[Shan2nu]

Originally Posted by [b

Quote[/b] ]185/60R14 on the ikon is perfect for what you seem to be looking for.

Rehaan, there's a reason for why i'm against this size for his car.

Most cars that come with 13 in wheels usually have 175/70 R13s as OE, but in his case it seems his car came with 175/75 R13 (which is wierd). So taking this into account i feel 185/65 R14s will be best suited.

Cars that come fitted with 175/70 R 13s as OE can be fitted with 185/60 R 14s. No matter what you do, make sure the tyre diameter and circumference are as close to the OE figures as possible. Using bigger or smaller tyres can affect your car in other ways.

The very reason, why companies give so many various aspect ratios is, to see that you get a broader, grippier tyre without having to change the diameter and circumference.

So why choose 60 when you can be completely confident that 65 will do the job.

Lancer owner who got it all wrong............

Regards....
Shan2nu

[normally_crazy]

Originally Posted by [b

Quote[/b] ]Most cars that come with 13 in wheels usually have 175/70 R13s as OE, but in his case it seems his car came with 175/75 R13 (which is wierd).

Shantanu,

1) the Ikon came with 175/75 R14 tube type tyres as OE.

2) The dealer gave me 185/70 R14 tubeless Pirellis.

now i am going for 185/60 R14 Michellin Certis

is that fine or should i consider another option ?


Also, ONE BIG PROBLEM.

i have 4 alloys and 1 steel rim ( cost cutting as all mftrs do ) , where will i get the 5th alloy ?? can some one help me ?

cheers

[Shan2nu]

Ok it's 14 in is it? Then it's even more dangerous. That's an error of 6.55%!!

If not for the speedo error, then atleast for the suspenssions sake, dont do it.

Car makers set the suspenssion such that it works best with that OE sized tyres. Playing around with the tyre size will affect handling and may even spoil the suspenssion.

185/70 R14s come closest to you OE size (which is why the dealer gave it to you). But i would reccomend 185/65 R 14s. 60 is way too less..........

As for the steel wheel, i dont' think it makes that big a diff, but make sure you don't use it for a long time.

Regards...
Shan2nu

[Rtech]

Shan2 dude! You're gonna give NC a heartattack man!!

The drop in profile from 70 to 60 is no problem at all! No, it will not ruin his suspension. It will not be dangerous! It is not going to cause alignment problems!

The only negative point would be the slightly lower ground clearance and a little harsher ride. However, I think the Certis would probably give a better ride than what he has on now.

What NC plans on doing is really very minor and will not really affect anything! Put that darn calculator away *!! BTW, according to the tyre size calculator the reduction from his existing 185/65 to 185/60 is just 3.1%, which is really acceptable.

Go for it NC! BTW, I thought the certis came in 185/65 anyways??!! You sure you got that size right there NC?

Rt

[normally_crazy]

yup,

i checked at the tyre dealer and its there in 185/60 and yes

Originally Posted by [b

Quote[/b] ]Shan2 dude! You're gonna give NC a heartattack man!!

almost was there ..never knew changing tyres cud be so stressful !!

cheers

[Shan2nu]

Originally Posted by [b

Quote[/b] ]The drop in profile from 70 to 60 is no problem at all

Rtech, you're forgetting that the OE tyres were 75 not 70. So comming down from 75 to 60 does make a difference.

Originally Posted by [b

Quote[/b] ]reduction from his existing 185/65 to 185/60 is just 3.1%

Wrong again, the tyres on his car right now are 185/70 R 14.

So the difference between 185/70 and 185/60 is 6.02%. Double of what you had calculated.

Regards...
Shan2nu

[Rtech]

Originally Posted by [b

Quote[/b] ]So the difference between 185/70 and 185/60 is 6.02%. Double of what you had calculated.

OOps, I took the wrong size on both counts. Anyways, do you honestly feel that fitting 185/60's are gonna mess up his suspension?? He is not increasing the width, simply lowering the aspect ratio.

Rt

[Shan2nu]

Lowering the aspect ratio without increasing witdh or wheel size, driectly points out one thing, reduced diameter and circumference. this is what you should be avoiding.

I can give NC 3 choices.

1. Stick to his present 185/70 R14 tyres. (Which i know he doesn't want to)

2. 185/65 R 14.

3. 185/60 R15 (increase wheel size so that it compesates for the loss of aspect ratio)



Look at the image above. Diff tyres and wheels but, notice that the overall diameter and circumference remain the same.

If these things didn't matter, then we wouldn't need so many diff aspect ratios.

Regards...
Shan2nu]

[Rtech]

Shan2, don't get me wrong, I'm not saying they don't matter. The example you have above is perfect, but i'm talking here about NC's case in particular. The question is, would changing from 65 to 60 aspect tyres cause damage or other problems to his car. The answer there is no.

If NC has his mind set on 60's, great I say. However, that aside, I really don't think there would be a noticeable difference in performance doing that.

I'm sure we would all love to upsize our tyres, but the main problem we have is cost. And again, I really don't pay atention to what Indian manufacturers provide as OE, so to take that as the base for all calculations is debatable. From a performance point of view, it would be better to see what was provided OE abroad. Chances are the Fiesta abroad was sold with 65 pro tyres on the base model anyway.

One added benefit of lower profile tyres is slightly better acceleration, which is what you need in India...top speed is academic!! However, it would probably increase your FE marginally too while cruising.

Rt

[Shan2nu]

Ok just spoke to NC. Prob solved. According to his manual, his OE tyres were infact 175/65 R 14s LOL. So now, it doesn't make a diff. He can go ahead with 185/60 R 14.

Regards...
Shan2nu

[speedsatya]

Originally Posted by [b

Quote[/b] (normally_crazy @ Sep. 13 2004,21:58)]hey guys,

i just got a thought. suppose i change my OE tyres eg. OE tyres - 175/70 R14 and i change it to 185/60 R14.

Does this change affect the kilometer reading on the speedo ? also any effect on the engine RPM ? what about load on the engine due to increased or decreased rolling resistance ?

cheers

changing to 185/60r14 ( OD=600.599mm for 175/70r14)wud reduce ur ride height by 11.5mm.so ur speedo reading will change.i have heard +-5mm in the OD is acceptable ,but here there is big difference of 23mm in the OD.

the 205/60r14 wud be the best upsize.as the OD is same as the original tires.here od=601.599mm.but u wud have to check if it fouls with any body part while turning and when fully loaded.
otherwise,

i think the ideal upsize wud be 185/65 r14(OD=596.0997) as the difference in OD id just 5mm.here,ride ht=-2mm.
then for 195/65r14,OD=609.0997.,here diff is 9mm.,ride ht=+4mm

205/60r14 is the best,or 185/65 r14.
but u might have to change ur rims for 205 tire.so the 185/65 wud be the best if u wanna keep ur same alloys.

speedsatya

[Rehaan]

Originally Posted by [b

Quote[/b] (Shan2nu @ Sep. 15 2004,11:45)]

Rehaan, there's a reason for why i'm against this size for his car.

Most cars that come with 13 in wheels usually have 175/70 R13s as OE, but in his case it seems his car came with 175/75 R13 (which is wierd). So taking this into account i feel 185/65 R14s will be best suited.

Sure Shan2nu,

But tires with an aspect ratio of 65 are not easily available on the indian market.. hence i said 60.

Either way, i am with Rtech... a 60 profile vs a 65 doesnt make a terrible difference.

Anyway, since u spoke to him..OE tires of 175/65R14 is weird.. never herd of that size on any indian car..!

Also his current tires are 185/70R14 !! thats an upsize in both width and profile!! ....

cya
R

[Shan2nu]

Originally Posted by [b

Quote[/b] ]But tires with an aspect ratio of 65 are not easily available on the indian market.. hence i said 60

Doesn't the Optra come with 185/65 R 14

Neway, it doesn't matter now, read my previous post. According to his manual the OE tyres were actually 175/65 R 14 and not 175/75 R 14. So 185/60 R 14 is fine with me too.

Originally Posted by [b

Quote[/b] ]Anyway, since u spoke to him..OE tires of 175/65R14 is weird.. never herd of that size on any indian car..!

What do you think the Indigo, Ikon, Petra, Palio GTX, Vtec and NHC run on. Check out Rush's Vtec tyres next time, you'll see the same size, printed on them. "175/65 R14 82T".

Regards...
Shan2nu

[speedsatya]

but guys even when he changes his tires ,the width that he has decided on is the same.only the aspect ratio is different.
so:why does he want to change his tire at all.

speedsatya *

[Shan2nu]

Originally Posted by [b

Quote[/b] ]but guys even when he changes his tires ,the width that he has decided on is the same.only the aspect ratio is different.
so:why does he want to change his tire at all.

Using lower aspect ratios does make a diff. Using low pro tyres reduces the distance between the wheel and the road. This helps make the sidewalls less flexible, which inturn improves and sharpens handling.

For EG: It's easier to bend/break a 5 feet wooden stick than it is to bend/break a 1 foot stick.

Regards...
Shan2nu