what tyre size???? please help

[matttingle]

im upgrading to 17" and have been quoted 2 different tyre sizes.....

the majority of quotes have been for 205/50/17

have just been told 225/45/17 will give better footprint?? - which would be the best option???

[Mez]

225...

[AlexB]

Just make sure that the rims are wide enough.

[Gav]

The 225's will be wider, which is good for increased dry grip, and worse in wet. See https://www.carbibles.com/tyre_bible_pg3.html

[nathan black]

the width i.e 205, 225 is determined by the rim. On the other hand the profile i.e 45, 50 is up to you. I run standard reno alloys which are 17 with a 45 profile by 205 wide. I found that the diamater of the wheel including tyre was only increased by 5mm. So i advise 17/205/45

[Anthony]

Renaults standard fit for the 17 inch wheel is 205/50/17. So if you have 45 profile tyres you are actually running a smaller tyre than recommended and your speedo will be out, by quite alot.

[matttingle]

difference in speedo is minimal. speedo will read say 60mph and actual will be 60.2'ish mph

[rjacko]

difference in speedo is minimal. speedo will read say 60mph and actual will be 60.2'ish mph

depends on how accurate speedo is to begin with, and being renault I wouldn't trust it to be

Have got renault alloys which are fitted with 205/50/17 as std. Even with these I get higher reading with sat nav when speedo says 60, at around 70 on speedo sat nav is 73-74. Only way to be sure is have it checked and calibrated. tho not sure how or who you'd go to get that done.

[Anthony]

All speedos are made to read slower than you are actually going so people don't get caught out all the time.

The difference is quite big actually. Going from a 50 to a 45 tyre with the same section width decreases the overall diameter by about 20mm. It means you speedo reads about 67 when doing 70.

Plus that to the fact that they wouldn't fill the arches half as good as the correct tyres, so why bother.


Edit: This isn't aimed at you mattingale, you have chosen the correct size tyres.

[onlydiesels]

[quote="Anthony"]All speedos are made to read slower than you are actually going so people don't get caught out all the time.
/quote]

would this not actually mean that you would get caught out

the speedometer actually reads slightly higher than actual speed you`re traveling at.

[nathan black]

if your tyres are a 45 profile and standard ther where a 50 profile that is a difference in diamiter of 10mm dont no where you got 20 from

[Anthony]

All speedos are made to read slower than you are actually going so people don't get caught out all the time.
/quote]

would this not actually mean that you would get caught out

the speedometer actually reads slightly higher than actual speed you`re traveling at.

Oops, sorry that is what I meant!

[Anthony]

if your tyres are a 45 profile and standard ther where a 50 profile that is a difference in diamiter of 10mm dont no where you got 20 from

Go on here and see for yourself: https://www.alloywheels.com/tyrecalc.asp

They are way out.

[matttingle]

thanks for all advice...think i will stick with 205/50/17......
just trying to hunt down the best deal on alloys at moment

[rteone]

If you fit different sized wheels than what car came with you should get the abs module reconfigured for the different tyre size as they all have a different code number .It is done with the renault Clip diagnostic pc.I got mine done when changed wheels,and it will keep speedo reading correctly.