I did some maths and thats what I found

[a_n_memon88]

Please Do comment on my calculation and if somebody wants any explanation for my calculation I am ready. When we move from stock tire size we should consider that our speedometer will not show original readings

To calculate distance covered per rotation I have used formula of circumference i.e 2XpieXradius. The cars speedometer works with rotation of tire so thats why you get a misleading reading

[usmanulamin]

yrrr i hate maths ... but ur calculations are nice ... gud job

[shaizy007]

kuch bhi samajh nahi aaya

[shahzadnaeem86]

ye to kabhi soocha hi nahi tha

[a_n_memon88]

kuch bhi samajh nahi aaya

Bhai kehnay ka matlab hai kay jab aap apni gari key tire size stock say change karo *** toh speedometer wrong reading day ga

[levin]

In future , How will you expect a site user who is looking for tire size speed variation to trace yr post ?

after 10 months someone unknown person will search" i did some maths" and click search button?

[Bang]

So if i i put 20'' on my car motorway patrol will be on my behind?

[afnan_88]

better than this

Tire Size Calculator - tire & wheel plus sizing

[vague_one]

An the solution to this is ????

[sinner__]

@ poster ur absolutly right in ur calculations ! the speedometer does not shows us the speed of tyres ! if u chek ur speedometer cord u will see that it is conected on the top of the gear box ! if u change tyre size from stock to some other larger one the diameter is increased and automatically the circumfrence is increased and tyres would cover more distance and have more speed than the stock ones ! in my personal experience 185/70/R13 is almost equal in diameter to 205/45/R16 ! mostly guys when changing from stock size to any other they install a low profile ! which has no effect on the speed because the profile is lowed if the rim size is increased in the other case

@vague one
solution to this is that when u change the stock tyre size e.g 175/70/R13 to any other like 16" or 17" then keep the profile low like 40 45 or 50 ! the change in speed will be minimum ! correct me if im wrong !

@a_n_memon88
ur calculation is correct and ur rite

[a_n_memon88]

In future , How will you expect a site user who is looking for tire size speed variation to trace yr post ?

after 10 months someone unknown person will search" i did some maths" and click search button?

Than please suggest some good title and I will change it

[a_n_memon88]

So if i i put 20'' on my car motorway patrol will be on my behind?

If you out 20 inch than your car will be showing 80km/hr whereas you will be going at 130km/hr

[a_n_memon88]

An the solution to this is ????

I personally dont know the solution I did this because in my car I used to feel I am going at 60 while the meter would show only 50-55 so I wanted to find out the reason

[levin]

Than please suggest some good title and I will change it

In previous years some senior members have already discuss tire size speed variations so i wont suggest but i rather you select post title yrself which suits it best for all the work you did.

After all, you will be handling most of the quries on the post, Im happy you brought it up for discussion for the new currently active members who may take advantage from it. good work

[a_n_memon88]

In previous years some senior members have already discuss tire size speed variations so i wont suggest but i rather you select post title yrself which suits it best for all the work you did.

After all, you will be handling most of the quries on the post, Im happy you brought it up for discussion for the new currently active members who may take advantage from it. good work

First tell me how to change the title

[fahadwizz]

you are correct with your calculation, thats why it is recommended to select a compatible tire size based on a similar calculation

Kindly check
Tire size calculator

[virtuostica]

Ok here's another question, if we increase Tire & Rim size... we go faster? right?

Now does that in anyway help in fuel economy? cuz we r covering more distance in same time... ? any ideas about that?

[tarikewl80]

false calculation...
Speedometer depends upon rotation of wheel not rim/tyre size...
therfore there is no change of speedmeter's device in carz like XLI/Altis... City/Civic, Alto/Swift etc....
Rather, they have mentioned it or noted it down in precautionary note book......... not even Mercedez, BMW has warned this.....
so enjoy n luks great in Big Rims,,,,,,,(H)

[anwarior]

although am not sure abt the calculations but i apreciate you bring up this interesting thing!

[ahsanonline]

Ok here's another question, if we increase Tire & Rim size... we go faster? right?

Now does that in anyway help in fuel economy? cuz we r covering more distance in same time... ? any ideas about that?

bigger rim+tyre = more weight that engine has to spin. so more workload if accelerating. and so lesser fuel economy....