Change The Typre Size

[sira]

Hi Guys

I'm hoping to change my car tyres to 14inch . Currently i got 185/70R/13. planning to 185/70R/14. so need to change the rim size too. Before that i'd like to know the pros cons

will this change affected to

1. Pulling power of the car

2. Incorrect Speed and millage - because tyre size is big

3. Improve the handling?

4. Breaks

any other improvement or harm

Please let me see your views on this

Car model - Honda EK3 Exi 98.

Sira

[HardHat]

Probably most of you guys know this and there may have been previous threads, however while we are on the subject, this is how it works:

Stock tyre: 185/70R13

Rim diameter = 13inches

13inches x 25.4mm/inch = 330.2mm

Tread width = 185mm

Side wall height = 185 x 70% = 129.5mm

Diameter of the wheel (d) = 330.2 + (129.5x2) = 589.2mm

Therefore circumference of the wheel (pi x d) = 3.142857 x 589.2 = 1851.8mm

And there are a zillion calculators on the web to do the above calc.

New Tyre 185/70R14

Do the same math for a 185/70R14 wheel and you get the circumference of 1931.6mm.

Thats 104.31% of the stock wheel circumference, meaning 4.31% increase. You will be doing 104.31km/h when your speedo shows 100km/h.

Apart from the error in speedo, car will suffer a reduction of pulling power and the transmission is likely to stress more in acceleration.

So as a thumb rule, stay clear of increasing wheel circumference if possible.

If you must increase rim size, go for a lower profile tyre. For example, you can do 225/55R14 and still will be at 98.13% of the stock wheel circumference.

However, with all the rough road surfaces and pot holes and speed humps and what not on SL roads, a lower profile tyre will fetch its own raft of problems.

Furthermore, bigger wheel diameter is also likely to impede and not improve the handling.

I think there are quite a few members in the forum who have been there done that in fiddling with rim and wheel sizes, who could bring more light into this subject.

Edited May 14, 2013 by HardHat

[kush]

I suggest you go for 185/65/14 or 195/60/14 which would minimise the performance and other issues while giving you the looks and handling of the low profile

[tiv]

  On 5/14/2013 at 1:48 AM, HardHat said:

Probably most of you guys know this and there may have been previous threads, however while we are on the subject, this is how it works:

Stock tyre: 185/70R13

Rim diameter = 13inches

13inches x 25.4mm/inch = 330.2mm

Tread width = 185mm

Side wall height = 185 x 70% = 129.5mm

Diameter of the wheel (d) = 330.2 + (129.5x2) = 589.2mm

Therefore circumference of the wheel (pi x d) = 3.142857 x 589.2 = 1851.8mm

And there are a zillion calculators on the web to do the above calc.

New Tyre 185/70R14

Do the same math for a 185/70R14 wheel and you get the circumference of 1931.6mm.

Thats 104.31% of the stock wheel circumference, meaning 4.31% increase. You will be doing 104.31km/h when your speedo shows 100km/h.

Apart from the error in speedo, car will suffer a reduction of pulling power and the transmission is likely to stress more in acceleration.

So as a thumb rule, stay clear of increasing wheel circumference if possible.

If you must increase rim size, go for a lower profile tyre. For example, you can do 225/55R14 and still will be at 98.13% of the stock wheel circumference.

However, with all the rough road surfaces and pot holes and speed humps and what not on SL roads, a lower profile tyre will fetch its own raft of problems.

Furthermore, bigger wheel diameter is also likely to impede and not improve the handling.

I think there are quite a few members in the forum who have been there done that in fiddling with rim and wheel sizes, who could bring more light into this subject.

Interesting reply Hardhat, just out of curiosity, would this affect a diesel as well? with the added torque?

[HardHat]

tiv,

A diesel 4x4 should be able to manage a few notches of wheel upsizing without much struggle, owing to the ample low end torque and the confirguration of the transmission. So guess you already know that as far as your Hilux is concerned. But any serious modifications including huge tyres and suspension lifts and all would also require changing the diff ratios as well, if to be done properly.

[CJ5]

Sira,

What you are trying to do does not seem a good move. What HardHat has mentioned is very true and his advise is spot on.

Check this out too..

http://www.1010tires.com/Tools/Tire-Size-Calculator

Edited May 14, 2013 by CJ5

[tiv]

  On 5/14/2013 at 3:03 AM, HardHat said:

tiv, A diesel 4x4 should be able to manage a few notches of wheel upsizing without much struggle, owing to the ample low end torque and the confirguration of the transmission. So guess you already know that as far as your Hilux is concerned. But any serious modifications including huge tyres and suspension lifts and all would also require changing the diff ratios as well, if to be done properly.

Well yeah was doing a bit of research myself, my standard 255x70R15s are out in another approx 10000-15000km and I was considering using a 31x10.5R15 All terrain, or a 265X75R15 without any mods as I ve seen many vehicles with the setup in stock configuration. But I fear whether it will have an effect on the pulling power of the truck. Any ideas, suggestions?

Apologies to the OP for a minute thread hijacking.

Edited May 15, 2013 by tiv

[Thilina007]

Hope this will helpful too.....

http://www.tyresave.co.uk/choose.html

http://www.kouki.co.uk/utilities/visual-tyre-size-calculator

Edited May 15, 2013 by Thilina007

[amilaart]

Dear Alla,

I need to change my tire and searching tire now.

I found Dunlop Indonesia and Maxxis, Nankang in same price?

what is the best option

pls give me your comments

[Ek3 Ferio]

  On 5/15/2013 at 4:00 AM, amilaart said:

Dear Alla,

I need to change my tire and searching tire now.

I found Dunlop Indonesia and Maxxis, Nankang in same price?

what is the best option

pls give me your comments

I prefer Dunlop Indonesia.

[CJ5]

  On 5/15/2013 at 5:08 AM, Ek3 Ferio said:

I prefer Dunlop Indonesia.

Any particular reason????

[HardHat]

  On 5/15/2013 at 4:00 AM, amilaart said:

Dear Alla,

I need to change my tire and searching tire now.

Mate why are you praying to God for a simple matter like a tyre change?

[Crosswind]

  On 5/15/2013 at 7:40 AM, HardHat said:

Mate why are you praying to God for a simple matter like a tyre change?

Probably because of the prices of tyres these days