Tyre Size Despair!

[Big_Sid]

Someone please help me...

I'm being told so many different things and I don't know who to believe. I'm still trying to get hold of some 17" alloys. I've been told now by two different suppliers that I need to have 205/45/17 tyres fitted because this is what Toyota specify.

All of these wheel and tyre packages come with 205/40/17 tyres and changing to the 45 profile tyres increases the price considerably.

When I question this I've been told that having 205/40/17s will...

Make my rolling circumference different and put my speedo out (which is illegal).

Void my insurance (but the insurance company don't seem to care when I questioned them).

I've also been told that if having 205/40/17's fitted I'd need to sign a liability waiver!!!

I've done some maths...

Current wheels are 16" with 205/50/16 which work out to 605mm diameter.

17" with 205/40/17 are 589mm diameter (smaller overall by 16mm).

17" with 205/45/17 are 609.5mm in diameter (4.5mm larger)

Mr T said they really couldn't see that it made a difference but the guy is going to check with their MOT bloke and get back to me. I don't want to end up with my speedo being illegal or something along those line, but I also don't want to be stuck with a tyre size that's expensive to replace (the 45's seem quite a bit more than the 40's).

I just don't know who I should be listening to here. Any advice would be more than welcome.

Cheers!!! Sid

[holly7]

Someone please help me...

I'm being told so many different things and I don't know who to believe. I'm still trying to get hold of some 17" alloys. I've been told now by two different suppliers that I need to have 205/45/17 tyres fitted because this is what Toyota specify.

All of these wheel and tyre packages come with 205/40/17 tyres and changing to the 45 profile tyres increases the price considerably.

When I question this I've been told that having 205/40/17s will...

Make my rolling circumference different and put my speedo out (which is illegal).

Void my insurance (but the insurance company don't seem to care when I questioned them).

I've also been told that if having 205/40/17's fitted I'd need to sign a liability waiver!!!

I've done some maths...

Current wheels are 16" with 205/50/16 which work out to 605mm diameter.

17" with 205/40/17 are 589mm diameter (smaller overall by 16mm).

17" with 205/45/17 are 609.5mm in diameter (4.5mm larger)

Mr T said they really couldn't see that it made a difference but the guy is going to check with their MOT bloke and get back to me. I don't want to end up with my speedo being illegal or something along those line, but I also don't want to be stuck with a tyre size that's expensive to replace (the 45's seem quite a bit more than the 40's).

I just don't know who I should be listening to here. Any advice would be more than welcome.

Cheers!!! Sid

Hi

I changed my tyres/wheels from 205/50/16 to 215/40/17 I did the calculation from an online tyre size calculator.

I will see if I can find it and pass it to you.

[holly7]

Someone please help me...

I'm being told so many different things and I don't know who to believe. I'm still trying to get hold of some 17" alloys. I've been told now by two different suppliers that I need to have 205/45/17 tyres fitted because this is what Toyota specify.

All of these wheel and tyre packages come with 205/40/17 tyres and changing to the 45 profile tyres increases the price considerably.

When I question this I've been told that having 205/40/17s will...

Make my rolling circumference different and put my speedo out (which is illegal).

Void my insurance (but the insurance company don't seem to care when I questioned them).

I've also been told that if having 205/40/17's fitted I'd need to sign a liability waiver!!!

I've done some maths...

Current wheels are 16" with 205/50/16 which work out to 605mm diameter.

17" with 205/40/17 are 589mm diameter (smaller overall by 16mm).

17" with 205/45/17 are 609.5mm in diameter (4.5mm larger)

Mr T said they really couldn't see that it made a difference but the guy is going to check with their MOT bloke and get back to me. I don't want to end up with my speedo being illegal or something along those line, but I also don't want to be stuck with a tyre size that's expensive to replace (the 45's seem quite a bit more than the 40's).

I just don't know who I should be listening to here. Any advice would be more than welcome.

Cheers!!! Sid

Hi

I changed my tyres/wheels from 205/50/16 to 215/40/17 I did the calculation from an online tyre size calculator.

I will see if I can find it and pass it to you.

Here it is,hope it puts your mind at rest! http://www.1010tires.com/TireSizeCalculato...p?action=submit

[holly7]

Here is a pic of wheel

Another site (a bit simpler) http://www.alloywheels.com/TyreCalc.asp

[Parts-King]

I have the T Sport wheels AND Pirelli tyres 205/45/17 available (in sets of 4) to TOC members for £559 delivered to any UK address

PM me if you want any

Kingo

[Big_Sid]

Yet more mis-information this one from www.potn.co.uk...

"We do have them in stock but your vehicle requires 215/40/17 tyres to keep with the rolling radius and the speedo of the car.

I f you chose 205/40/17 then it would be sold as a non-returnable item to you as this is not the correct tyre.

The Toyo that we would provide would be the T1S."

[japracer]

Right the first thing is handling, having a 40 profile tyre will increase handling, but it will make the car less comfortable (being more stiffer) a 45 profile will be more comfortable (less stiffer) but you'll loose some handling, these will not be much difference but it is there, at the end of the day its what you personally want, you can bolt on 18's with 40 profile straight on if you wanted and you can go up to 225 or 235 width before body work is carried out, the speedo will be affected but so minute you'll not notice it, plus most car speedo's are out, due to age and wear, differences in tyres pressures, most speed camera's if you'r worried about that have a tollerance so say your doing 62-3 they'll let you off because of speedo run out's I think they give around 4% on top of your speed because of this

[DefiantFrog]

I had the 17x6.5" Fondamental's with 205x45x17's P-Zero's. Couple of years ago I swapped to 17x7" Oz Super T's, on 215x40x17 Toyo's (comically, having read this post, from POTN!).

Yes, the speedo is out slightly, but no car is perfect - using my SatNav in various cars and comparing Speedo vs. SatNav speed, there are some interesting ideas of 70mph! I've been in a Pug 307, comparing SatNav 70 to Pug 76, and through to a Xara Picasso, SatNav 70 to Xara 66. Seems to be a huge variance there. Celica Vs SatNav, the Celica is 73 SatNav is at 70.

And I've been through 2 MOT's, and no-one has bettered an eye-lid.

Technically POTN are correct, you should ideally be running on 205x45 (or 215x45, depending on the width of the rims you are getting), but real world its going to make no huge difference with insurance, mot's, etc etc. Be careful about the 'No Return' though. Doesn't sound very nice of them...

[nikc1]

it won't matter if you put 205/40r17 or 205/45r17 tyres on. it's down to your preference really. i would put 205/45r17 on myself as the roads here will turn your wheels into 50p pieces!!!

[Big_Sid]

Thanks everyone for your replies. This whole thing has just confused the hell out of me. I mean, I understand that changing the overall diameter of your wheels and tyres will result in your speedo being incorrect, but as someone mentioned, small changes are acceptable as the accuracy of your speedo will vary anyway depending on tyre pressure and also I suppose the amount of tread wear (comparing a brand new tyre with 6mm etc of tread to a nearly illegal tyre).

I just haven't been able to get a definitive answer from anyone and that's been the main problem. My two options are 205/40/17 or 205/45/17. The first one reduces my overall rolling diameter by 16mm on the stock wheels and the latter increases it by 4.5mm. Based on that I think I will have to go for the latter, because its a smaller figure, AND I didn't want to end up with smaller wheels/tyres than I have currently (205/50/16).

Just to clarify (and I only found this out today lol) but the profile size on a tyre correct me if I'm wrong, is a percentage of the width? So a 205/40 has a profile that is 40% of 205mm, so a 215/40 has a bigger profile etc?

To cut a long story short, this whole mess came about because Rockford Tyres (www.alloywheels.com) messed up my order for some 205/45/17 OZ SuperTurismo GTs. First they called me to say they could only find 3 of the 4 wheels and the delivery would therefore be on Wednesday (today). Then on Tuesday afternoon, they called and said, they've found the wheels but they appear to be used and therefore they wouldn't sell them me. The guy told me to find some different alloys on their site and call them back and they'd knock some money off or throw some locking nuts in for free. I told him that I wasn't interested in any other designs though and asked him if they could order more in from OZ... (this guy was like he was on drugs... totally useless customer service). He asked me to call back today to check again, as he couldn't get hold of anyone.

After the call, I decided that I didn't want to do business with them and emailed them saying to cancel my order. I also phoned them today to cancel the order and was told to call back because their computers were down and they couldn't access the order system... I politely advised the guy on the phone to take a pencil, make a note of my cancellation and sort it out himself when the computers were working (idiots!).

Anyway... I get home today and have a card through the door from Royal Mail... 4 Large Parcels were taken back to the sorting depot!?!? I haven't ordered 4 large anythings except alloys which apparently aren't being sent to me. God knows what's going on now, I'm going to go over to Royal Mail on my way into work tomorrow morning and see what the parcels are.

Moral of the story... don't deal with Rockford Tyres unless you enjoy being dicked around by a bunch of f.e.c.k.less morons.

[Vince W]

Thanks everyone for your replies. This whole thing has just confused the hell out of me. I mean, I understand that changing the overall diameter of your wheels and tyres will result in your speedo being incorrect, but as someone mentioned, small changes are acceptable as the accuracy of your speedo will vary anyway depending on tyre pressure and also I suppose the amount of tread wear (comparing a brand new tyre with 6mm etc of tread to a nearly illegal tyre).

I just haven't been able to get a definitive answer from anyone and that's been the main problem. My two options are 205/40/17 or 205/45/17. The first one reduces my overall rolling diameter by 16mm on the stock wheels and the latter increases it by 4.5mm. Based on that I think I will have to go for the latter, because its a smaller figure, AND I didn't want to end up with smaller wheels/tyres than I have currently (205/50/16).

Just to clarify (and I only found this out today lol) but the profile size on a tyre correct me if I'm wrong, is a percentage of the width? So a 205/40 has a profile that is 40% of 205mm, so a 215/40 has a bigger profile etc?

To cut a long story short, this whole mess came about because Rockford Tyres (www.alloywheels.com) messed up my order for some 205/45/17 OZ SuperTurismo GTs. First they called me to say they could only find 3 of the 4 wheels and the delivery would therefore be on Wednesday (today). Then on Tuesday afternoon, they called and said, they've found the wheels but they appear to be used and therefore they wouldn't sell them me. The guy told me to find some different alloys on their site and call them back and they'd knock some money off or throw some locking nuts in for free. I told him that I wasn't interested in any other designs though and asked him if they could order more in from OZ... (this guy was like he was on drugs... totally useless customer service). He asked me to call back today to check again, as he couldn't get hold of anyone.

After the call, I decided that I didn't want to do business with them and emailed them saying to cancel my order. I also phoned them today to cancel the order and was told to call back because their computers were down and they couldn't access the order system... I politely advised the guy on the phone to take a pencil, make a note of my cancellation and sort it out himself when the computers were working (idiots!).

Anyway... I get home today and have a card through the door from Royal Mail... 4 Large Parcels were taken back to the sorting depot!?!? I haven't ordered 4 large anythings except alloys which apparently aren't being sent to me. God knows what's going on now, I'm going to go over to Royal Mail on my way into work tomorrow morning and see what the parcels are.

Moral of the story... don't deal with Rockford Tyres unless you enjoy being dicked around by a bunch of f.e.c.k.less morons.

If it helps, our other Celica is a Gen7 with premium + style pack which includes the 17" alloys with 205/45/17 tyres.

The speedo is accurate up to 65mph (gps) then it starts to read fast, i.e. speedo says 80mph, gps says 76mph.

[aquazi]

I've tried many tyres sizes.. my experience off them.....

The stock Tsport wheels were 205/45/17 Pzeros.70mph on my speedo = 67 on GPS.

215/40/17 with Dunlop SP9000 = look nice as they are wider and thinner so less rubber. Handling is better, and cheaper than the stock size. 70mph on speedo = 62 on GPS

215/45/17 Proxy R = Fill arches quite nicely (once lowered), More rubber so less harsh ride. Cheaper than stock. 70 mph speedo = 68 GPS.

Also had 225/35/18 (incase you are think about the 18 wheel route)

With regards to speedo accurance you have to remember that new tyres will have a cm more tread than worn tyres, so that also effects the accuracy.

IMO i would never get 205/40/17. You are correct the 40 is a percentage of the first number (205 in this case). Your tyres would be stupidly thin, and if your car isnt lowered would make it look like a 4x4.

I would suggest 215/45/17 Toyo Proxy R. Speedo more accurate than the stock size, more tyre so less harshe ride, esp once lowered, and cheaper then stock size. Can get the tyres for under £70 from camskill.co.uk, then need to get them fitted (place i know does fitting for £7.50 a corner)

TBH the only problem i have found with getting 215/45 tyres is that as they fill the arches more it makes it more difficult to remove the front bumper, which feel like a monthly occurance for me

And another tip... best PSI i have found with 215/45/17 is 33.

[Big_Sid]

I've tried many tyres sizes.. my experience off them.....

The stock Tsport wheels were 205/45/17 Pzeros.70mph on my speedo = 67 on GPS.

215/40/17 with Dunlop SP9000 = look nice as they are wider and thinner so less rubber. Handling is better, and cheaper than the stock size. 70mph on speedo = 62 on GPS

215/45/17 Proxy R = Fill arches quite nicely (once lowered), More rubber so less harsh ride. Cheaper than stock. 70 mph speedo = 68 GPS.

Also had 225/35/18 (incase you are think about the 18 wheel route)

With regards to speedo accurance you have to remember that new tyres will have a cm more tread than worn tyres, so that also effects the accuracy.

IMO i would never get 205/40/17. You are correct the 40 is a percentage of the first number (205 in this case). Your tyres would be stupidly thin, and if your car isnt lowered would make it look like a 4x4.

I would suggest 215/45/17 Toyo Proxy R. Speedo more accurate than the stock size, more tyre so less harshe ride, esp once lowered, and cheaper then stock size. Can get the tyres for under £70 from camskill.co.uk, then need to get them fitted (place i know does fitting for £7.50 a corner)

TBH the only problem i have found with getting 215/45 tyres is that as they fill the arches more it makes it more difficult to remove the front bumper, which feel like a monthly occurance for me

And another tip... best PSI i have found with 215/45/17 is 33.

Thanks... you've convinced me... 215/45/17s ordered for next Tuesday. Rather sadly, I've just had to play Gran Turismo 2 on my PS2, buy a Celica VVTLi (or SS-II as they call it) in silver, lower it and stick OZ SuperTurismo wheels on and then race around and watch the replays. Oh god I am sad. But anyway, its cheaper than a track day :D

[Paul748]

when i ran 205-40-17 i split the wall on my old tyres due to them being the wrong size i contacted wolfrace wheels about this and they said the size i needed was 215-45-17 in my opinion tho id stick to 16 inch rims yeh 17 18 look the nuts but there so weak and bend so easy the celica is a hard ride as it is so sticking the small tyres on there makes em worse u will forever be balancing wheels with the ***** surfaced roads we have in the uk

[gar]

Someone please help me...

I'm being told so many different things and I don't know who to believe. I'm still trying to get hold of some 17" alloys. I've been told now by two different suppliers that I need to have 205/45/17 tyres fitted because this is what Toyota specify.

All of these wheel and tyre packages come with 205/40/17 tyres and changing to the 45 profile tyres increases the price considerably.

When I question this I've been told that having 205/40/17s will...

Make my rolling circumference different and put my speedo out (which is illegal).

Void my insurance (but the insurance company don't seem to care when I questioned them).

I've also been told that if having 205/40/17's fitted I'd need to sign a liability waiver!!!

I've done some maths...

Current wheels are 16" with 205/50/16 which work out to 605mm diameter.

17" with 205/40/17 are 589mm diameter (smaller overall by 16mm).

17" with 205/45/17 are 609.5mm in diameter (4.5mm larger)

Mr T said they really couldn't see that it made a difference but the guy is going to check with their MOT bloke and get back to me. I don't want to end up with my speedo being illegal or something along those line, but I also don't want to be stuck with a tyre size that's expensive to replace (the 45's seem quite a bit more than the 40's).

I just don't know who I should be listening to here. Any advice would be more than welcome.

Cheers!!! Sid

Just remember, size isn't everything!

The speedo may be a bit out but I went past a speed check device recently, in a Yaris with standard wheels and the sign said I was doing 34 when my speedo said 37! I hsten to add, this was in a 40mph zone! If that is typical, you will probably still be about right. One more thing worth noting, low profile tyres, by their own nature, wear out quicker then standard sizes and may make the stearing heavier, adding more wear and tear to the stearing rack and stuff.

If you are on a tight budget and plan on keeping the car for ages, I would advise you to stick closer to standard!

[Big_Sid]

Thanks to everyone for their replies. This forum is superb :D

I've gone with 215/45/17s on OZ SuperTurismo GTs. Hopefully I'll be getting these fitted tomorrow, provided the supplier gets them delivered to the place in Birmingham (they were supposed to be delivered today but weren't!).

Will post some piccies when done.

My current wheels/tyres are 205/50/16 which equates to:

Wheel 16" x 25mm = 400mm + (50% of 205mm = 102.5mm) x 2 = 605mm diameter including tyre. Circumference = 1920.4mm

New wheels/tyres will be 215/45/17 which equates to:

Wheel 17" x 25mm = 425mm + (45% of 215mm = 96.75mm) x 2 = 618.5mm diamter including tyre. Circumference = 1963.6mm

A difference of 13.5mm just a fraction over half an inch bigger in diameter and 43.2mm larger circumference.

So if on the original wheels the speedo was 100% accurate, when doing 70mph according to the speedo on the new wheels, the car would actually be travelling at 71.59mph, which in my mind (bearing in mind most people seem to be saying that the Celica speedo is usually displaying a faster speed that reality) is perfectly acceptable.