Wheels - change down?

[scudney]

Buy it or test drive it first,see what you think and then make your decision there after. You might find the ride on the car 🚗 to your liking then again you might not,but first thing first 

[H3XME]

31 minutes ago, Hugh R said:

Thanks, but not actually bought it yet, but don't think wheels would hold me back from doing so.  So if I kept the 18's what tyre configuration (F+R)do you people suggest for comfort and quietness?

225/40R18 front and rear. Absolutely no need to run 245s on the rear. It's just gonna increase drag and noise. When buying tyres, you can see what noise rating they have, so look for that :) There's so many tyres out there I couldn't tell you which is the quietest one.. I shop for grip, not noise. Oh, and btw, I don't think it matters that much. IS250 is pretty well sound proofed as it is. Won't make a huge difference on this car anyway

[Linas.P]

As John says above, try the car first and see if you actually need softer tyres. You may already like it as it is, if not then getting more comfortable tyres will always be an option. Finally, no - you can't fit same size tyres of 17s, both 17s and 18s are staggered. Only 16s have same size. The difference between 17s and 18s is that 17s are the same size rims, whereas 18s both rims and the tyres are staggered. 

[Hugh R]

2 hours ago, H3XME said:

225/40R18 front and rear. Absolutely no need to run 245s on the rear.

But Linus says you can't fit the same size tyres?  What have I not understood?!  At present the car has Kumho F: 225/40 (ZR18 92Y)  R:  255/35 (ZR18 94Y)  And I'm thinking I might prefer Dunlop RT2 all round.  BUT what would be the specs front and rear be the same as these for the most comfortable and quietest ride?

Edited March 27, 2021 by Hugh R
addition

[Linas.P]

3 minutes ago, Hugh R said:

But Linus says you can't fit the same size tyres?  What have I not understood?!

It is Lexus spec for 17s it is 225/245, for 18s it is 225/255. Technically, you have to follow this as it could for example invalidate your insurance (which many "but's").

Could you fit 225 all around... technically you can, but I would not recommend it. Rear tyres actually wears quicker than fronts and car being RWD it makes sense to have wider tyres in the rear. How much wider - that is anyone's guess and preference. On my 18s I had 225/245 instead of 255 and probably would have gone step further for either 235/245 or 225/235... Could this be done - sure it can, actually Lexus IS250 AWD model exists in other regions and it has 235s all around on the same 17" wheels, I believe AWD runs 4x front wheels (8J) on 18" and has 245s all around as well.

Lexus does these excessively wide tyres in rear and narrow in front to give "safe handling" characteristics to the car. Now I say "safe" in quotes, because it is exactly opposite of that - this comes from flawed logic that oversteering is dangerous and understeering is safer. It is probably true for inexperienced drivers in very RWD powerful cars, but IS250 is not powerful. So many manufacturers deliberately makes car balance as such that it understeers before it oversteers and IS250 in corners acts almost like it is FWD car, front looses grip before you could ever get rear to step out.

In either case I would keep wider rears to get approximately same wear and little bit more grip on rear, but not as excessively as Lexus. Neither I would go for square set-up.

[Hugh R]

At present the car has Kumho F: 225/40 (ZR18 92Y)  R:  255/35 (ZR18 94Y)  And I'm thinking I might prefer Dunlop RT2 all round.  So, would be the specs for the Dunlops front and rear be the same as these for the most comfortable and quietest ride?

[Mr Vlad]

From my handbook

 

[Linas.P]

44 minutes ago, Hugh R said:

At present the car has Kumho F: 225/40 (ZR18 92Y)  R:  255/35 (ZR18 94Y)  And I'm thinking I might prefer Dunlop RT2 all round.  So, would be the specs for the Dunlops front and rear be the same as these for the most comfortable and quietest ride?

Dunlop RT2 are great tyres and I do recommended them. They are great all around performance tyre, with good price, grip and wear and that is why I like them, but I am not sure they are most comfortable and quiet tyres you can get for that size.

I am not even sure they would be more comfortable than Kuhmos on the car. Other thing I noticed is that rear tyre size you currently have is incorrect, that is the size for mk3 IS300h and that lower profile will automatically make ride harder. Same circumference from 245/40/R18 would make both more comfortable and more fuel efficient tyre. 

[Hugh R]

13 minutes ago, Linas.P said:

Same circumference from 245/40/R18 would make both more comfortable and more fuel efficient tyre. 

Now I'm really confused.  245??  Handbook only mentions 225 and 255.  And the rear tyre specs were e-mailed from the owner!!  Wow.

[Linas.P]

1 minute ago, Hugh R said:

Now I'm really confused.  245??  Handbook only mentions 225 and 255.  And the rear tyre specs were e-mailed from the owner!!  Wow.

Sorry... tyres are confusing... 🙂 

What I am saying - the car has incorrect size for the model, correct size would be 255/40/R18. Second point - if one fits incorrect size anyway (which may be worth doing), then 245/40/R18 is much better than 255/35/R18 when it comes to comfort and fuel efficiency - yet both have almost identical circumference. Wider tyre (255) always means lower MPG, the lower profile (35) always means less comfortable if comparing two tyres of same model.

[Mr Vlad]

Hugh. Don't be confused. Get the car. See how it drives but give it some time. Looks like the car you're getting has the wrong tyres fitted somehow but don't be put off. If after a good few hundred miles you feel the car is a tad uncomfortable then change the rears to the correct size as per lexus handbook. Clear your head of confusion and simply enjoy the car when you get it.

[nicnac]

IS250 SE-L 2006 comes with 225/40/R18 front and 255/40/R18 rear and rides perfectly smoothly as such ................................

[Hugh R]

OK - Now here's the thing - just been told that rear tyres are fairly close to legal limit and current owner will replace them before selling.  Thus if it's the wrong size anyway I'll request 255/40/R18 as replacements.  The front Kumho are correct specs at 225/40/R18 with v. good depth.  Only question now is WHAT brand should be replacements for rear?  Kumho again or another quiet premium tyre that I can copy onto front in time?  

[nicnac]

7 minutes ago, Hugh R said:

OK - Now here's the thing - just been told that rear tyres are fairly close to legal limit and current owner will replace them before selling.  Thus if it's the wrong size anyway I'll request 255/40/R18 as replacements.  The front Kumho are correct specs at 225/40/R18 with v. good depth.  Only question now is WHAT brand should be replacements for rear?  Kumho again or another quiet premium tyre that I can copy onto front in time?  

Kumho are good tyres .and relatively cheap . Go with these again is my recommendation . 

If you were going all 4 ...I am a big Michelin fan 

[Linas.P]

27 minutes ago, nicnac said:

Kumho are good tyres .and relatively cheap . Go with these again is my recommendation . 

If you were going all 4 ...I am a big Michelin fan 

Michelin are good, but not for comfort... they are great for mileage in my experience, but they are very expensive, so perhaps not the best value. I would says PS4 are good for performance tyre outside of track tyres, but again they are not that comfortable. I had PS4 on my old IS250 and they were kind of overkill already, PS4s would be complete overkill and costing double the price than Dunlop RT2 or Goodyear Asymmetric 5... I just cannot see the benefits you getting from Michelin.

Kuhmo are ~OK... I would not throw them away if I get them when buying the car, but I would not get them myself... the that "relatively cheap is the reason"... for something like £5-8 more per tyre it is possible to find substantially better options... and for purchase like tyres which will last at very least 2-3 years £20-30 is negligible amount, for substantial difference.

Same could be said about many mid-range brands nowadays, say Uniroyal Rainsport 5 - excellent tyre all around, but currently they are price as such that you can get Goodyear Asymmetric 5 for the same price and sometimes few £ cheaper... and that tyre is just on another league. 

[nicnac]

5 minutes ago, Linas.P said:

Michelin are good, but not for comfort... they are great for mileage in my experience, but they are very expensive, so perhaps not the best value. I would says PS4 are good for performance tyre outside of track tyres, but again they are not that comfortable. I had PS4 on my old IS250 and they were kind of overkill already, PS4s would be complete overkill and costing double the price than Dunlop RT2 or Goodyear Asymmetric 5... I just cannot see the benefits you getting from Michelin. 

Michelin are one ofthe most comfortable tyres on the market . They have very supple walls..............so there Linas ...we disagree again ! ...........but hey he is going Kumho 😊😊😊😊

I JUST KNEW YOU WOULD HAVE AN ANGLE !!!!!!!!😂😂😂😂😂

[Linas.P]

11 minutes ago, nicnac said:

Michelin are one ofthe most comfortable tyres on the market .

but hey he is going Kumho 😊😊😊

That is just not true. They are reasonably comfortable for the performance they provide. PS4 and especially PS4s are one of the most capable UHP tyres there are. My last set of tyres was PS4... it was comfortable enough... but they are very long way from "most comfortable on the market". Like for like set before that were Dunlop RT's and they were more comfortable and that isn't even tyre known for comfort.

If I had IS350 I would probably put PS4 on it, or if I had IS-F would would put PS4s on it... but for IS250 I felt it was already in territory of diminishing returns - car is not powerful enough to need as much mechanical grip as PS4 can provide, but PS4 is already high performance tyre where it starts to feel it sacrifices comfort for grip an handling. In short PS4 were overkill for IS250 - more comfortable tyres can be had for less money and without sacrificing anything.

Tyres are always sacrifice - a lot of grip, means more wear... very comfortable, means vague steering... very soft, means higher fuel consumption. Best tyres are just compromise which has right balance of all these variables. Sure sometimes there are new rubber compound where all characteristics are improved at once, but mostly all premium tyres going to be very similar, just going to have slight different balance. I found that balance to be closest to my liking on Dunlop RT2 and I assume Goodyear Asymmetric 5 will be similar (Dunlop and Goodyear is the same company). Michelin PS4 and Continental Premium Contact would be more performance oriented + more expensive. PS4s and Sport Contact would yet another step further in higher and performance direction.

He is not going for Kuhmo - Kuhmo is already on the car. If they in any sort of decent shape it would be wasteful to replace perfectly good tyres.

[nicnac]

4 minutes ago, Linas.P said:

That is just not true. They are reasonably comfortable for the performance they provide. PS4 and especially PS4s are one of the most capable UHP tyres there are. My last set of tyres was PS4... it was comfortable enough... but they are very long way from "most comfortable on the market". Like for like set before that were Dunlop RT's and they were more comfortable and that isn't even tyre known for comfort.

If I had IS350 I would probably put PS4 on it, or if I had IS-F would would put PS4s on it... but for IS250 I felt it was already in territory of diminishing returns - car is not powerful enough to need as much mechanical grip as PS4 can provide, but PS4 is already high performance tyre where it starts to feel it sacrifices comfort for grip an handling. In short PS4 were overkill for IS250 - more comfortable tyres can be had for less money and without sacrificing anything.

He is not going for Kuhmo - Kuhmo is already on the car. If they in any sort of decent shape it would be wasteful to replace perfectly good tyres.

HE IS GOING KUMHO ................ for the rear which are worn to limits .................................. and............... You are wrong ...I have had more tyres in my 50+ years of motoring than you have had hot dinners ,.......so there ...................... my opinion and experience trumps you on this one .....................only saying .........

 

That is just not true.................where is the evidence ?its subjective !

[Mr Vlad]

Now now girls. Hugh just ignore linas and nicnac because they will fry your head big time. 

Oh I've just ordered 2 Bridgestone Turanza T005's rears for my car. Excellent reviews and £230 a pair fitted from Halfords with a 10% discount. 

[nicnac]

1 minute ago, Mr Vlad said:

Now now girls. Hugh just ignore linas and nicnac because they will fry your head big time. 

Oh I've just ordered 2 Bridgestone Turanza T005's rears for my car. Excellent reviews and £230 a pair fitted from Halfords with a 10% discount. 

Linas will be along to tell you that was the wrong choice !!!!!!!!!!!!!!!!!!!!!!🤣🤣🤣🤣🤣🤣

[Linas.P]

32 minutes ago, Mr Vlad said:

Oh I've just ordered 2 Bridgestone Turanza T005's rears for my car. Excellent reviews and £230 a pair fitted from Halfords with a 10% discount. 

Absolutely, terrible choice and advise thought. Dunlop Sportmaxx RT2s and Goodyear Asymmetric 5s are just two alternatives which both are cheaper and far better. I have never seen review where Brigestone Turanzas would be recommended or even in top 10. Almost literally any premium tyre would be better choice.

[Linas.P]

27 minutes ago, nicnac said:

Linas will be along to tell you that was the wrong choice !!!!!!!!!!!!!!!!!!!!!!🤣🤣🤣🤣🤣🤣

You bet I will! 

Besides if you think that you have to be respected for your age, then think again - being older does not make your right and respect does not grow with your age  - it is earned... So your world is just as good as you could provides sources for it, only using your age as a reason already diminishes whatever little respect there is. 

As for moderators closing the thread - it may happen, because you keep polluting threads with your endless posts about nothing. Like now - you basically arguing whenever Michelin is MOST comfortable tyre maker overall instead of just agreeing they are reasonably comfortable, without even being able to provide single specific model comparison. I can at least compare my experience on PS4 and RT on IS250, both of which are popular tyres and provide some feedback on how comfortable they are based on my experience on exact car. 

@Hugh R... It would make sense to fit Kuhmo to have all same tyres on the car, I always prefer that as car will act more predictably. However, depending of how worn the fronts are, maybe it would be better to replace all 4 tyres with something else. Dunlop RT2s as you mentioned is great choice, however I would remind that Dunlop and Goodyear is the same company. RTs were almost identical to Asymmetric 3s, RT2 were newer and better than Asymmetric 3, but Asymmetric 5 are never than RT2's. I don't know if Asymmetric 5s are better than RT2's, but they will certainly not going to be worse. So for balanced and good value UHP tyre I would choose either of those.

Yet for comfort I would go with something else entirely. Perhaps Goodyear Efficient Grip - they are one of the latest tyres from Goodyear and seems to beat Michelin Primacy 4 in both wear and comfort. Michelin Primacy 4 actually being solid second place here in non-UHP tyres, but Michelins are far more expensive.

Here may be a review which could answer your some of your questions (spoilers alerts Bridgestone Turanza T005 are second worse tyre in it's own category).

 

 

[nicnac]

3 minutes ago, Linas.P said:

You bet I will! 

Besides if you think that you have to be respected for your age, then think again - being older does not make your right and respect does not grow with your age  - it is earned... So your world is just as good as you could provides sources for it, only using your age as a reason already diminishes whatever little respect there is. 

As for moderators closing the thread - it may happen, because you keep polluting threads with your endless posts about nothing. Like now - you basically arguing whenever Michelin is MOST comfortable tyre maker overall instead of just agreeing they are reasonably comfortable, without even being able to provide single specific model comparison. I can at least compare my experience on PS4 and RT on IS250, both of which are popular tyres and provide some feedback on how comfortable they are based on my experience on exact car. 

@Hugh R... It would make sense to fit Kuhmo to have all same tyres on the car, I always prefer that as car will act more predictably. However, depending of how worn the fronts are, maybe it would be better to replace all 4 tyres with something else. Dunlop RT2s as you mentioned is great choice, however I would remind that Dunlop and Goodyear is the same company. RTs were almost identical to Asymmetric 3s, RT2 were newer and better than Asymmetric 3, but Asymmetric 5 are never than RT2's. I don't know if Asymmetric 5s are better than RT2's, but they will certainly not going to be worse. So for balanced and good value UHP tyre I would choose either of those.

Yet for comfort I would go with something else entirely. Perhaps Goodyear Efficient Grip - they are one of the latest tyres from Goodyear and seems to beat Michelin Primacy 4 in both wear and comfort. Michelin Primacy 4 actually being solid second place here in non-UHP tyres, but Michelins are far more expensive.

Here may be a review which could answer your some of your questions (spoilers alerts Bridgestone Turanza T005 are second worse tyre in it's own category).

 

 

and on and on and on!!!!!!! ................................. take a little Hubris pill and keep shuffling the money ......................its all you can do !!!!! 

[Hugh R]

1 hour ago, nicnac said:

but hey he is going Kumho

Not necessarily!  Very drawn to Goodyear 5's as sooner or later front will need to be replaced.

[nicnac]

2 minutes ago, Hugh R said:

Not necessarily!  Very drawn to Goodyear 5's as sooner or later front will need to be replaced.

Whatever suites .................... your car ...your choice ................enjoy !