Ride quality with 225/45-17 all around vs 225/45-17 front & 245/40-17 rear combo? (07 IS250)

[Bugster_MR2]

Hi

My 07 IS250 is running stock 17" wheels and 225/45-17 front & 245/40-17 rear combo. I have noticed the rear rims are half an inch wider.

My rears are worn out now, and needs to be replaced. It should be possible to downsize to 225/45-17 on the rears, as far as I know.

My questions:

Have any of you tried running 225/45-17 all around on stock rims?

How did it change the ride quality?

My reasons to downsize would be that there is a much bigger selection in 225/45-17s than 245/40, and maybe a little less noise from the narrower tires.

Thanks in advance.

Bug

[Linas.P]

Is it possible - yes absolutely. Lexus IS250 AWD comes with exactly same wheels and 225 all around from the factory and wheels are obviously identical. I had IS250 AWD and cannot say I have noticed any difference in terms of ride quality. It handled poorly and was not fuel efficient, but that was because it was AWD, not because of the tyres.

I had RWD car on 225/235 but not 225 all around. In fact my recent auction purchase has 225/235 as well and I am looking to replace them with 225 all around and maybe 20mm spacers in the rear when I get it running again. Note - standard sizes for RWD are 245/45R17, so somebody already fitted "wrong" tyre on your rear.

The only downsides I can see to this - rear tyres wears quicker, so by having 225/245 they wear more or less equal, I would even say 245 maybe outlasting 225 a bit. But having all around 225 will mean that you will have noticeably more wear on the rear. But there is silver lining - because all tyres will be same you will be able to rotate them, kind of negating the negative. Other consideration, your speedo would already be 5-10% over-reading, once you move to 225s in the rear this will add another 3%. The positives - you will get better fuel economy, especially on motorway. 

[H3XME]

1 hour ago, Bugster_MR2 said:

Hi

My 07 IS250 is running stock 17" wheels and 225/45-17 front & 245/40-17 rear combo. I have noticed the rear rims are half an inch wider.

My rears are worn out now, and needs to be replaced. It should be possible to downsize to 225/45-17 on the rears, as far as I know.

My questions:

Have any of you tried running 225/45-17 all around on stock rims?

How did it change the ride quality?

My reasons to downsize would be that there is a much bigger selection in 225/45-17s than 245/40, and maybe a little less noise from the narrower tires.

Thanks in advance.

Bug

Running 225s all around is better for MPGs and overall feel of the car. Feels slightly more lively as there's less rotational mass. I'd recommend square setup. Never had any issues with mine 225/40R18 all round 🙂

[KamD]

49 minutes ago, H3XME said:

Running 225s all around is better for MPGs and overall feel of the car. Feels slightly more lively as there's less rotational mass. I'd recommend square setup. Never had any issues with mine 225/40R18 all round 🙂

I would stick to the staggered setup myself tbh. 245 on all four corners worsens the front. 225 on all 4 corners worsens the ride stability cornering on wet roads and traction on cold mornings. (Then again once I'm off the motorway and on a twisty road I'm an idiot, so... yeah, don't judge me too harshly)

If you really must do it, I'd much rather go for 245s on all corners. 

And if sizes are to be altered I'd go 215 front 265 rear. Just my 2 cents

[H3XME]

1 hour ago, KamD said:

I would stick to the staggered setup myself tbh. 245 on all four corners worsens the front. 225 on all 4 corners worsens the ride stability cornering on wet roads and traction on cold mornings. (Then again once I'm off the motorway and on a twisty road I'm an idiot, so... yeah, don't judge me too harshly)

If you really must do it, I'd much rather go for 245s on all corners. 

And if sizes are to be altered I'd go 215 front 265 rear. Just my 2 cents

Get good tyres and not ditch finders. This car doesn't have enough power to justify 245s. It's more lively on 225s in all 4 corners and you will never get an accidental over steer in this car. Not with stock suspension anyway. I've been using Toyo Proxes TR1 (previously T1R) for years now and they are mediocre tyres, but they're perfect for the IS250 imo. They suit me. On the GT86 in the exact same spec, they're so so if you're after grip, but that's because it's almost a 400kg lighter car. If you want a really good road tyre, Michelin PS4/PS5 is the way to go, but bear in mind that there is absolutely zero need to over compensate with width and kill any sort of feedback from the car when you can be on GOOD 225s. 

[MrTrendizzle]

I personally stepped down all the tyres.  

Front 205/45/17  

Rear 225/45/17  

Mainly due to cost. Ride is the same as before just the width has changed meaning less grip in the wet but the car dosn't feel unstable unless you're at very high speeds (110mph+ not on public roads)  

I buy my tyres online and fit them myself. Brand new tyres i can pick up for £38+ so less than £200 for a full set. Balancing i've never had an issue but if a wheel feels off to you just run it to your local garage and get them to chuck it on the machine for £5. The old tyre's can be taken to your local tip free of charge (Maximum of 4 per day/trip)

[Bugster_MR2]

Thanks for your input, guys. I am going try a square setup with 225/45-17 all around! I am sure it will make it feel a little more nimble with narrower tires in the rear.

[KamD]

18 minutes ago, H3XME said:

Get good tyres and not ditch finders. This car doesn't have enough power to justify 245s. It's more lively on 225s in all 4 corners and you will never get an accidental over steer in this car. Not with stock suspension anyway. I've been using Toyo Proxes TR1 (previously T1R) for years now and they are mediocre tyres, but they're perfect for the IS250 imo. They suit me. On the GT86 in the exact same spec, they're so so if you're after grip, but that's because it's almost a 400kg lighter car. If you want a really good road tyre, Michelin PS4/PS5 is the way to go, but bear in mind that there is absolutely zero need to over compensate with width and kill any sort of feedback from the car when you can be on GOOD 225s. 

There 2 things I never compromise on - tyres and brakes, you know... the things that keep you on the road. Personally don't like the Michelins, they're at best numb and wear too quickly. Running Goodyear Eagle 3s(slightly better than the 5s for whatever reason), 225/40/18 front, 265/40/18 rear. I don't know why people keep saying the IS250 is underpowered... On the roads I'm driving can pretty much make it misbehave in any gear at any speed... ( the Middlands, many farms about, lots of twisties) And from a stand still it's only a matter of flooring it to turn some rubber into smoke. Again, this is me... Can't speak for everyone.

The real strength of the 2IS is in the middle, on a kickdown. I tend to drive a lot in "manual" (not a manual at all... biggest downside of an automatic one) and with no traction control. I like driving. Can't justify buying it an LSD yet from GT86/Subaru BRZ, but I'm arguing it's merit and slowly convincing myself to get one. 

Tyres... would always overkill those, for as long as I can afford them. 

 

[H3XME]

38 minutes ago, KamD said:

 225/40/18 front, 265/40/18 rear. I don't know why people keep saying the IS250 is underpowered... On the roads I'm driving can pretty much make it misbehave in any gear at any speed... ( the Middlands, many farms about, lots of twisties) And from a stand still it's only a matter of flooring it to turn some rubber into smoke. Again, this is me... Can't speak for everyone.

 🤣  🤣 

45 minutes ago, KamD said:

Tyres... would always overkill those, for as long as I can afford them. 

But why? You're killing the car. The characteristics, the feel, mpgs, tiring the engine too as it needs to work harder to spin those fat tyres.. and for what?  Tyres can only do so much, and if you over-tyre your car, it will perform worse. I have no doubt your car will be understeer-y when pushed now because of such a big tyre difference on your car. 

[KamD]

12 minutes ago, H3XME said:

 🤣  🤣 

But why? You're killing the car. The characteristics, the feel, mpgs, tiring the engine too as it needs to work harder to spin those fat tyres.. and for what?  Tyres can only do so much, and if you over-tyre your car, it will perform worse. I have no doubt your car will be understeer-y when pushed now because of such a big tyre difference on your car. 

So, 10mm wider is worse than 30mm narrower tyre? 🤔 Don't follow that logic at all! Please clarify how upsizing by 10mm (OEM 18s are 255 🤷‍♂️) is worse than downsizing by 30mm . 

Also don't understand why you're laughing at my one wheel peels (which I hate btw... ). With an LSD the IS becomes wildely underpowered (friend of mine has it fitted on his, takes a fair bit to make it loose it's tail) with the OEM open diff you're literally a mash away from making it spin a wheel, and if you don't let go that wheel starts smoking rather quick, when VSC off 🤷‍♂️ 

2IS has a choppy suspension on the back - 265/40/18 is a very very comfortable tyre on it and doesn't make virtually no difference at all to the MPG. 

It's a 2.5 V6 lazy and understressed engine that can do much better when booted. 

Feel free to correct me on any point if I'm wrong. 

[Linas.P]

1 hour ago, KamD said:

There 2 things I never compromise on - tyres and brakes, you know... the things that keep you on the road. Personally don't like the Michelins, they're at best numb and wear too quickly. Running Goodyear Eagle 3s(slightly better than the 5s for whatever reason), 225/40/18 front, 265/40/18 rear. I don't know why people keep saying the IS250 is underpowered... On the roads I'm driving can pretty much make it misbehave in any gear at any speed... ( the Middlands, many farms about, lots of twisties) And from a stand still it's only a matter of flooring it to turn some rubber into smoke. Again, this is me... Can't speak for everyone.

The real strength of the 2IS is in the middle, on a kickdown. I tend to drive a lot in "manual" (not a manual at all... biggest downside of an automatic one) and with no traction control. I like driving. Can't justify buying it an LSD yet from GT86/Subaru BRZ, but I'm arguing it's merit and slowly convincing myself to get one. 

Tyres... would always overkill those, for as long as I can afford them. 

I agree that tyres is like literally the only thing which matters when it comes to safety, but just putting widest rubber possible on any car isn't the solution. Narrower tyres are actually better for aquaplaning and wet, where wide tyres matters are only dry grip, but I can't see how 208HP justifies 265 in the rear. On top of that narrower tyres better on noise and economy. Comfort more depends on specific tyre you have, some are more comfortable - I was quite happy with Dunlops RT2s and Pirelli P-Zeros, but Michelin PS4 were noticeably less comfortable. I know that Goodyear Asymetric 3/5s are quite good as well. 

Michelins wear too quickly... really? wear is like their main strength. What Michelins were you using? I had PS4 on IS250 when I had mk3 18" F-Sport wheels on mine and I felt like I can't get them-up to temp. mechanical grip was there but they never felt like compound is gripping to really push it. At best the tyres would feel right by the time I am 10 minutes away from home on ~45min drive. I had 225/245 on mine, so that was 10mm narrower than spec. in the rear. But they lasted forever - I think it was 5.5mm left after 30k miles.

In my experience IS250 is just barely adequate when it comes to power (I guess for it's time it was ok), one thing which is good at is that it sounds nice and the further you push it the happier it is. It just like to be revved-out, however what has always bothered me on the car was the unnatural balance in the corners, Lexus made it "safe" to handle with those wider rear wheels, meaning that at any time you push it in the corner it just understeers and keeps understeering, almost like FWD. So going few sizes down in the rear was always my plan, with square set-up car just feel more natural like RWD car should feel and more predictable. Now again - I have not had 225 all around on RWD, but I had 225/235R17 and I had 225/245R18, which was definitely step in right direction... and the only way to further improve it would be going square 225s or square 235s.

 

[H3XME]

17 minutes ago, KamD said:

So, 10mm wider is worse than 30mm narrower tyre? 🤔 Don't follow that logic at all! Please clarify how upsizing by 10mm (OEM 18s are 255 🤷‍♂️) is worse than downsizing by 30mm . 

Yes. What's the need to use a wider setup than a 420hp IS-F?? IS-Fs have 255s on the back.. You're using 265s in a car with half the power. See where I'm going with this? 

IS250 wasn't their "performance" model. This platform was made with IS300, 350 & IS-F in mind. A lot of things are shared across the models, so of course this car with "base/entry level" engine option is going to have things that can be found on other models. Manufacturers do this to save money. Stock 18s on IS250 come with 255s because they are using 8.5J rims that are also on the more powerful IS300 and IS350 that will actually benefit from bigger tyres given the power. Not to mention, all of this is dating back to 2005.. tyre technology has evolved. This is why 2014 (MK3) IS250 was sold on 225s all round - tyres are better and 255s is an overkill today on a 250.. 

33 minutes ago, KamD said:

Also don't understand why you're laughing at my one wheel peels (which I hate btw... ). With an LSD the IS becomes wildely underpowered (friend of mine has it fitted on his, takes a fair bit to make it loose it's tail) with the OEM open diff you're literally a mash away from making it spin a wheel, and if you don't let go that wheel starts smoking rather quick, when VSC off 🤷‍♂️ 

I have an LSD in mine. I know what the car is like. I did drift days and a lot of Wales trips in it too. I know how it drives and how it behaves. You said yourself earlier that you "don't know why people keep saying the IS250 is underpowered... On the roads I'm driving can pretty much make it misbehave in any gear at any speed..." which I find hard to believe, even with an open diff.

 

[H3XME]

3 minutes ago, Linas.P said:

I agree that tyres is like literally the only thing which matters when it comes to safety, but just putting widest rubber possible on any car isn't the solution. Narrower tyres are actually better for aquaplaning and wet, where wide tyres matters are only dry grip, but I can't see how 208HP justifies 265 in the rear. On top of that narrower tyres better on noise and economy. Comfort more depends on specific tyre you have, some are more comfortable - I was quite happy with Dunlops RT2s and Pirelli P-Zeros, but Michelin PS4 were noticeably less comfortable. I know that Goodyear Asymetric 3/5s are quite good as well. 

Michelins wear too quickly... really? wear is like their main strength. What Michelins were you using? I had PS4 on IS250 when I had mk3 18" F-Sport wheels on mine and I felt like I can't get them-up to temp. mechanical grip was there but they never felt like compound is gripping to really push it. At best the tyres would feel right by the time I am 10 minutes away from home on ~45min drive. I had 225/245 on mine, so that was 10mm narrower than spec. in the rear. But they lasted forever - I think it was 5.5mm left after 30k miles.

In my experience IS250 is just barely adequate when it comes to power (I guess for it's time it was ok), one thing which is good at is that it sounds nice and the further you push it the happier it is. It just like to be revved-out, however what has always bothered me on the car was the unnatural balance in the corners, Lexus made it "safe" to handle with those wider rear wheels, meaning that at any time you push it in the corner it just understeers and keeps understeering, almost like FWD. So going few sizes down in the rear was always my plan, with square set-up car just feel more natural like RWD car should feel and more predictable. Now again - I have not had 225 all around on RWD, but I had 225/235R17 and I had 225/245R18, which was definitely step in right direction... and the only way to further improve it would be going square 225s or square 235s.

I agree with pretty much everything you said. As for the PS4s are getting them up to temp. Never had the issue, BUT I never had them on this car. 

 

6 minutes ago, Linas.P said:

In my experience IS250 is just barely adequate when it comes to power (I guess for it's time it was ok), one thing which is good at is that it sounds nice and the further you push it the happier it is. It just like to be revved-out, however what has always bothered me on the car was the unnatural balance in the corners, Lexus made it "safe" to handle with those wider rear wheels, meaning that at any time you push it in the corner it just understeers and keeps understeering, almost like FWD. So going few sizes down in the rear was always my plan, with square set-up car just feel more natural like RWD car should feel and more predictable. Now again - I have not had 225 all around on RWD, but I had 225/235R17 and I had 225/245R18, which was definitely step in right direction... and the only way to further improve it would be going square 225s or square 235s.

Exactly what I highlighted. Nobody, who knows how a RWD car should drive, and likes driving, would put 265s on the back of this car for "spirited drive" purposes. I'd stick with the 255s only if you're worried that your wife who's never driven a RWD car would have an accident in the rain. This will keep her safe, but it's definitely not the way to drive if you're into "performance" or "sporty" driving on the back roads. It's like operating a steam roller. 

Yes Linas, 225s all round on RWD 200hp works amazing, even on this heavy IS250, it's more lively, it's nimble, gives you more feedback and mainly it's more predictable. You feel the road. Fat tyres completely kill the connection, I know that because my car wasn't always on 225s.. 

 

[Linas.P]

5 minutes ago, H3XME said:

I'd stick with the 255s only if you're worried that your wife who's never driven a RWD car would have an accident in the rain.

And even then only if she finds out how to disable TC.

As for Michelins temp - maybe I am exaggerating a bit, but you know the feeling when you get out on the cold morning and tyres are cold and just doesn't feel like you have all grip available. Then after few miles they feel like they have "warmed-up". So with Michelins this feeling would take much longer to get compared directly to Dunlop Sportmaxx RT2 which I had right before them. They still had plenty grip, but never had that confidence inspiring feedback... maybe it was just me but I felt like the tyre could act unpredictably for quite a while. 

[H3XME]

1 minute ago, Linas.P said:

And even then only if she finds out how to disable TC.

As for Michelins temp - maybe I am exaggerating a bit, but you know the feeling when you get out on the cold morning and tyres are cold and just doesn't feel like you have all grip available. Then after few miles they feel like they have "warmed-up". So with Michelins this feeling would take much longer to get compared directly to Dunlop Sportmaxx RT2 which I had right before them. They still had plenty grip, but never had that confidence inspiring feedback... maybe it was just me but I felt like the tyre could act unpredictably for quite a while. 

Tyres are a really funny topic because 10 people will say 10 different things. Chances also are that those 10 people will have 10 different driving styles and habits and it's hard to make an opinion without trying some. It's definitely down to your personal preference at the end of the day. My Proxes TR1 may not suit you and your driving style, but are perfect for me and vice versa. I remember someone had a go at me when I was "Reviewing" the RC300h for justifying my opinion.. this is exactly why it's important to justify it. With stuff like tyres, you need to be specific about how you drive and what you do with the car to validate anything. If let someone randomly drive my car on track tyres, they would say they're awful, but it's all very dependant on conditions.

[KamD]

Yall drive whatever tyres you like... fit plastic covers on them to make it even more happy at the business end. 

Pilot sport 4s, Linas. 

As for the rest... I suppose a pointless argument at this point. 

So we have wide tyres in high performance cars to keep them on the road, especially in wet, but because the 2IS is only 208 we can put it on w9od blocks and it'll be fine - very sound logic! (Farm roads means a lot of dust and slippery muddiness of different denomination 4 seasons round... )

Yall have fun and stay safe, alright? 

[Linas.P]

Yeah - agreed. I was definitely not tracking my car and not drifting in it or doing burnouts, but I would say I drive it very hard all the time as much as it is possible on public road without being completely silly (I am sure I would have long lost my license in any other country).

It is possible to get IS250 misbehave if you deliberately trying, I remember once I was driving without TC on N500, got to the petrol station in the evening and realised it is closed, kind of got my annoyed and on exit I floored it into nice bend, kind of forgotten TC was off and it was very wet and still cold early spring... and car was spinning wheels all the way into 3rd/60-70MPH. So yes it could be done if you trying, but IS250 definitely does not actively trying to kill anyone and even then it is hard to do it once you already at speed, because if you on staggered set-up, no matter what you do the front will lose grip before the rear and car is kind of unpredictable that way. I never really tried to drift it with AT box, so never really got to setting it-up, but form whatever occasional slip-ups I had the car felt unpredictable on staggered set-up, too little grip in the front and too much in the rear, so it was always a risk to push the front away or overcorrect it. 

[H3XME]

4 minutes ago, KamD said:

 but because the 2IS is only 208 we can put it on w9od blocks and it'll be fine 

Don't be salty because we tried to educate you on the subject. Forum is a source of knowledge & experience. You're not expected to know everything, so learn from people who do. There is always gonna be someone who knows more than you, me and the next person. 

[Linas.P]

11 minutes ago, KamD said:

Pilot sport 4s, Linas. 

So we have wide tyres in high performance cars to keep them on the road, especially in wet, but because the 2IS is only 208 we can put it on w9od blocks and it'll be fine - very sound logic!

Maybe PS4s then wear more than PS4, who knows... 

NO - wider tyres are especially for DRY grip. Wider tyre is more likely to aquaplane, the more surface of the tyre touches the road, the less pressure it has, so the less water it could push out. Nobody says to put wood block on the car, but 208hp just does not justify fitting such wide tyres, because modern/premium 225s are more than capable to handle this power. But on the dry yes - it is kind of simple, the wider is the tyre the better.

Maybe your issue with grips is that you fitted TOO WIDE tyres and that is why you can't get any grip in the WET? 

[H3XME]

21 minutes ago, Linas.P said:

the car felt unpredictable on staggered set-up, too little grip in the front and too much in the rear, so it was always a risk to push the front away or overcorrect it. 

Yeah, this is where fun becomes dangerous. You want drive harder but the car isn't letting you. It's always better to be that way because you're aware of your car's limits and your own limits. I'd much rather oversteer because I'm more comfortable and experienced with correcting that as opposed to understeer where there is very little for you to do.

[H3XME]

3 minutes ago, Linas.P said:

Maybe your issue with grips is that you fitted TOO WIDE tyres and that is why you can't get any grip in the WET? 

Following this logic will work eventually. Keep going wider and wider, get to 385s and you won't lose grip in the wet because your 200hp IS250 will struggle to spin the wheels at all, let alone break the traction 🤣

[Linas.P]

1 minute ago, H3XME said:

Yeah, this is where fun becomes dangerous. You want drive harder but the car isn't letting you. It's always better to be that way because you're aware of your car's limits and your own limits. I'd much rather oversteer because I'm more comfortable and experienced with correct that than understeer which there is very little for you to do.

As well, this is why many considers BRZ/GT86 such a good beginner car, skinny tyres simply don't have enough grip to allow you to reach the speeds at which you can be in trouble and it is balanced nicely without any silly "safe handling". So it let's you to get to tyre limits at safe speed, where you can still ride on that limit.

[H3XME]

2 minutes ago, Linas.P said:

As well, this is why many considers BRZ/GT86 such a good beginner car, skinny tyres simply don't have enough grip to allow you to reach the speeds at which you can be in trouble and it is balanced nicely without any silly "safe handling". So it let's you to get to tyre limits at safe speed, where you can still ride on that limit.

It is a great car that is forgiving, but experienced drivers will have a lot of fun in it too. Stock 215/45R17 tyres are awful on that car. They're Michelin Primacy (same tyre as on Prius) and the car is almost dangerous on them, especially on cold/wet days. However, running those tyres in combination with "aggressive" driving will gradually make you faster. You will learn how to take better lines, you will learn how to brake, you will learn how to correct over steer, how to avoid oversteer (and not just by going slow).. all that because the tyres are horrendous but at the same time a brilliant learning tool. You will learn the limit of your car (well..its tyres), and when you step up to better tyres and better brakes, you can keep pushing and the car will be a lot faster because you will be faster. Anyway.. I'd highly recommend it because at the end of the day it makes you a better driver. 

[KamD]

44 minutes ago, H3XME said:

Don't be salty because we tried to educate you on the subject. Forum is a source of knowledge & experience. You're not expected to know everything, so learn from people who do. There is always gonna be someone who knows more than you, me and the next person. 

I'm not salty, and you're not educating me, my friends..  Don't make ME, educate YOU, please... Just be safe 🤭

[H3XME]

2 minutes ago, KamD said:

Just be safe 🤭

I will be, I'm not understeering my way into a ditch on 225/265 combo 😂