Tire size question

[turboj91]

Time for another set of tires (167K miles). This time I will go with the 185/65/14 B-381 Bridgestones. These are ever so slightly taller than the oe 175's. Has anyone made the change and are there are any issues (spedo differences?) that would make this tire purchase a "no-no"?

Thanks in advance
Jim

[prius2go]

Sorry all of this for gen 2 5 door hatch

I've gone slightly up a size both when I tried 17" 205 50 (which was very good for road holding - the car felt much flatter) and now back to Celica 16" 205 55
In UK OEM is 16" 195 55
The speedo will read slightly slow but as it's designed to read slightly fast, then you should be ok.
Your apparant mpg will drop too as it thinks you're travelling less miles than you are.
Page 2 of this site has some calculators
Car Bibles : The Wheel and Tyre Bible Page 1 of 2

Offset is critical - if changing wheels work out how much extra the wider tyres stick out
OEM wheels have an offset of 45 (ET45)
Celica are ET38
The lower the offset the further apart the wheels will be
Common 17" are ET35 which with 205 is just too much for the front wheel arches
PCD is 5x100 and watch out for bore adapter rings and domed nuts etc

[zonie911]

Originally Posted by turboj91

Time for another set of tires (167K miles). This time I will go with the 185/65/14 B-381 Bridgestones. These are ever so slightly taller than the oe 175's. Has anyone made the change and are there are any issues (spedo differences?) that would make this tire purchase a "no-no"?

Thanks in advance
Jim

Don't you mean the "185/65/15" size tire?

Goodness, our 15" wheels are small enough.

[wwu123]

Originally Posted by zonie911

Don't you mean the "185/65/15" size tire?

Goodness, our 15" wheels are small enough.

No, we're talking Gen 1 Prius, original wheels are 14", and 70 aspect ratio. They look small and skinny. I've got 195/60R14 tires right now that are just hitting about 60K miles, and I think I will also go to 185/65R14 for replacements. Not all tires in those sizes are rate for the same load as the OEM XL-rated tires, so something to watch out for.

[zonie911]

My Bad..................

I didn't realize that the 1st gen. cars were on 14" wheels........

and I thought 15" was small.......my bad.

Yes, I do know about the necessity for lrr tires when I get replacements for my 09's OEM tires, but thanks for the remind.

[prius2go]

Check that tyre size bible for width of tyre vs rim width
It also calculates and compares mph vs rolling diameter

[turboj91]

Thanks for the info guys. As far as load ratings, other than me and a full tank of fuel, there is rarely anything of any significance (as far as weight goes) in the car.

[turboj91]

Wow, that "Bible" was a good read. Word is out that some oem tires are now filled with nitrogen from the factory and the mfg is demanding they stay with nitrogen only so shops are having to either sublet the tire inflation or spend $5k on the machine that will generate nitrogen. When you read the "Bible" it makes you wonder "Why" has this been mandated. The engineers should be knowledgeable enough to know that it really does not make much of a difference.

[patsparks]

Originally Posted by zonie911

My Bad..................

I didn't realize that the 1st gen. cars were on 14" wheels........

and I thought 15" was small.......my bad.

Yes, I do know about the necessity for lrr tires when I get replacements for my 09's OEM tires, but thanks for the remind.

I don't understand that 15 inch wheels are small, in the 70s 14 inch was the standard for big cars in Australia so how is a 15 inch wheel small?