is 195/45/15 the same as 185/55/14????? - Saxperience

MidlandVtr · 8th April 2008, 19:16

im taking my car to le mans in a couple of months so im starting preperations of sorting the little bits i need. One of which is i need to have a spare wheel i can use and is the same size perfectly as my alloys because if i get a puncture the last thing i need is to have to drive 500-1000 miles with a wrong size wheel on one corner.

basically my alloys are 195/45/15, is the only way i can get a spare to buy a single vts alloy or is the mark 2 vts spare wheel the same size( and if so i bet they are never up for sale) or can i use one of my old vtr alloys with 185/55/15??

any help appreciated. cheers

jazzsingh51 · 8th April 2008, 19:24

Ive got a 15" steel spare that you can use with your VTS wheel bolts, with a new michelin tyre - for sale aswell!!

http://www.saxperience.com/forum/sho...d.php?t=132797

MidlandVtr · 8th April 2008, 19:28

thatd be ideal but your wheel has got 195/50/15 and mine have got 45 so it wouldnt fit properly

MidlandVtr · 8th April 2008, 19:29

so really the only replacement would be a wheel with exactly the same inch and profile

sharpie · 8th April 2008, 19:32

Quote:

Originally Posted by MidlandVtr

so really the only replacement would be a wheel with exactly the same inch and profile

no - read my first post again. you could use a 14" wheel as a spare when you're running 15s as long as it has a larger sidewall. in this case 55/14 is approximately the same as 45/15.

JC-Furio · 8th April 2008, 19:36

Quote:

Originally Posted by MidlandVtr

so really the only replacement would be a wheel with exactly the same inch and profile

that would be the ideal replacement - but other combinations can work, may just look a bit odd and not sure if that's illegal or not.

Quote:

Originally Posted by MidlandVtr

thats shocking i didnt realise there would be that much difference

1.4cm isn't huge, but i wouldn't use that tyre as a spare lol. Just pray you don't get a puncture, or get another 195/45/15

MidlandVtr · 8th April 2008, 19:48

ive got team dynamic monzas with 195/45/15 yokos on. i do understand that i could use it and itd virtually be the same but would you drive anywhere up to 1000 miles bumping as you go with a very slightly out wheel, im guessing even if its 1mm out itl make the car judder like the balancing or tracking is out

sharpie · 8th April 2008, 19:26

no.

185/55/15 is taller then 195/45/15.

the numbers mean width(mm)/sidewall height (%)/rim size (inches).

but if you mean 185/55/14 (standard vtr tyres) then this has approximately the same rolling radius as 195/45/15

although i wouldn't push hard on it (as with any spare) but should be fine for any distances.

JC-Furio · 8th April 2008, 19:30

Quote:

Originally Posted by sharpie

no.

185/55/15 is taller then 195/45/15.

the numbers mean width(mm)/sidewall height (%)/rim size (inches)

just to make clear - sidewall height (%) is of the width. (i think lol)

so your looking at 55% of 185 & 45% of 195.

55% of 185 = 101.75

45% of 195 = 87.75

so would be a considerable size difference

MidlandVtr · 8th April 2008, 19:31

thats shocking i didnt realise there would be that much difference

JimoVTR · 8th April 2008, 19:32

Keep to the same tire size.... if your spare is different, buy another one!

my boss was taken to court a few years back for giving a tire the wrong size.(with no idea what it was going on, the bloke asked for the wrong size)

Its against the law for one... and in very unlucky circumstances cause crashes

MidlandVtr · 8th April 2008, 19:34

ok my next question has anyone got a vts wheel or a 195/45/15 spare i could borrow or buy lol

sharpie · 8th April 2008, 19:34

Quote:

Originally Posted by MidlandVtr

ok my next question has anyone got a vts wheel or a 195/45/15 spare i could borrow or buy lol

do you understand that you could use your vtr wheel though? you wrote the wrong tyre size at the start (assuming its a standard toulouse wheel) which has confused this thread.

sharpie · 8th April 2008, 20:37

it will corner scarily with one different sized wheel. i nearly spun my clio while not really driving that hard while running a smaller sized spare.

a vtr wheel with 55 profile has virtually the same rolling radius as your monzas on 45.

gd16 · 8th April 2008, 20:55

Quote:

just to make clear - sidewall height (%) is of the width. (i think lol)

so your looking at 55% of 185 & 45% of 195.

55% of 185 = 101.75

45% of 195 = 87.75

so would be a considerable size difference

JC-Furio - are you forgetting to bare in mind the space in the middle

195/45R15 = 556.5mm diameter, 1748.29 mm circumference
185/55R14 = 559.1mm diameter, 1756.46 mm circumference

All in all - not a great deal of difference.

Only reasons you may not want to use a 14" as a spare is because it doesn't fit over your brakes. Or the fact its technically illegal. Both wheels/tyres on the same axle must be the same size.

I guess if you can prove you've had a puncture - and you're going straight to a garage to get it repaired/replaced - you might be let off. But depends if you're willing to risk it, as i don't know how harsh the penalty is.

sharpie · 8th April 2008, 21:44

Quote:

Originally Posted by gd16

Or the fact its technically illegal. Both wheels/tyres on the same axle must be the same size.

i know that this must be true to pass an mot but there are a fair amount of cars with "space saver" spares that are like bike tyres, so i doubt it's illegal to drive with two different wheels on one axle.

gd16 · 8th April 2008, 22:35

Quote:

Originally Posted by sharpie

i know that this must be true to pass an mot but there are a fair amount of cars with "space saver" spares that are like bike tyres, so i doubt it's illegal to drive with two different wheels on one axle.

I think the disclaimer on the reads that you must only use the space-saver in order to get to a garage to repair/replace your flat tyre.

But i do see a lot of folk driving round with them on as if they're regular tyres.

But its a good arguement if you get stopped with any wheel/tyre the wrong size and the police pick up on it - its ok for space-savers to be a different size.

However - chances are they'll try and do you for it anyhow. Or find something else thats wrong.

JC-Furio · 8th April 2008, 23:54

Quote:

Originally Posted by gd16

JC-Furio - are you forgetting to bare in mind the space in the middle

195/45R15 = 556.5mm diameter, 1748.29 mm circumference
185/55R14 = 559.1mm diameter, 1756.46 mm circumference

Oops. My bad lol. Thanks for correcting

I blame it on the 4 hours of sleep i had last night

Ste · 8th April 2008, 21:13

Due to shit tyres ive got 13" rims on the front and 15" on the back.

Fronts running 215/50/13 and rears running 195/40/15. Car doesn't handle bad or have any strange characteristics but the tyres are both Kumho shite so the handling isnt amazing anyway.... but i can still give it some and not have to panic.

Andy72 · 8th April 2008, 21:46

i use this to calculate tyre sizes

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