Can I change tyre profile without issues?
Discussion
Just wondering if I can change my tyre profile to improve the quality of my ride, currently driving a a3 sportback on 225/45/17 and it's somewhat stiff,
Would I be able to just buy 225/50/17 without any issues?
If not, would I run into any trouble dropping a wheel size?
Sorry, I can imagine this is a rather dump question
Cheers
Would I be able to just buy 225/50/17 without any issues?
If not, would I run into any trouble dropping a wheel size?
Sorry, I can imagine this is a rather dump question
Cheers
You can, I have - Kwik Fit tried to stop me doing it saying I was going to die, but the car it was going on has had 13/14/15 inch wheels on at various stages of it's life and as long as the wheels fit and the tyres didnt rub, I stayed miraculously alive
What you might want to consider though is going down an inch on the wheels and upping the sidewall a little more. There's a website that tells you the right move to make to keep the speedo the same as it was before (note, I'm not saying 'keep the speedo accurate')
I'll dig around for it in a bit if no-one else comes up with it
What you might want to consider though is going down an inch on the wheels and upping the sidewall a little more. There's a website that tells you the right move to make to keep the speedo the same as it was before (note, I'm not saying 'keep the speedo accurate')
I'll dig around for it in a bit if no-one else comes up with it
You're going from 101.25 to 112.5mm of sidewall, so do you have 11mm of room for a larger tyre? This will also change your speedometer readings. - assuming your speedometer is 100% accurate as it is now, at 70MPH you'll actually be travelling at 72.5MPH. A small difference, but one to bear in mind as it could be the difference between getting a NIP and not.
Do you think at extra 11mm is really going to make a huge difference?
EDIT: and to the above, dropping down to a 16inch wheel with a 225/50 will keep the speedometer readings much closer - the previous 70MPH becomes 69.7MPH at an indicated 70.
Do you think at extra 11mm is really going to make a huge difference?
EDIT: and to the above, dropping down to a 16inch wheel with a 225/50 will keep the speedometer readings much closer - the previous 70MPH becomes 69.7MPH at an indicated 70.
Increasing the profile and maintaining the same width and wheel diameter means the radius (and therefore circumference) of the tyre increases. This means taller gearing - lower engine RPM for a given speed, also also speedometer reads lower for a given road speed. In this case the tyres have a difference of about 3.6%, i.e. a 3.6% drop in engine speed and a 3.6% drop in speedometer reading for a given road speed.
Increasing the radius of the tyre means it may also foul on bodywork at extreme steering angles and suspension loadings, though less likely in this case as it's only about 11mm larger in radius.
Typically you try to keep the circumference as close as possible to original values by changing the width and profile of the tyre together. In your case a 205/50R17 is the closest match to a 225/45R17. However, you'd need to check that the width of your wheel rim is suitable for a 205.
Increasing the radius of the tyre means it may also foul on bodywork at extreme steering angles and suspension loadings, though less likely in this case as it's only about 11mm larger in radius.
Typically you try to keep the circumference as close as possible to original values by changing the width and profile of the tyre together. In your case a 205/50R17 is the closest match to a 225/45R17. However, you'd need to check that the width of your wheel rim is suitable for a 205.
Mr2Mike said:
Typically you try to keep the circumference as close as possible to original values by changing the width and profile of the tyre together. In your case a 205/50R17 is the closest match to a 225/45R17. However, you'd need to check that the width of your wheel rim is suitable for a 205.
OP wants to try and improve comfort by running a taller sidewall though, so he'd be no better off with this setup, he'll just have a narrower tyre.Goldbear said:
Just wondering if I can change my tyre profile to improve the quality of my ride, currently driving a a3 sportback on 225/45/17 and it's somewhat stiff,
Would I be able to just buy 225/50/17 without any issues?
If not, would I run into any trouble dropping a wheel size?
Sorry, I can imagine this is a rather dump question
Cheers
In theory yes, assuming you can get tyres in that size.Would I be able to just buy 225/50/17 without any issues?
If not, would I run into any trouble dropping a wheel size?
Sorry, I can imagine this is a rather dump question
Cheers
The profile is a percent of the width, so you are wanting a profile height of 50% of 225mm rather than 45% of 225mm.
This will make the tyre taller.
Potential issues:
- A taller tyre may rub
- A taller tyre will affect your speedo
- A taller tyre will blunt acceleration
- A taller tyre with a higher profile will have more of a bulge from the sidewall. You may need to check the recommend rim width is the same, or at least that your rims are within spec (most likely are)
You are looking at a 25.86" tall tyre over a 24.97" tall one. So all of the above could be issues. And the reality is, it might not actually ride any better. A 15 or 16 rim would make a bigger difference most likely.
I went from a 245/50R16 to a 265/35R18 and I can't say the ride is any noticeably different from the drivers seat. Although I'm sure different cars are more sensitive to such changes.
andy-xr said:
What you might want to consider though is going down an inch on the wheels and upping the sidewall a little more. There's a website that tells you the right move to make to keep the speedo the same as it was before (note, I'm not saying 'keep the speedo accurate')
I'll dig around for it in a bit if no-one else comes up with it
Try this one. http://www.tyresave.co.uk/tyresize.htmlI'll dig around for it in a bit if no-one else comes up with it
LeoSayer said:
Don't expect to notice much difference, if at all.
I drive an A3 sportback on 225/45/17 and also drive the same car on 205/55/16 wheels/tyres. The improvement in ride quality is subtle at best.
I doubt you'd notice much difference. I went from 205/50/17 to 225/45/17 on my Octavia (to get a far greater choice of tyres) and noticed no difference in the ride quality.I drive an A3 sportback on 225/45/17 and also drive the same car on 205/55/16 wheels/tyres. The improvement in ride quality is subtle at best.
I went from 18s to 17s, with bigger profile rubber on my track-only Cayman S and although they looked less exciting than the 18s, or 19s they could have had, the ride improved, the wheels were lighter and it was actually slightly quicker round Snetterton and Brands Hatch.
Secondhand, you should be able to find a set of 16s quite cheap, maybe with good tyres fitted.
Secondhand, you should be able to find a set of 16s quite cheap, maybe with good tyres fitted.
As stated, I'd be dropping a wheel size to gain sidewall and keep the speedo correct, ideally to some other size the manufacturer fitted to other models in the range.
Be aware your insurance will want to know and will likely class it as a modification.
Id be inclined to try different tyres. Unroyal rainsports have particularly soft sidewalls, whereas a lot of new tyres and especially runflats ride terribly.
Be aware your insurance will want to know and will likely class it as a modification.
Id be inclined to try different tyres. Unroyal rainsports have particularly soft sidewalls, whereas a lot of new tyres and especially runflats ride terribly.
Wow didn't expect such a response!
Do you guys think the suspension setup of the 'sporty' sportback would over-ride any changes made to soften the ride via tyre/wheels.
Like some of you said, it didn't make much of a difference. Does the the suspension determine the ride quality to a far greater degree?
Do you guys think the suspension setup of the 'sporty' sportback would over-ride any changes made to soften the ride via tyre/wheels.
Like some of you said, it didn't make much of a difference. Does the the suspension determine the ride quality to a far greater degree?
Just been looking at same issue.
I have 255 55 19 on discovery. Looking to put some winters on that I have in the garage. They are 255 50 19.
Tyre fitter said they would go on but suggested I check with Land Rover, who didn't think it would be an issue.
Have also told warranty provider just in case diff explodes or something..... No idea why it would. Tyre fitter muttered something about it.
I have 255 55 19 on discovery. Looking to put some winters on that I have in the garage. They are 255 50 19.
Tyre fitter said they would go on but suggested I check with Land Rover, who didn't think it would be an issue.
Have also told warranty provider just in case diff explodes or something..... No idea why it would. Tyre fitter muttered something about it.
http://www.willtheyfit.com/
Will give you an indication of the increase in radius, speedo error etc. I've found it very useful in the past.
Will give you an indication of the increase in radius, speedo error etc. I've found it very useful in the past.
Dropping to 16"s will make a little difference, but it's mainly the suspension.
I would wait until the tyres are due (probably not a big enough benefit to justify a big spend), and discuss with a decent tyre place. Sometimes swapping brands can help.
Of course if you're tyres are completely knackered a new set of rubber will always feel better.
I would wait until the tyres are due (probably not a big enough benefit to justify a big spend), and discuss with a decent tyre place. Sometimes swapping brands can help.
Of course if you're tyres are completely knackered a new set of rubber will always feel better.
What tyre have you got on at the moment? You'll get a larger difference finding a soft sidewalled tyre than changing profile.
For reference, 195/65 R15, 205/55 R16, 225/45 R17 and 225/40 R18 are all interchangeable by car manufacturers as they have a broadly similar radius. This is why they're by far the most popular tyre sizes.
Tell your insurance company if you do.
For reference, 195/65 R15, 205/55 R16, 225/45 R17 and 225/40 R18 are all interchangeable by car manufacturers as they have a broadly similar radius. This is why they're by far the most popular tyre sizes.
Tell your insurance company if you do.
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