Volvo V40 Forums banner
1 - 20 of 28 Posts

·
Registered
Volvo V40 D3 Polar+ Sport | 2019
Joined
·
36 Posts
Discussion Starter · #1 · (Edited)
Hallo everyone! Even before buying my car I wanted to upgrade the rims to 18 inch and keep the 17 inch as a winter tire set. I’m interested in the Ixion IV 18 rims. However the are quite expensive.

I noticed that they for sale atm, costing €1275 instead of €1595.
Does this seem like a good price to you?

My current 17 inch tires still got some life left in them. So I would invest in the rims by buying them on sale and then putting them on at a later date!

Wheel Automotive tire Font Rim Alloy wheel
 

·
Super Moderator
Joined
·
641 Posts
It could be a good deal, but remember the cost of the bigger tyres and the harsher ride you will get from the lower profile.

You might also need to take the car to Volvo to get the ECU reprogrammed, larger wheels could need a digital update to the steering rack to prevent the tyres fouling the arches.
 

·
Registered
Joined
·
501 Posts
It could be a good deal, but remember the cost of the bigger tyres and the harsher ride you will get from the lower profile.

You might also need to take the car to Volvo to get the ECU reprogrammed, larger wheels could need a digital update to the steering rack to prevent the tyres fouling the arches.
AIUI, there is both a physical modification to the rack and a software update required. Stops are installed on the rack to restrict movement. The software update applies increased effort (reduced assistance) to the steering when approaching the new stop positions, to minimise the risk of damage to the rack that might otherwise occur due to the steering suddenly hitting the new stops with full power assistance.
 

·
Registered
Volvo V40 D3 Polar+ Sport | 2019
Joined
·
36 Posts
Discussion Starter · #4 ·
It could be a good deal, but remember the cost of the bigger tyres and the harsher ride you will get from the lower profile.

You might also need to take the car to Volvo to get the ECU reprogrammed, larger wheels could need a digital update to the steering rack to prevent the tyres fouling the arches.
Thanks for the tip! When test driving cars I also test drove a another v40 with 18 inch wheels but less option overall. Still enjoyed the ride quility!
 

·
Registered
Volvo V40 D3 Polar+ Sport | 2019
Joined
·
36 Posts
Discussion Starter · #5 ·
AIUI, there is both a physical modification to the rack and a software update required. Stops are installed on the rack to restrict movement. The software update applies increased effort (reduced assistance) to the steering when approaching the new stop positions, to minimise the risk of damage to the rack that might otherwise occur due to the steering suddenly hitting the new stops with full power assistance.
How much can I expect the stops and software update will cost? And do you recommand also running winter tires on another 18 inch wheel set instead of using the old 17 inch wheels ?

Edit: My current wheel size is 225/45/R17. Do I still need the stops installed?
 

·
Registered
Joined
·
30 Posts
AIUI, une modification physique du rack et une mise à jour logicielle sont nécessaires. Des butées sont installées sur la crémaillère pour limiter le mouvement. La mise à jour logicielle applique un effort accru (assistance réduite) à la direction à l'approche des nouvelles positions d'arrêt, afin de minimiser le risque d'endommagement de la crémaillère qui pourrait autrement se produire en raison de l'impact soudain de la direction sur les nouvelles butées avec une assistance complète.
[/DEVIS]
[/DEVIS]

Je n'imaginais pas qu'il y ait autant de modifications 😳

Moi j'ai les 18 pouces d'origine et je passe en 16 pour l'hiver
 

·
Registered
Joined
·
501 Posts
How much can I expect the stops and software update will cost? And do you recommand also running winter tires on another 18 inch wheel set instead of using the old 17 inch wheels ?

Edit: My current wheel size is 225/45/R17. Do I still need the stops installed?
Cost. No idea I'm afraid. Can't check the wheel sizes either as my copy of Vida is on a different PC and I'm currently confined to the wrong room in an attempt not to pass Covid on to my wife or daughter.

I can answer the other question though - well there has to be some good news :D

The reason for fitting winter tyres is to obtain / seek the best available grip in winter conditions. Winter tyres work best when they are flexible, so that they can keep the largest contact patch in all circumstances. Consequently the smallest wheel and largest sidewall profile you can fit whilst keeping the rolling circumference the same, or as close as possible within a couple of percent, the better they will work. Slightly lower pressures than the equivalent summer tyres can also be advantageous, but will increase the risk of wheel and tyre damage on a low profile tyre. Winter tyres on 18 inch wheels will work better than the same size summer tyres on the same diameter wheels. Will they work as well as a winter tyre of the same circumference with a higher sidewall and greater ability to flex? No way!
 

·
Registered
Joined
·
967 Posts
I run all-season 17" tyres on my V40, though its predecessor (a Ford Focus) had two sets of wheels, summer and winter tyres respectively.
My other car still has two sets of wheels, summer and winter tyres.
In both cases my summer wheels were larger rims and lower-profile tyres than the winter set; same overall running diameter. The Focus was 15"/16" the other car is 18"/20" though its predecessor (earlier version of the same model) was 17"/18".
As noted above smaller wheels with higher sidewall are definitely better for winter. You can also use smaller, usually cheaper, wheels that you worry less about if they are damaged.
 

·
Registered
2017 V40 T5
Joined
·
42 Posts


The change from 17 to18“ was easy. I put some 8,5“x18“ on it. The only thing changes is the Tyre size it’s getting smaller when the rim size gets higher i drive 225/40/18 everything fine and didn’t needed to change anything on the car.


Gesendet von iPhone mit Tapatalk
 

·
Super Moderator
Joined
·
641 Posts
The change from 17 to18“ was easy. I put some 8,5“x18“ on it. The only thing changes is the Tyre size it’s getting smaller when the rim size gets higher i drive 225/40/18 everything fine and didn’t needed to change anything on the car.


Gesendet von iPhone mit Tapatalk
Just because you didn't do anything to the car (ie rack stops, software change) doesn't mean that shouldn't have done it!
 

·
Registered
2017 V40 T5
Joined
·
42 Posts
Why would I need? That’s why we have TÜV in Germany so when you do something Volvo already has Documents for it. You can drive 20“ on it without changing anything.


Gesendet von iPhone mit Tapatalk
 

·
Super Moderator
Joined
·
641 Posts
Why would I need? That’s why we have TÜV in Germany so when you do something Volvo already has Documents for it. You can drive 20“ on it without changing anything.
And in the UK we have the Ministry of Transport... however it is immaterial.

Yes you can put 18", 19" or even 20" wheels on the car, BUT, the manufacturer specifies that to do so you need to change the software that controls the steering rack and I doubt that any government agency actually has the software or equipment to check that you have followed the manufacturers instructions and made the required changes.
 
  • Like
Reactions: Terag

·
Registered
Joined
·
501 Posts
The alterations are required for vehicles fitted with 17x7.5 inch wheels, or any 18 inch or 19 inch wheels. The physical installation of deflection limiter components is the same for all wheel types. There are different software updates for the 17x7.5 inch wheels, or for the 18 and 19 inch wheels.

So cars with 17 inch wheels of less than 7.5 inch width do not need the deflection limiters. Those with wider or larger diameter wheels fitted from new will probably have had the modifications installed at the factory.

For all cars that need the limiters and software updates, if they also have Park Pilot Assist, then that function also requires a software update to program the new steering values.

The reason is twofold. Firstly, the larger wheel sizes without the physical alterations and updates present a real risk of expensive damage to the steering rack, as it's operating range is limited by the larger wheel and tyre sizes, and reaching the travel limits whilst full power assistance is being provided could result in expensive or even dangerous component failure over time. That is not a matter that would concern the UK MOT annual inspection, nor I would imagine the TUV, unless a physical failure resulting from the modifications was already apparent.

Secondly, the increases tyre width possible with larger wheels could result in the tyre fouling the chassis or other components during operation, which could result in excessive wear and/or damage to the tyre. Steering or suspension components, or tyres fouling or contacting another part of the vehicle is a failure point if it occurs at the time of the annual inspection test in the UK. I would again imagine that the TUV inspection would be similar. I also have an idea, although I'm not certain, that tyre sizes must comply with the original vehicle manufacturer's recommendations for the TUV test? That is not a requirement in itself for the UK test, unless the tyre is deemed obviously unsuitable for use during the inspection.
 

·
Registered
2017 V40 T5
Joined
·
42 Posts
And in the UK we have the Ministry of Transport... however it is immaterial.

Yes you can put 18", 19" or even 20" wheels on the car, BUT, the manufacturer specifies that to do so you need to change the software that controls the steering rack and I doubt that any government agency actually has the software or equipment to check that you have followed the manufacturers instructions and made the required changes.
You don’t have to change it. When I drive 17“ it’s 245/55/17 and when I put my 18“ on it 225/40/18 the rim is bigger but the Rubber gets smaller and has the same hight as the 17“ when you hold them next to each when you would but on 20“ it would be something like 195/30/20“. That’s why you don’t need to change anything. You only need to change anything if you use Tyres or Rims that are bigger then the Original. Like 235/55/18“ then you gonna have problems.

And here in Germany the Polices checks if you drive illegal wheels sizes and sends you to the TÜV, TÜV knows what you can legally drive on your car, with or without changes.


Gesendet von iPhone mit Tapatalk
 

·
Registered
Joined
·
501 Posts
You don’t have to change it. When I drive 17“ it’s 245/55/17 and when I put my 18“ on it 225/40/18 the rim is bigger but the Rubber gets smaller and has the same hight as the 17“ when you hold them next to each when you would but on 20“ it would be something like 195/30/20“. That’s why you don’t need to change anything. You only need to change anything if you use Tyres or Rims that are bigger then the Original. Like 235/55/18“ then you gonna have problems.

And here in Germany the Polices checks if you drive illegal wheels sizes and sends you to the TÜV, TÜV knows what you can legally drive on your car, with or without changes.


Gesendet von iPhone mit Tapatalk
If your car came from Volvo with 17 inch or larger wheels, it probably already has the deflection limiters and appropriate software. How would you know? You would have to remove the rubber gaiters from the rack to tie rod joints to determine whether the deflectors are present, and know what you are looking for. Alternatively, you/the police/the TUV, may be able to assume the lack of any issues on the absence of demonstrable fouling of the wheels, tyres, steering or suspension components, or signs of the same, during an inspection. Legally, that is all that would concern the authorities. They are not concerned about the longevity of or the possibility of future damage to your steering rack, tyres etc., only the operating condition of the vehicle at that specific moment in time. If the steering rack fails, or the tyres exhibit signs of illegal wear or damage at a future check, then that is something they would deal with as they may feel appropriate at that time. But Volvo recommend the modifications to prevent those issues from arising.
 

·
Registered
2017 V40 T5
Joined
·
42 Posts
If your car came from Volvo with 17 inch or larger wheels, it probably already has the deflection limiters and appropriate software. How would you know? You would have to remove the rubber gaiters from the rack to tie rod joints to determine whether the deflectors are present, and know what you are looking for. Alternatively, you/the police/the TUV, may be able to assume the lack of any issues on the absence of demonstrable fouling of the wheels, tyres, steering or suspension components, or signs of the same, during an inspection. Legally, that is all that would concern the authorities. They are not concerned about the longevity of or the possibility of future damage to your steering rack, tyres etc., only the operating condition of the vehicle at that specific moment in time. If the steering rack fails, or the tyres exhibit signs of illegal wear or damage at a future check, then that is something they would deal with as they may feel appropriate at that time. But Volvo recommend the modifications to prevent those issues from arising.

As you see the Rubber gets smaller the bigger the Rims get. The Hole Wheel size doesnt change that’s why you don’t have to change software or deflector.


Gesendet von iPhone mit Tapatalk
 

·
Registered
Joined
·
967 Posts
I suspect the main difference is that "typically" larger wheels have wider rims/tyres so there is a risk of fouling.
They also tend to have a wider/flatter profile so while the CENTRE of the tread may be in almost exactly the same place, the EDGE (which is what will be fouling) will be further out.
I know that in practice that affects stowing the spare wheel on my other car which has two sets of wheels (summer and winter). The summer set are "logically" exactly the same size (and width) but in practice they are a different tyre shape and the summer one is a VERY tight fit in the spare wheel well (yes it has one!).
I also noticed that I can easily get two of the winter wheels (with tyres) in the boot but only one summer one.
 
  • Like
Reactions: RS3100

·
Registered
Joined
·
501 Posts

As you see the Rubber gets smaller the bigger the Rims get. The Hole Wheel size doesnt change that’s why you don’t have to change software or deflector.


Gesendet von iPhone mit Tapatalk
It has nothing to do with the overall diameter. The tyres shown in your list range from section widths of 185 mm to 235 mm. Larger section widths require wider wheels to safely accommodate the tyre fitment. The permitted wheel widths for various tyre sizes are published by ETRTO, and whilst there are permitted ranges for each tyre size that are legally allowed, Volvo along with other vehicle manufacturers will always specify the optimum wheel width for any tyre size that they permit. If you change a 6 inch width rim for a 7 inch width rim, the edge of the rim will project half an inch further towards both the inside and outside of the vehicle, all other things being equal. A tyre with a wider section width also does the same, and the wheel may not be capable of being turned on full lock without the tyre fouling or the edge of the rim coming into contact with another part of the vehicle. A 235mm section width tyre will project approximately 25 mm further to each side than a 185 mm section width tyre fitted to the same hub, rim offset etc. all being equal. That might be obvious, or might only happen under full suspension deflection, in which case it will not be apparent during a static check such as a safety inspection unless there are tell tale signs of rubbing or wear on the affected components.

Yes you can get around that to an extent by changing the offset of the larger wheel, but that in turn affects the overall handling of the vehicle and could exacerbate the risk of fouling by the outer edge of the tyre if the offset was changed to avoid the risk of fouling the inner edge for instance.

Edit: As more succinctly explained by @HPsauce above ;)(y)
 
1 - 20 of 28 Posts
Top