1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Tire Upgrade Review- Toyo Extensa A/S 205/60R15

Discussion in 'Gen 2 Prius Accessories & Modifications' started by skyswordsman, Sep 30, 2011.

  1. SteveLee

    SteveLee Active Member

    Joined:
    Sep 15, 2012
    645
    180
    0
    Location:
    North Carolina
    Vehicle:
    2010 Prius
    Model:
    I
    Sorry I wasn't more clear. I was looking for noticeable differences between the 185, 195, and 205 widths. But I see it isn't a good comparison since there are other factors?
     
  2. SteveLee

    SteveLee Active Member

    Joined:
    Sep 15, 2012
    645
    180
    0
    Location:
    North Carolina
    Vehicle:
    2010 Prius
    Model:
    I
    I was especially interested in the handling differences between the 185/195/205 sizes. But it sounds like it may not be a good comparison with the other mods on your 04. I'm presently running the 185/65R/15 Goodyear Assurance with good MPG, and adequate handling mostly but I do find a bit of steering correction needed and some side wind buffeting. I thought a wider tire might help in these areas.
     
  3. 69shovlhed

    69shovlhed Surly tree hugger

    Joined:
    May 13, 2012
    2,170
    746
    0
    Location:
    Delaware
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    i'm sure the sway bars have an effect, but michelins are very good tires and so i don't have anything bad to say about the handling of the '05 other than body roll. i prefer 205s because they look much better on the oe wheels, and being slightly taller my speedo is more accurate. the 185s would show +2mph difference than the speed cameras which VA likes to use.
     
  4. SteveLee

    SteveLee Active Member

    Joined:
    Sep 15, 2012
    645
    180
    0
    Location:
    North Carolina
    Vehicle:
    2010 Prius
    Model:
    I
    I'm not familiar with the term "body roll". Would that be like a twisting from front to rear? When you say the 205's are slightly taller, is that even with the same height rating, like in the 185/65/15 and the 205/65/15?
     
  5. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,914
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    There seems to be a miss conception that LRR tyres have poorer wet grip than non LRR tyres. In UK/EU all tyres sold have to display by law:-

    (1) The rolling resistance.
    (2) The wet grip
    (3) The noise level (in db)

    The tyres have to be tested by the manufacturer in a standard reproducible way and results are given on a scale of A to G. A being the best G the worst.

    There is only one tyre at the moment produced in only one size that has an AA rating for economy and wet grip, the new Bridgestone Ecopia.

    From my research there are 2 with BA ratings.

    The only tyres I can find with that I would consider are not LRR tyres (rated E for RR) are Michelin energy savers rated A for wet grip.

    All the other tyres are rated C or lower for wet grip. It is also interesting to note that tyre width does not make the difference one would assume with rolling resistance (wider does not mean higher rolling resistance) on some tyres the reverse is true (wider has less rolling resistance).

    I know someone will find a tyre that is not LRR with a B or A ratting if you search through every possible tyre size and make, but I kept to the sizes that people here are likely to use.

    It is also complicated by the fact that some tyre sold in the US are not available in the UK or have different names.
     
  6. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,914
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    Checking the General Altimax HP tyres ratings brings up the results E for economy and C for wet grip.
     
  7. SteveLee

    SteveLee Active Member

    Joined:
    Sep 15, 2012
    645
    180
    0
    Location:
    North Carolina
    Vehicle:
    2010 Prius
    Model:
    I
    Ok, after a little more remedial education i see what you were saying about the tire being a little higher when going to the wider tire. The 65 in the 185/65/15 is the sidewall aspect or height ratio or percentage of the width. If I have this right the sidewall height is 65% of the 185 width. And it would also be 65% of the 205 width. 65% of 205 is slightly more than 65% of the 185,resulting in a slightly higher sidewall for the 205. Seems like I knew this at one time but fell into the thinking that the 65 was the same sidewall height with all widths. I have accumulated lots of info over the years on a few subjects and manage to remember some of it.

    So if I wanted to retain the similar sidewall height when going to a wider tire I would decrease the aspect ratio. You said going to a 205 corrected the height/speedometer relationship so you get a more accurate reading. Or is it? Wouldn't the manufacturers recommended tire size of 185/65/15 be the correct size for the accurate speedometer reading?
     
  8. 69shovlhed

    69shovlhed Surly tree hugger

    Joined:
    May 13, 2012
    2,170
    746
    0
    Location:
    Delaware
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    you would think the manufacturers would set the speedo to be accurate, and maybe on the touring model it is. but w/ the 15s, it reads a little faster than it should.
    i use 205/60r15 tires, and they are just a little taller than stock. tire rack gives height specs.
    "body roll" is when cornering the body leans away from the turn cause it still wants to go straight. the faster you go the more it leans. there is a scientific explanation for it, but thicker sway bars act like a spring to force the body to remain level during turns.
     
  9. F8L

    F8L Protecting Habitat & AG Lands

    Joined:
    Aug 14, 2006
    19,011
    4,080
    50
    Location:
    Grass Valley, CA.
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    A 205/60/15 would help correct the speedo error, provide much better handling/stability, and look a little more substantial than the tiny 185/65/15s. At freeway speeds I expect a slight loss in mpg after the new tires break in. The car would be safer too. The Michelin Defender would be a good choice in that size. The Turanza Serenity Plus is also a good choice if you need wet traction.