12" Tires

[88FestivaLX]

OK, I see Tirerack has 145/12's in stock. The problem is I have 155's all around my car and just need to replace to 2 front ones (my steering rack is screwed and has screwed my tires up since I haven't been able to fix it). So whenever I put a new rack on it, I want to replace those tires (probably gonna be after my tax return, ha). Are there any other places that sell these?

[kumalaba]

ebay

[88FestivaLX]

Ha, I feel stupid

[David88]

Discount tire has them in stock here in Fort Wayne. My daughter just had tire issue on here car last week. She is in Aurora IL. The discount tire there had them on hand as well. I think they are aware few others have them. $$$

[kumalaba]

Ha, I feel stupid

pmd

[Pu241]

Fix the rack first!

PM Kartracer46, he had fix/repaired a number of racks.
Maybe setup an exchange with core or something.
Or you'll be buying more tires soon!

[pyrothehitman]

they still might fit the rim. My wife use to have 215's, 225's on her 18's. I think they are close enough to fit the rim, but I am not positive. I guess one of the main things to look for is clearance of the mechanics in the wheel well. But your going smaller, so that wont be an issue. I guess you could measure your rim and go from there.

[Pu241]

If he has OEM steelies the 145's are OEM the 155's are +1 (aka one size up)!

[Darlo]

better gas mileage with the 145s, if anyone cares.....haha

[GenevaDirt]

better gas mileage with the 145s, if anyone cares.....haha

no way....smaller diameter means higher rpms....the difference in size is not enough to matter on start off IMO, so overall I would say it would not matter except on a trip...giving you better mileage out of the 155's.

Besides....my 155's make my speedo spot on, never ran 145's to see the actual difference though.

[Pu241]

better gas mileage with the 145s, if anyone cares.....haha

Not necessarily, some 155's have a 44 psi cold inflation pressure, some only 35 psi.
If the 145's are 35 psi cold inflation pressure, then my bet would be on the 155's for max MPG.

[Darlo]

Not necessarily, some 155's have a 44 psi cold inflation pressure, some only 35 psi.
If the 145's are 35 psi cold inflation pressure, then my bet would be on the 155's for max MPG.

My 145's are 44psi, and my 155s' are only 35psi........ I get 48mpg average on the 145s and only 44mpg on the 155s.

Plus, the 145/155 number is the width......not the overall diameter (that is the second number)

Narrower tires are usually more efficient than wider ones. This is well documented.

[GenevaDirt]

My 145's are 44psi, and my 155s' are only 35psi........ I get 48mpg average on the 145s and only 44mpg on the 155s.

Plus, the 145/155 number is the width......not the overall diameter (that is the second number)

Narrower tires are usually more efficient than wider ones. This is well documented.

agreed the second number is a factor but if you are comparing 145/80's to 155/80's.... they are smaller in diameter. Thus higher rpms. It would really matter what type of driving you are doing with them....city or highway.



Tire Size Comparison

Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
145/80-12 4.6in 10.6in 21.1in 66.4in 954 0.0%
155/80-12 4.9in 10.9in 21.8in 68.4in 927 3.0%

[Pu241]

Just pointing out that some larger tires have higher rated pressures and will thus reduce rolling resistance so you might not see a drop. If you had 155's with 44psi max press I'll bet you'd see little difference, maybe even a slight increase due to the slightly taller tire.

[Pu241]

Looks like GD summed it up nicely!
and provided the rolling resistance, partly determined by tire inflation, is similar, you could get better MPG.