Type size from 175/65R14 to 185/65R14

[Jan Athole]

Can I change my tyre size from 175/65R14 to 185/65R14 on the same rims Toyota Yaris Verso 2002

[FROSTYBALLS]

Need to check the effect on the speedometer - if the change makes the speedo under-read (ie show less than the actual speed) it will be illegal.

Enter your sizes into the tyre calculator on the following website against stock tyre and new tyre, and it will do the calculation for you:

https://www.autopartuk.com/tyre-calculator

Any under-reading will be shown in red font.

[Cyker]

I like this site as it shows the comparison very clearly:

https://tiresize.com/comparison/

I think you'd need to goto 185/60 as 185/65 will make the speedo underread!

Why do you want to change out of curiosity? Wider tyres usually mean worse mpg and wet grip, although they can increase tyre life a bit.

 

[davidif]

On 4/2/2022 at 1:31 PM, Jan Athole said:

Can I change my tyre size from 175/65R14 to 185/65R14 on the same rims Toyota Yaris Verso 2002

Unless the larger size is an option for the car, their may be an insurance implication. You might want to run this by your insurer.

[Mooly]

I've recently experienced this question of different tyre sizes on our old Corolla.

Its a 2003 model and had four Maxis budget tyres fitted around 2009 due to cracking in the treads. All good...

2018 and the front pair are showing signs of severe cracking although have worn and lasted better than the originals (Dunlop?) but that's another story...

2018 and the fronts are replaced by a new pair of Maxis. I've always thought they looked very 'kerb friendly' as they had plenty of rubber past the rims... more info to follow.

2022 and sidewall puncture in a rear plus the fact these were now 13 years old and cracked badly had me just look at the sidewall for the details and ask for a pair of budget tyres to be fitted. These were the 2009 fitment and were 195/60R15.

New budgets fitted and they offered to swap wheels putting the new rubber on the front. Nothing was said but I notice  the new tyres seem much less kerb friendly, I check and they are 195/60's as I asked for. I look at the rears (which are those fitted in 2018) and am surprised to see these are 195/65R15 and so have a bigger rolling diameter.

How could I have got that wrong, I went out and wrote the details off the tyre before booking an appointment for them to be fitted. Well it turns out I didn't get it wrong, the 2009 Maxis that were on the rear were correct (195/60) and the ones fitted in 2018 are incorrect. I have the paperwork for those and they are billed as 195/60's.

So I've been driving around with incorrect tyres that cause the speedo to under read which is disturbing because I know the speedo itself will over read by design and so I know for example going through a speed camera at an indicated 32 or 33mph will not be over 30mph with correct tyres but with the incorrect fitment it will.

Those 195/65 are now fitted on the rear.

[FROSTYBALLS]

6 hours ago, davidif said:

Unless the larger size is an option for the car, their may be an insurance implication. You might want to run this by your insurer.

Doesn't matter what was offered as an option. The insurer looks at the standard fitting for that spec of car - in the case of the Yaris Verso either GL or GLS. 

Anything else, even Toyota's optional fittings, would need to be run past the insurer to see whether they consider it a modification.