Wrong tyres fitted?

[Lord Iffy Boatrace]

Hi

 

I bought a 2006 ANH10 about 9 months ago, converted to a full campervan spec. Loving it, but it's got the Japanese tyres from when it was imported on it and whilst they look to have plenty of tread they appear to be 10 years old so want to replace them. They are 255/55/17 and I can't find these tyres anywhere, it seems to be an unusual (at least for the UK) size!

 

So I did some digging and this site https://www.wheel-size.com/size/toyota/alphard/2006/ seems to indicate that the stock size for my Alphard is 225/55/17 (or for 16 inch rims, 205/65/16) - considerably smaller! I'm wondering if the previous owner in Japan put some bigger tyres on for looks. If so this might also explain why my fuel economy is even worse than I thought it would be....also if they are the wrong size then my speedo is going to be out (not by a lot according to https://tiresize.com/tyre-size-calculator/) but stilll...

 

Anyone able to offer any other info that might confirm or contradict my research?

 

Thanks

 

[Lord Iffy Boatrace]

I'm a muppet. I've just gone to check again as it didn't feel right. The tyres fitted are 225/55/17. I misread the (dirty) sidewall.....so all good. 

 

Note to self. Double check next time before spending two hours on tyre websites.....

[Rojie]

3 hours ago, Lord Iffy Boatrace said:

Hi

 

I bought a 2006 ANH10 about 9 months ago, converted to a full campervan spec. Loving it, but it's got the Japanese tyres from when it was imported on it and whilst they look to have plenty of tread they appear to be 10 years old so want to replace them. They are 255/55/17 and I can't find these tyres anywhere, it seems to be an unusual (at least for the UK) size!

 

So I did some digging and this site https://www.wheel-size.com/size/toyota/alphard/2006/ seems to indicate that the stock size for my Alphard is 225/55/17 (or for 16 inch rims, 205/65/16) - considerably smaller! I'm wondering if the previous owner in Japan put some bigger tyres on for looks. If so this might also explain why my fuel economy is even worse than I thought it would be....also if they are the wrong size then my speedo is going to be out (not by a lot according to https://tiresize.com/tyre-size-calculator/) but stilll...

 

Anyone able to offer any other info that might confirm or contradict my research?

 

Thanks

 

 

There are tyre / wheel sizing websites on the internet.

I haven't checked yours above.

 

Something to watch out for is the tyre width.

So, for example only, 255 is 1.5 inches wider than 205.

With any given offset (also important not to change) that will reduce both body to tyre clearance and chassis to tyre clearance by3/4 inch.

The wheel arch and suspension clearances (to the wheel/tyre) under dynamic conditions can alter dramatically; cannot realistically be measured.

 

Changing the type profile will affect your speedo, but, imho, increasing the overall diameter of the wheel tyre combination can exacerbate the clearance issue and is far more important

 

There are many correct and 'safe' combinations (if done properly) and even more that are not !

 

Lowering the tyre profile will, generally, lower the vehicle and increase ride stiffness; unless the rim is increased.

 

Complicated. Yes.

 

Which is why these tyre wheel models are so helpful in maintaining safety.

 

AND, to be pedantic, fitting non-'standard' tyre /wheel combinations is a Modification as far as insurance companies are concerned !

 

Unless changes are radical I would not expect the overall gearing to be changed.

Rolling resistance will be, so that will affect economy; I have no idea by how much. Minor, I expect.

 

Make sure any model you use includes changes to the clearances. They are there for a reason.

[Lord Iffy Boatrace]

4 minutes ago, Rojie said:

 

There are tyre / wheel sizing websites on the internet.

I haven't checked yours above.

 

Something to watch out for is the tyre width.

So, for example only, 255 is 1.5 inches wider than 205.

With any given offset (also important not to change) that will reduce both body to tyre clearance and chassis to tyre clearance by3/4 inch.

The wheel arch and suspension clearances (to the wheel/tyre) under dynamic conditions can alter dramatically; cannot realistically be measured.

 

Changing the type profile will affect your speedo, but, imho, increasing the overall diameter of the wheel tyre combination can exacerbate the clearance issue and is far more important

 

There are many correct and 'safe' combinations (if done properly) and even more that are not !

 

Lowering the tyre profile will, generally, lower the vehicle and increase ride stiffness; unless the rim is increased.

 

Complicated. Yes.

 

Which is why these tyre wheel models are so helpful in maintaining safety.

 

AND, to be pedantic, fitting non-'standard' tyre /wheel combinations is a Modification as far as insurance companies are concerned !

 

Unless changes are radical I would not expect the overall gearing to be changed.

Rolling resistance will be, so that will affect economy; I have no idea by how much. Minor, I expect.

 

Make sure any model you use includes changes to the clearances. They are there for a reason.

Thank you for this. I'm not going to change it - have ordered 225/55/17 which is what's on there and is the OE spec. Don't want any issues!

 

Have ordered Goodyear EfficientGrip Performance 2 tyres - come with good writeups so let's see how they do...

[Rojie]

7 hours ago, Lord Iffy Boatrace said:

I'm a muppet. I've just gone to check again as it didn't feel right. The tyres fitted are 225/55/17. I misread the (dirty) sidewall.....so all good. 

 

Note to self. Double check next time before spending two hours on tyre websites.....

 

That appears to be the correct size for the AS model

[John Harrison]

On 5/24/2023 at 11:43 AM, Lord Iffy Boatrace said:

Hi

 

I bought a 2006 ANH10 about 9 months ago, converted to a full campervan spec. Loving it, but it's got the Japanese tyres from when it was imported on it and whilst they look to have plenty of tread they appear to be 10 years old so want to replace them. They are 255/55/17 and I can't find these tyres anywhere, it seems to be an unusual (at least for the UK) size!

 

So I did some digging and this site https://www.wheel-size.com/size/toyota/alphard/2006/ seems to indicate that the stock size for my Alphard is 225/55/17 (or for 16 inch rims, 205/65/16) - considerably smaller! I'm wondering if the previous owner in Japan put some bigger tyres on for looks. If so this might also explain why my fuel economy is even worse than I thought it would be....also if they are the wrong size then my speedo is going to be out (not by a lot according to https://tiresize.com/tyre-size-calculator/) but stilll...

 

Anyone able to offer any other info that might confirm or contradict my research?

 

Thanks

 

Hi. My 2008 type 20 Vellfire had 205 55 17s tyres on it when I bought it. I bought a translated Handbook shortly after I bought the car and mine should have (and has now) 215 60 17s (Goodyear) the ride is much better now and my cruise control now does the correct 68/9mph on the motorway. It was only doing 63/64mph with the old tyres.

Most tyre dealers should becable to advise.

I used to use Goodyears on my Chrysler Voyager. They were always the best!!!

 

John Harrison. WALLASEY, WIRRAL.

[Rojie]

41 minutes ago, John Harrison said:

Hi. My 2008 type 20 Vellfire had 205 55 17s tyres on it when I bought it. I bought a translated Handbook shortly after I bought the car and mine should have (and has now) 215 60 17s (Goodyear) the ride is much better now and my cruise control now does the correct 68/9mph on the motorway. It was only doing 63/64mph with the old tyres.

Most tyre dealers should becable to advise.

I used to use Goodyears on my Chrysler Voyager. They were always the best!!!

 

John Harrison. WALLASEY, WIRRAL.

 

Hi John,

 

If your machine is a 20 series, can you please change your profile to reflect that.

Or, I can do it for you.

 

Currently, you seem to have a facelifted Generation 1 (Series 10.

[John Harrison]

Hi. If you can do it that would be great. I'm hopeless at I.T.

6 hours ago, Rojie said:

 

Hi John,

 

If your machine is a 20 series, can you please change your profile to reflect that.

Or, I can do it for you.

 

Currently, you seem to have a facelifted Generation 1 (Series 10.