Changing 18” wheels to 17”

[sometimewoodworker]

The title is my question in essence

 

I am considering a Camry (2.5 HEV Premium Luxury variant ) or Accord e:HEV: RS. as my next vehicle. I don’t care about the aesthetics, after all I will spend my time driving it. It makes no difference to me what other people think of the car.

 

However 17” wheels are quieter and provide an arguably better ride. I understand that I may need to replace the breaks but I will retain all the parts that have to be swapped out. The cost of the swap is not a relevant factor for me.

 

comments on this please

[steve187]

1 hour ago, sometimewoodworker said:

 

The title is my question in essence

 

I am considering a Camry (2.5 HEV Premium Luxury variant ) or Accord e:HEV: RS. as my next vehicle. I don’t care about the aesthetics, after all I will spend my time driving it. It makes no difference to me what other people think of the car.

 

However 17” wheels are quieter and provide an arguably better ride. I understand that I may need to replace the breaks but I will retain all the parts that have to be swapped out. The cost of the swap is not a relevant factor for me.

 

comments on this please

you would need to keep the same overall diameter of the wheel and tyres as the original

[sometimewoodworker]

2 hours ago, steve187 said:

you would need to keep the same overall diameter of the wheel and tyres as the original

That is of course a given, and when new the difference between stock Camray 17” and 18” wheels is 0.4mm or 0.06% so effectively no difference. 
 

the Honda 17” and 18” wheels for is 11.9mm or 1.81% so it is classed as FITMENT OK!

[richard_smith237]

6 hours ago, sometimewoodworker said:

comments on this please

 

Its an average car...   so any changes and it will still be an average car - I can't see that changing from 18" to 17" wheels are going to make a notable difference...

 

... Each to their own etc... but I'm not sure why anyone would bother...  unless of course I'm wrong and the ride quality is significantly better, in which case, why didn't the manufacturer do that ?

... I have had harder riding cars, but they had low profile tyres on fancy alloys, 'fatter tyres' would have made a better ride I'm sure.

 

 

[malathione]

Both the profile ratio (obviously) as well as the tire (tread pattern, construction, compound) are at least partly responsible for the NVH and comfort characteristics of a vehicle. Given that you will keep the stock suspension and, given that neither of these vehicles will have a stiff suspension, I'd suggest that any improvements would be marginal, at best. In my opinion, I'd look at tires first, do the research and get tires that are known for their low NVH and high comfort characteristics. BF Goodrich Advantages tend to rate close to the top for both NVH and comfort.

[sometimewoodworker]

8 hours ago, richard_smith237 said:

Each to their own etc... but I'm not sure why anyone would bother...  unless of course I'm wrong and the ride quality is significantly better, in which case, why didn't the manufacturer do that ?

Both manufacturers do actually do exactly that.
In that the wheels with tyres that are effectively the same rolling diameter are fitted to different models 

Toyta 

215/55 R17

235/45 R18

 

Honda

225/50 R17

235/45 R18

 

The reasons for fitting the different wheels are not published but I suspect that they are a marketing choice and that in general there is a perception that bigger are better and provide better performance so increasing the perceived value.

 

I have no idea if there was any consideration of ride quality or more accurately how much weight was given to it.

 

However if there is any improvement in things like softening the feel of road imperfections, pot holes etc. then since I will be driving it for hundreds of thousands of kilometres even slight changes are significant and as I said for my driving which is predominantly at the speed limits on major roads, and costs and cosmetics are not relevant

1 hour ago, malathione said:

Both the profile ratio (obviously) as well as the tire (tread pattern, construction, compound) are at least partly responsible for the NVH and comfort characteristics of a vehicle. Given that you will keep the stock suspension and, given that neither of these vehicles will have a stiff suspension, I'd suggest that any improvements would be marginal, at best.

 But if they exist, marginal is still an improvement 

1 hour ago, malathione said:

In my opinion, I'd look at tires first, do the research and get tires that are known for their low NVH and high comfort characteristics. BF Goodrich Advantages tend to rate close to the top for both NVH and comfort.

That is helpful, do you have places where that kind of research is published, the other requirement will be that the exact tyre models are available in Thailand.

 

8 hours ago, richard_smith237 said:

Its an average car...   so any changes and it will still be an average car - I can't see that changing from 18" to 17" wheels are going to make a notable difference...

Yes they are both average cars and will remain so, but the second statement can be accurately summarised as “I don’t know” can’t it?

[Will B Good]

You can seriously notice the difference on Thai roads????

[sometimewoodworker]

1 hour ago, Will B Good said:

You can seriously notice the difference on Thai roads????

How is your question helpful? Also it should be asked to people who actually know the answers.

How does the geographical location affect the road?
 

Having just driven over 5,000km on U.K. roads I can verify that Thailand’s roads are not remarkably different, and having historically driven for hundreds of thousands of kilometres on Japanese roads there are roads that a much worse than the worst of Thai roads that I have driven on.

 

[Will B Good]

4 hours ago, sometimewoodworker said:

How does the geographical location affect the road?

 

.....and yet you then go on to describe geographical differences....55555

[sometimewoodworker]

49 minutes ago, Will B Good said:

 

.....and yet you then go on to describe geographical differences....55555

And you are making comments that have no value or bearing on the actual question posed

[Presnock]

doesn't putting smaller tires mean that the speed and odometer readings will vary?  I am not a mechanic but I recal it used to mean something different.

[Ralf001]

25 minutes ago, Presnock said:

doesn't putting smaller tires mean that the speed and odometer readings will vary?  I am not a mechanic but I recal it used to mean something different.

 

Did you not read the many posts before your saying one must keep the same rolling diameter ?

[transam]

6 hours ago, sometimewoodworker said:

How is your question helpful? Also it should be asked to people who actually know the answers.

How does the geographical location affect the road?
 

Having just driven over 5,000km on U.K. roads I can verify that Thailand’s roads are not remarkably different, and having historically driven for hundreds of thousands of kilometres on Japanese roads there are roads that a much worse than the worst of Thai roads that I have driven on.

 

Just let the stock wheel tyres pressures down a couple of PSI, job done..😋

[sometimewoodworker]

14 minutes ago, Presnock said:

doesn't putting smaller tires mean that the speed and odometer readings will vary?  I am not a mechanic but I recal it used to mean something different.

If you look the 3rd post you will see that though the actual wheels are smaller the side walls are bigger so the rolling diameter on the Toyota is just 0.4mm  different and the Honda is 11.9mm so while neither will be exactly the same the difference is hardly going to be significant.

 

There again I already know that the numbers are just a rough approximation and I always use the much more exact GPS speed data for speed

 

FWIW at an exact 90kmh the odometer reading on my current vehicle with correct tyre pressures is 92kmh

This incidentally is an early warning of low tyre pressures as if the pressure is a few psi low the reading is 91kmh

 

 

[jvs]

I did the opposite of this on a Mercedes once,drove it for a week and changed it back to original.

More air between you and the road definitely makes a difference so i can see why you want to do this.

It will give more comfort and nor feel like a go kart.

[sometimewoodworker]

1 minute ago, transam said:

Just let the stock wheel tyres pressures down a couple of PSI, job done..😋

Lower tyre pressures do far more than making the ride different, among other things, the tyres run hotter, the breaking distance is longer, the grip on wet roads is less good. There may well be other effects that I haven’t mentioned or know.

[sometimewoodworker]

4 minutes ago, jvs said:

I did the opposite of this on a Mercedes once,drove it for a week and changed it back to original.

More air between you and the road definitely makes a difference so i can see why you want to do this.

It will give more comfort and nor feel like a go kart.

Thanks for a real example it is what I suspected, though of course the actual tyres used will have had an influence. Do you remember the difference in rim size?

[jvs]

Just now, sometimewoodworker said:

Thanks for a real example it is what I suspected, though of course the actual tyres used will have had an influence. Do you remember the difference in rim size?

It was 2 inches.

[transam]

1 minute ago, sometimewoodworker said:

Lower tyre pressures do far more than making the ride different, among other things, the tyres run hotter, the breaking distance is longer, the grip on wet roads is less good. There may well be other effects that I haven’t mentioned or know.

Tell me anyone that knows what their tyre pressures are at any moment in time, most folk don't even bother to check tyre pressures.

I recall my ol' Volvo, and a few other cars, it had different recommended pressures for different number of folk on board, did we drive straight to the garage to top up the tyres, no.🤭

I doubt 2 psi less would be a safety risk, I mean, when drag racing I had 10 psi in the rears, I know straight line stuff, but nothing ever happened racing...😉

[sometimewoodworker]

Just now, jvs said:

It was 2 inches.

I am not sure if a 16” after market wheel will fit or be available, the 1” difference is a standard on models of both vehicles so I’m reasonably confident that there will be no problems, apart of course the fight I may have with the actual dealer. 😉 

[transam]

Just now, sometimewoodworker said:

I am not sure if a 16” after market wheel will fit or be available, the 1” difference is a standard on models of both vehicles so I’m reasonably confident that there will be no problems, apart of course the fight I may have with the actual dealer. 😉 

Look up the tyre pressure difference between the 2 sizes on the same ride..

My ol' 4x4 Vigo had 29 psi, but a lesser model with different tyres had something like 40psi..........

[SpaceKadet]

22 hours ago, sometimewoodworker said:

I don’t care about the aesthetics, after all I will spend my time driving it. It makes no difference to me what other people think of the car.

I think that Accord looks pretty cool. Wouldn't mind as my next car.

[sometimewoodworker]

Just now, transam said:

Tell me anyone that knows what their tyre pressures are at any moment in time, most folk don't even bother to check tyre pressures.

I don’t know about others but I can tell you that at the moment my front tyres are slightly low, I will check shortly and tell you exactly how low they are

 

3 minutes ago, transam said:

I recall my ol' Volvo, and a few other cars, it had different recommended pressures for different number of folk on board, did we drive straight to the garage to top up the tyres, no.🤭

It is the same with all vehicles I have driven. However I do not check after driving as the pressure will be different than recommended.

5 minutes ago, transam said:

I doubt 2 psi less would be a safety risk, I mean, when drag racing I had 10 psi in the rears, I know straight line stuff, but nothing ever happened racing...😉

That is hardly relevant as you drive for seconds not hours and probably have little interest in longevity.

[Yellowtail]

If you want a smoother ride, higher profile tires will really help. The low-profile tires loo \k nicer, and are sportier, in that they will corner better and whatnot. 

 

You could also look at a 205-70-15 or a 205-65-16. 

[SAFETY FIRST]

23 hours ago, sometimewoodworker said:

However 17” wheels are quieter

QUIETER 

 

It's not the size of the wheel, it's the profile of the tyre. 

 

[sometimewoodworker]

52 minutes ago, transam said:

Look up the tyre pressure difference between the 2 sizes on the same ride..

My ol' 4x4 Vigo had 29 psi, but a lesser model with different tyres had something like 40psi..........

There is no difference with my current model

[sometimewoodworker]

36 minutes ago, Yellowtail said:

If you want a smoother ride, higher profile tires will really help. The low-profile tires loo \k nicer, and are sportier, in that they will corner better and whatnot. 

 

You could also look at a 205-70-15 or a 205-65-16. 

Neither are suitable for either vehicle 

[sometimewoodworker]

35 minutes ago, SAFETY FIRST said:

QUIETER 

 

It's not the size of the wheel, it's the profile of the tyre. 

 

Smaller wheels require a different profile so it is automatically correct and you can see them on the listing above.

[Yellowtail]

2 minutes ago, sometimewoodworker said:

Neither are suitable for either vehicle 

Why?

[malathione]

9 hours ago, sometimewoodworker said:

But if they exist, marginal is still an improvement 

10 hours ago, malathione said:

In my opinion, I'd look at tires first, do the research and get tires that are known for their low NVH and high comfort characteristics. BF Goodrich Advantages tend to rate close to the top for both NVH and comfort.

That is helpful, do you have places where that kind of research is published, the other requirement will be that the exact tyre models are available in Thailand.

Yes, improvements do exist, certainly. As for tire testing data, https://www.tyrereviews.com/ is my usual go to. In fact, I remember now they did a test on exactly what you're planning to do a few years ago, a direct comparison between different rim diameters.