Nissan Fb 14

[Cheths]

HI..... I'm having a Nissan FB 14 super saloon. I want to change the tyre size. My existing tyre size is 13". could I change it to 14"?????????????? Do in need to change the Rim set as well????

Plz advice

[MasterDon]

HI..... I'm having a Nissan FB 14 super saloon. I want to change the tyre size. My existing tyre size is 13". could I change it to 14"?????????????? Do in need to change the Rim set as well????

Plz advice

Yes,You have to increase the rim size to 14" to put on 14" tyres.

[Sifaan]

HI..... I'm having a Nissan FB 14 super saloon. I want to change the tyre size. My existing tyre size is 13". could I change it to 14"?????????????? Do in need to change the Rim set as well????

Plz advice

may i ask why you want to change the size?

you'll have to pay to upsize the rims, and you'll have to get lower profile tyres than what you currently use, which will make the ride less comfortable and tyres are more prone to sidewall damage.

and unless you're switching from 13" steel rims to 14" alloys, the unsprung weight will also increase.

larger rims look nicer, but is it worth all the cost and inconvenience?

unless someone is giving you a free set of alloys, or a free set of tyres...

[MasterDon]

larger rims look nicer, but is it worth all the cost and inconvenience?

Depends on the individuals taste and preference.I for one,never go below 17" purely for aesthetic reasons,and is prepared to face the cost,loss of comfort/fuel efficiency etc etc that comes with big rims,how im-practical it may seem.

But If this gentleman is increasing his rim size by just one inch for the looks alone,I strongly discourage it because the differance between the two rim sizes,looks-wise is miniscule,and suggest atleast a set of 16s.

[Sifaan]

Depends on the individuals taste and preference.I for one,never go below 17" purely for aesthetic reasons,and is prepared to face the cost,loss of comfort/fuel efficiency etc etc that comes with big rims,how im-practical it may seem.

fair enough; no offense intended to OP, but I kind of assumed that people with those type of preferences don't drive a FB14

[MasterDon]

fair enough; no offense intended to OP, but I kind of assumed that people with those type of preferences don't drive a FB14

Yes,in most cases thats true BUT You'd be surprised how many 'normal' cars are sporting huge rims these days,I guess people are slowly realising the effect a big set of rims and low profile rubbers have on a car's looks.Gone are the days where owners spend a small fortune on a body kit and never change the puny stock rims.

[Isuru Udana]

HI..... I'm having a Nissan FB 14 super saloon. I want to change the tyre size. My existing tyre size is 13". could I change it to 14"?????????????? Do in need to change the Rim set as well????

Plz advice

You have to change the rim set.

But I think it is not good to change the tyre sizes. If you don't use low profile tyres after switching to 14", you will get incorrect speedo-meter and odo-meter readings.

[hakjay]

You have to change the rim set.

But I think it is not good to change the tyre sizes. If you don't use low profile tyres after switching to 14", you will get incorrect speedo-meter and odo-meter readings.

is there a formulae that we can use to calculate correct rim and tyre proflie to use so that the speedo-meter readings are remain same

[Skyline R33]

is there a formulae that we can use to calculate correct rim and tyre proflie to use so that the speedo-meter readings are remain same

The formula I could think up will be using C = (pi)*d and V = s/t

In this case

C1 - area travelled in car in one rotation with wheel wirh diameter d1

C2 - area travelled in car in one rotation with wheel wirh diameter d2

therefore => C1 = (pi)*d1

C2 = (pi)*d2

C1/C2 = d1/d1 ------- (1)

V1 - The velocity your car needs to pass S1 distance in t1 time using wheel wirh diameter d1

V2 - The velocity your car needs to pass S2 distance in t1 time using wheel wirh diameter d2

therefore => V1 = S1/t1

V2 = S2/t1

V1/V2 = S1/S2 ------- (2)

S1 = x*C1 - here x is the rpm of the wheel with d1

S2 = y*C2 - here y is the rpm of the wheel with d2

therefore => S1/S2 = x*C1/y*C2 ---- (3)

V1/V2 = x*d1/y*d2

V2 = (y*d2/x*d1)* V1

d1 & d2 are your wheel sizes and you could measure x & y. V1 will be the velocity your speedo shows with factory wheels d1 the new wheel size is d2. t1 will be a constant in both speeds. with these you should be able to calculate the new speed.

[Sifaan]

The formula I could think up will be using C = (pi)*d and V = s/t

(snip)

d1 & d2 are your wheel sizes and you could measure x & y. V1 will be the velocity your speedo shows with factory wheels d1 the new wheel size is d2. t1 will be a constant in both speeds. with these you should be able to calculate the new speed.

but all this is for the diameter of the tyre, which is not (directly) specified... diameter of tyre = 2*(width)*profile% + rim size

but width is given in mm and rim in inches so you have to convert: 2*width*profile%/25.4 + rim size

far easier to use an online calculator; there are those that show you the speedometer reading variation (recommended to stay < 3%) for new vs. original tyres based on rim/width/profile

[Pericles]

This really gives new literal meaning to the phrase "re-inventing the wheel" This has all been discussed before. Search it out.

[Skyline R33]

but all this is for the diameter of the tyre, which is not (directly) specified... diameter of tyre = 2*(width)*profile% + rim size

but width is given in mm and rim in inches so you have to convert: 2*width*profile%/25.4 + rim size

far easier to use an online calculator; there are those that show you the speedometer reading variation (recommended to stay < 3%) for new vs. original tyres based on rim/width/profile

True. But when I did thought about the diameter I was thinking of the rim + tyre as a whole and not just the rim size. The easiest will be is to measure the diameter of the wheel with a measuring tape and get the reading in meteres. To get a accurate reading could get 4/5 readings and get the mean reading (this is to prevent the human error due to the curveyness of the tyre).

As you mentioned an online calculator would be the way to go. Best is to recalibarate the speedo or use a GPS with a travelling speed display turned on.

[Skyline R33]

http://www.miata.net/garage/tirecalc.html

found this online cal to get the diameter of your tyre with the size. You might need to get Java runtime to use this.