operational tire size, especially when considering details like speedometer- or odometer error.

HTH,
Jim / crewzer
 

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Thanks for some great info. My commute to work is 28.1 or 28.2 depending on whether I have my Snows or All Seasons. This should make a good case for using one of them as a spare in place of the Temporary spare. (Sorry for the off topic comment)
 
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