tyres

[stupot]

all my tyres on vec sri are due for renewal.they are as you might know are 215 50 17.they are quite expensive as they are an odd size apparantley.been told by a couple off tyre fitters to fit 235 50 17 as they are cheaper and are the same rolling cercumfrance as the originals.i know they will look alot wider which i think is agood thing but has any one fitted the 235s and do they catch in any way.cheers boys for any advice

[denzo]

How much are Vx charging for the GoodYear Eagle NCT5 215/50 R17 ?

Most tyre dealers should get these in (shouldn't they) particularly if Vx are throwing them on all vectra's with 17" wheels?

My Volvo has 20/50 R17 .. which is even scarcer :(

Denzo

[CBR600FV]

How can a 235/50-17 have the same rolling circumference as a 215/50-17. The tyre is 20 mm wider in section, so the tyre will be exactly 10mm taller at a 50% aspect ratio.

[Bainie]

225/45 x 17 is what you are looking for mate, 235/50`s will be a lot taller then the originals ?

[Drinky]

ive just done all the leg work on this one m8 best deal i came up with was 225/45/17 avon zz3 tyres on a Y rating worked out at £ 160 for two and they are an excellent tyre in both wet and dry nice and comfy also quiet HTH ..

[GARY3306]

I too have done a bit of scratching about on this and Bainee and Drinky are confirming what I have found. 225/45x17 are the ones you want Stupot.

[Dwabo]

thats agood price...mine are gettin a bit worn..where are they from?

[stupot]

sorry boys got it wrong wanted 225s.thanx for help.i need new tyers and road tax and its my girlfreinds birthday its gonna be an expensive month.

[GARY3306]

sorry boys got it wrong wanted 225s.thanx for help.i need new tyers and road tax and its my girlfreinds birthday its gonna be an expensive month.

Buy your girlfriend some tyres, then borrow them LOL.

[stupot]

wish i could.like all women she is expensive.

[big phil]

Buy your girlfriend some tyres, then borrow them LOL.
:D :D :D

[Duncan]

CBR600F is correct. How the hell can a 235/50/17 be the same circumference as a 215/50/17, it's going to be a taller tyre.

Bainie is also right - the 225/45/17 is the same rolling radius as the 215/50/17. Far more choice of tyres and less expensive.

The 225/45/17's are actually listed as an alternative size to the 215/50/17's by Vx. I think when my fronts are next for renewal, so will the backs - so I think I'll be switching to the 225's!! :)

D

[big phil]

Duncan , invest in some cyb style wheels mate .... seen a signum with um on .... an it looked the ................ well words can't express !!!! but its a good thing !!

[SAMMYBOY]

Not Wanting To Appear A Smarty Pants, But If 2 Tyres Have The Same Series Ie 50, And The Same Diam Ie 17" They Will Have The Same Circumference

[2ltrT]

looki ere

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

[big phil]

All depends on the width aswell ...ie. 225 ..... the wall ( ie 50 or 45 ) is a calculation between the size of the rim and the width of the tread !!!

so the wall will be different if you had 225 50 17 and 215 50 17 .... the 225 50 17 's wall would be slightly higher mate


Don't know the exact calculation though :)

[Drinky]

tHE 50 PROFILE REFERES TO THE HEIGHT OF THE SIDE WALL IN RELATION TO THE TREAD WIDTH IE ITS 50% 0F THE WIDTH SO IF THE WIDTH IS LARGER THE SIDE WALL WILL BE LARGER RESULTING IN A BIGGER ROLLING CIRCUMFERENCE ...

[SAMMYBOY]

THE ONLY THING THAT WILL AFFECT THE HEIGHT OF THE TYRE IS THE SERIES....AS IN 50mm ETC..ROLLING RADIUS IS A DIFFERENT MATTER THOUGH... EG IF YOU HAVE A 185/60/14 TYRE, TO KEEP THE SAME ROLLING RADIUS, ON EG 15 WHEELS, YOU WOULD NEED TO PUT ON TYRES OF ROUGHLY 185/55/15...

[SAMMYBOY]

I ALWAYS THOT THE SERIES WAS JUST THE MEASUREMENT FORM THE RIM TO THE TREAD, IN mm.......

[Drinky]

Oh bu66er must stop shouting (sorry)

[big phil]

Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
215/50-17 4.2in 12.7in 25.5in 80.0in 792 0.0%
235/35-19 3.2in 12.7in 25.5in 80.0in 792 0.0%

this is calculated by 2ltr t's posted calculater ..... the standard tyre to my 19'' tyre .... bang on the mark !!!!

[Duncan]

Duncan , invest in some cyb style wheels mate .... seen a signum with um on .... an it looked the ................ well words can't express !!!! but its a good thing !!The dog's dangly bits!!?

I'd like to drive a Signum with 19's on to see what the drive is like, as I don't want too much of a harsher ride bearing in mind I have the Irmscher suspension fitted!

D

[SAMMYBOY]

is it just me, or is this getting a bit sad now....lol

[Drinky]

getting TYRED now !!!!!!

[SAMMYBOY]

ive only got 225/40/18`s and its very bumpy, car skips sometimes, and seems to get stuck on white lines sometimes.......my old series 1 RS turbo done this also...

[big phil]

SINCE HAVING 19'S ON I'VE ENHANCED ROAD HOLDING WITHOUT LOOSING TOO MUCH RIDE !!!!

[SAMMYBOY]

not tyred, just a bit deflated

[big phil]

Now i'm shouting

[Drinky]

What was the original question ????????

[SAMMYBOY]

what one?????Drinky, is there any chance you could get me a nice pic of your rear( no funny intended) so i culd photoshop your lights onto my car......sad, but £135 at the end of the day.....cheers if you can

[GARY3306]

Drinky is correct, the aspect ratio, 50, 45 etc is a representation of the depth of side wall in relation to the width of the tyre expressed as a percentage. So on a 225/50x17 the side wall will be roughly 112mm deep (50% of 225). If no aspect ratio figure is used, then the tyre is the standard 80 as in 165x13. So Sammy you are right in a way as well, it is a measurement of the side wall BUT expressed as a percentage of the width.

[SAMMYBOY]

but would that not make your side wall 11cm tall????

[big phil]

I think we were all getting to the same thing ,, just in our different ways !!! LOL

[SAMMYBOY]

my 50 series are only about 50mm high.....

[SAMMYBOY]

need to get the slide rule and the ready reckoner out!!!!!LOL

[GARY3306]

but would that not make your side wall 11cm tall????

Yes

[SAMMYBOY]

i went onto a saddos guide to tyres site, i now know all there is to know.......i will be correcting our technicians tomorow...lol

[Bainie]

what one?????Drinky, is there any chance you could get me a nice pic of your rear( no funny intended) so i culd photoshop your lights onto my car......sad, but £135 at the end of the day.....cheers if you can

Check out Green Growlers car on Vectra-sport.com mate, he has a black C with dark lexus lights ...

[SAMMYBOY]

cheers ill go for a look now....

[h01den]

hi m8 ive got 2 215/50/17 4 sale pm me or ring me if intrested

[big phil]

i've got 4 , but they're on gsi wheels !!!!

[stupot]

fu**ing hell boys.it all went a bit silly there.i am now more fu**ing confused than before!

[h01den]

fu**ing hell boys.it all went a bit silly there.i am now more fu**ing confused than before!

that dont take 2 much with u m8 lol

[stupot]

you cheeky tw*t.will look at them tomorrow.just got to find another two now.

[big phil]

ok stu .... keeping it simple mate

your tyre size at the mo

215/50-17

now if you wanted a wider tyre (225) you drop a profile size to keep the same rolling radius ,
So it would be a 225/45-17

As i have done with my 19'' rims , i've gained 2'' on my rims , so i need to reduce my profile by quite a bit , so have gone for a 35 profile with a 235 width .... 235/35-19

usually if you want to gain a width size you would reduce a profile size , as if you wanted to increase the rim size you again would have to reduce the profile to compensate for the extra hight the rim would give !!

so i've increased my rim x2 sizes and increased my tyre size by 2 sizes = 4 ....2 width and 2 rim , so in theory i should reduce my profile by 4 sizes 50-45-40-35 there you go 235/35-19 A perfect match

any good for you ?

[stupot]

fantastic mate.i am not the sharpest tool in the box!

[big phil]

don't be silly ..... everyone needs the info from time to time !!!! :D

regards

phil

[h01den]

gald u put that up bigphil as ive always wonderd how they worked out the tyre sizes 4 the differnt size alloys

[MJED]

...you can always use Rochfords Tyre Calculator http://www.rochfordtyres.co.uk/TyreCalc.asp

Mark :D

[Tim2100]

hmmm.

Was thinking about tyres the other day. So here is my caluclations.

Width Profile Wheel (") Dia mm Circ mm Diff 70mph
215 50 17 646.8 2032.0 0.0% 0

195 50 17 626.8 1969.2 -3.1% 67.8
195 55 17 646.3 2030.4 -0.1% 69.9
195 60 17 665.8 2091.7 2.9% 72.1
205 45 17 616.3 1936.2 -4.7% 66.7
205 50 17 636.8 2000.6 -1.5% 68.9
205 55 17 657.3 2065.0 1.6% 71.1
205 60 17 677.8 2129.4 4.8% 73.4
215 45 17 625.3 1964.4 -3.3% 67.7
215 50 17 646.8 2032.0 0.0% 70.0
215 55 17 668.3 2099.5 3.3% 72.3
225 40 17 611.8 1922.0 -5.4% 66.2
225 45 17 634.3 1992.7 -1.9% 68.6
225 50 17 656.8 2063.4 1.5% 71.1
225 55 17 679.3 2134.1 5.0% 73.5
235 40 17 619.8 1947.2 -4.2% 67.1
235 45 17 643.3 2021.0 -0.5% 69.6
235 50 17 666.8 2094.8 3.1% 72.2
240 40 17 623.8 1959.7 -3.6% 67.5
240 45 17 647.8 2035.1 0.2% 70.1
240 50 17 671.8 2110.5 3.9% 72.7


The ones in Bold are less than 1% difference in rolling circumference (mm)

So by that the closest is 235/45 17 or 240/45 17. However I'm not sure if these tyres will fit on the Vectra rims, and if they do the car will probably be over tyred (To much rubber on ground) The other closest are 195/55 17, but who will want skinnier tyres on their Vectra???.

Most reconmendations are for the 225/45 17 which is 1.9% smaller diameter which will mean that if driving at 70mph (Assuming your speedo is currently correct) then actually you would be doing 68.6mph.

Can you tell I'm bored at work??? :D

Tim.

Edited cause damn Html Formating screwed my table, still couldn't get it right!! :mad:

[Bainie]

But who says 215/50x17 is right ? Vauxhall also recommend 225/45x17 .... They also fit 235`s on 19`s so it won`t be over tyred i wouldn`t think.... Gee this thread is fairly rolling (pardon the pun)

[installer]

you could always go to vxl who`ll re input your tyre size into your ecu etc,therefore your car will still be calibratted to your wheels and not worry about your rolling radius and speedos etc being out.you can put any tyre/wheel combo on then.

[installer]

right not read all many pages so soory if I repeat so much

215/55R16 N/A Standard 16" Wheel is the standard wheel on vectra c
215/50R17 0.6% OUT 17" Wheel is wheel on GSi and SRi

So as u can see the 17" with 215/50 is 0.6% out


215/55R16 N/A Standard 16" Wheel is the standard wheel on vectra c
215/45R17 -2.7% OUT 17" Wheel

So as u can see the 17" with 215/45 is -2.7% out

But this info is up for debate as we`re on about changing tyre size not wheel size.

the general recommendation is fo 1% to be out over your original size - has been said upto 3% max.

Now the original size of an SRi or GSi is 215/50 , now whose to say that vxl haven`t already changed the info on those ecus to allow for those tyre sizes.

215/50/R17- N/A
225/45/R17 -1.9% So this would still be out over an original SRi GSi size.

But there is much opinion and debate etc and whose going to moan over being 1 or 2 mph out and thats what the bottom line is.

http://www.powerdog.com/tiresize.cgi is the tyre size calc I use.

[Bainie]

225/45/R17 -1.9% So this would still be out over an original SRi GSi size.



http://www.powerdog.com/tiresize.cgi is the tyre size calc I use.

225/45x17 is also recommended in the user book as a tyre size by vx/opel though ?

[Mrs D]

Hmmm..............just a thought - two days and six pages.......ever thought you boys ought to get out more?!?!?!!?!? lol!! :p ;)

[Bainie]

Hmmm..............just a thought - two days and six pages.......ever thought you boys ought to get out more?!?!?!!?!? lol!! :p ;)


*LOL* and I don`t even have 17`s ....

[installer]

225/45x17 is also recommended in the user book as a tyre size by vx/opel though ?

so is it in parameters OR do you go to vxl and get them to change your tyre size in the ecu etc?

sometimes u get more questions than answers

anyway as I said at bottom it`s still 1 or 2 mph out depends on how bothered u are about speedo acuracy

[CBR600FV]

Try this one lads. Its the best calculator/tyre info I've come across. Saves me all the hassles about working it out the long way. I take my hat off to this guy. Profile %age is of section width and is not exactly the height from the rim to the outside of the tyre and please bear in mind that a tyre deforms slighly under weigh to give a different rolling radius to circumference. http://www.chris-longhurst.com/carbibles/tyre_bible.html

[Duncan]

Wow! Just skipped through bits of that site and the detail/info/attention to detail is just fantastic!!

D