Just got the tires in from tirerack for the wife's car.

(RE050a - pole positions)

255/40-18 and 275/40-18

I expected the 275's to be wider, but they are the same width as the 255's.

I layed them down on their sides next to each other and they are the same width, exactly and the tread is the same width. Only different is that the 275/40 is a bit taller overall.

Just not what I expected... can anyone explain why this is?

 

I somewhat felt the same way. The 275s are of course wider, but the difference is just not that severe. The 255s are decently wide in themselves.

 

its only 20mm difference, and some brands have different specs and ways to measure. I know my rears are wider than my fronts, its easy to see.

 

yeah i think it's just cause the 20mm is not too much so maybe it looks similar. it makes sense that the 275 is wider because of the taller sidewall

 

Just went to TireRack's site and looked up that tire. Their specs list the tread width of the 255/40/18 as 9.1" and the 275/40/18 as 10". Don't know what you are seeing.

Lou

 

I imaging the difference with be more noticeable once the tires are mounted and on the car

that is on different width wheels

 

So The overall tire width varies (.2" for every .5" width change) with wheel width change, but the tread width remains constant.

Lou

 

that would hold true if the tires were from different manufacturers. The tires are all from the same manufacturer and should have different tread widths.

a 275 bridgestone should be wider then a 255 bridgestone. 20mm is nearly a inch and should be noticable.


would have to see pics of the sidewall and the comparisions.

 

275 mm tires are 20 mm wider that 255 mm tires. That’s a fact.

 

 

You're not looking at the pole positions, you're looking at regular re050a's

Pole positions are listed as such:
255/40/18 section width = 10.2", tread width = 9.3"
275/40/18 section width = 10.7", tread width = 9.3" (wtf?)

So they are even listed as having the same width tread, which is what I am seeing. I guess the 255 is wide and the 275 is narrow? They play with the tread design to try and make one look wider than the other, but the tread width is almost identical.

The casing on the 275 is not even 10mm wider than the 255. I'll post pics soon. I can't tell which is which without looking at the "size" on the tire

I am sure they'll be fine, I just thought a 275 would be 20mm wider than a 255, but in reality, they are only 8mm wider (section width) and the tread might be a whole 2mm wider. Just weird...

 

I wish that were true... apparently it's not...

 

OK, OK....

Pic ho's


Which is the 275?


It's mostly just taller, not much wider:


Not much different. Doesn't look 20mm wider:


Let's take a hard look:


OK; four nickels and a dime (is that 20mm?)


Well, let's just check... Where's my other 12mm I paid for?


The sidewalls; haven't touched that ruler in 10 years :

 

LOL...thats awesome

Just install and enjoy them....it's still 8mm wider

 

The one one the right is the 275.

In the other pics, you're lining them up dead center and measuring the difference on one side, of course that will only be 10mm (which is only .4")!!!!!

I still don't see what you're questioning. They look right. There's also the distinct possibility that the difference in wheel widths is making them "look" equal based on the stretch on the sidewalls.

 

On the measurement pics, they are both laying flat on my patio table, nit lined up center-to-center.

Still only 8mm different, but I paid for 20mm...

 

Yeah, wife says I must be tweakin!

She'll enjoy them. She's presently running OEM 225/245 (re040) on her after-market wheels so this'll be a nice step up. At least handling should be well-balanced!

Not too worried about clearance either. We'll post pics when it's done.

 

+1

 

Well, They're not mounted yet...

I'll post back when they're on the wheels and on the car...

 

of course the 275 is wider. the majority fitment for tires here on the boards are 245 front and 275 rear. that is why the 275 look significantly wider when compared to a 245.