18 vs 19 inch sound and comfort difference on 245/45 or 245/40
05-08-19, 08:29 AM
#1
Intermediate
Thread Starter
18 vs 19 inch sound and comfort difference on 245/45 or 245/40
For almost a year I am really in doubt with this. I thought I made my decision to go for 18 (On 245/45 R18) but every time when I see an LS on 19 I am convinced that this looks 10 times better but still comfort and most of all "silence" is the very most important to me.
I already tried to contact Dunlop for this because I am driving now on the 245/45/18 with NST (Noise Shield Technologie) and I told them about my question. Do I lose lots of comfort and do I get more roadnoise when I keep almost the same size, only an Inch bigger for example 245/40 r19?
To be exact. I was already searching google with this size comparing question way before I owned this Lexus.
I think Dunlop didnt even understand my question correctly and they only said: In our list the 19 inch are even 1 or 2 db lower so they are even more quit.
Thank you Dunlop! But I can find those figures myself on the internet after a few years of research. I want to know what I am going to lose in comfort because of, maybe WAY more stiffer sidewalls? And how about an extra drone what coudnt be measured in db? Thats why I contacted the creators of this. No answer.
Now I am even thinking. How about 245/45 R19. Not available with Dunlop but Michelin does have them with the same Foam technologie (Primacy Acoustic 775901). The difference is that Michelin’s are 69 and the Dunlop 245/40 R19 are 68db
How about you guys? Whats your opinion on this question?
I dont know If you have Dunlop in the US but It seems that its the same company as Goodyear and their Silent Foam tyres should be pretty much the same.
I already tried to contact Dunlop for this because I am driving now on the 245/45/18 with NST (Noise Shield Technologie) and I told them about my question. Do I lose lots of comfort and do I get more roadnoise when I keep almost the same size, only an Inch bigger for example 245/40 r19?
To be exact. I was already searching google with this size comparing question way before I owned this Lexus.
I think Dunlop didnt even understand my question correctly and they only said: In our list the 19 inch are even 1 or 2 db lower so they are even more quit.
Thank you Dunlop! But I can find those figures myself on the internet after a few years of research. I want to know what I am going to lose in comfort because of, maybe WAY more stiffer sidewalls? And how about an extra drone what coudnt be measured in db? Thats why I contacted the creators of this. No answer.
Now I am even thinking. How about 245/45 R19. Not available with Dunlop but Michelin does have them with the same Foam technologie (Primacy Acoustic 775901). The difference is that Michelin’s are 69 and the Dunlop 245/40 R19 are 68db
How about you guys? Whats your opinion on this question?
I dont know If you have Dunlop in the US but It seems that its the same company as Goodyear and their Silent Foam tyres should be pretty much the same.
05-08-19, 10:05 AM
#4
Lexus Champion
You don't really expect tire manufacturers to test tires and determine the effect on noise for every car, every model, do you? It is even more unlikely that they would test off-sizes from the car manufacturers requirement. I would guess that 99.9% of the people who buy new tires for their cars specify what came on the cars when they bought them.
05-08-19, 12:17 PM
#5
Intermediate
Thread Starter
You don't really expect tire manufacturers to test tires and determine the effect on noise for every car, every model, do you? It is even more unlikely that they would test off-sizes from the car manufacturers requirement. I would guess that 99.9% of the people who buy new tires for their cars specify what came on the cars when they bought them.
No definitely not! And thats not the question. The question is the difference between 18 and 19 inch on a mid size or big size car. The specs they give on each tyre is also not specific to a car so they should give me an answer on this to.
Again I am talking about the same width 245 and even the same hight and that could even result in a better and more smooth ride because the total hight is bigger so the rpm's goes down.
My experience with tyres are, the higher the side wall and the bigger the total hight, the better it drives. To make a total different comparing. My gs300 is sitting now on 225-65 R16 wile 55 is original but with 55 the engine is making way more rpm's on the highway. I hate that stock size.
There will be no definitive answer on this, since a change in tire size could also mean a change in wheel mass, a change in tire construction, a change in tire pressure, a change in steering geometry, a change in tread design, and/or a change in tire mass. So lots of variables that could affect noise, vibration, and harshness. Also, the very subjective nature of how sensitive you might be to any changes. It isn't just as simple as a numerical change from 18 to 19.
All that said, if I were in your shoes and wanted to upsize the wheels, I'd try to assemble the lightest, softest riding tire on the lightest wheel you can find that has a similar width and offset as stock. Buy them and install them with the understanding you may hate the combination and have to turn around and sell them. You'd be out several hundred bucks, but at least you'd know.
If you can accept that risk, you'll be fine. If not, then maybe just learn to love the 18s and find something else to obsess over. :-)
I have factory 19s on one of my other non-Lexus cars. They look like hot buttered sex, but I hate the way they ride. I don't hate them enough to swap though.
All that said, if I were in your shoes and wanted to upsize the wheels, I'd try to assemble the lightest, softest riding tire on the lightest wheel you can find that has a similar width and offset as stock. Buy them and install them with the understanding you may hate the combination and have to turn around and sell them. You'd be out several hundred bucks, but at least you'd know.
If you can accept that risk, you'll be fine. If not, then maybe just learn to love the 18s and find something else to obsess over. :-)
I have factory 19s on one of my other non-Lexus cars. They look like hot buttered sex, but I hate the way they ride. I don't hate them enough to swap though.
This is really interesting. What Lexus do you drive yourself with the 19 and what are the sizes and brand? And what do you exactly hate?
Smart about thinking of the weight too but I really want the Work Eurolines in the back with a very deep dish and still keep that 245.
I also putted lots of sound proofing in the car. Stage 2 of that will be coming soon and that will be the wheel arches on the outside and putting that stuff all over the place down there! (planning to make a Rolls Royce killer with that)
05-08-19, 07:20 PM
#6
Racer
I nought mine with 18s and sold them to have 17s. The ride is smoother and more comfortable, just the way I like it.
Any 19s you buy may look better .... but they won't ride as smooth and quiet.
05-09-19, 12:48 AM
#7
Intermediate
Thread Starter
Ah, if you take another look above, I said "non-Lexus" ;-) I don't have a Lexus on 19s. It's a Porsche. I Ihink 19s have a place on a sports car. Just not sure I could tolerate them on my LS430 though. I wish there were some good-looking OEM 17s I could swap onto the LS, but I haven't discovered any yet.
I,m happy I opened this topic because I am right now more hanging to the 18's....
The LS is also for me the sunday and holidaycar and when I am arriving at some nice places in the south of France I can be proud at the level of comfort when I am driving between some Rolls Royces and Bentleys.
Last edited by NLLex; 05-09-19 at 12:51 AM.
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05-09-19, 05:40 AM
#8
My '06 430 is smooth as butter on the stock 18s. I can't see needing more comfort than I have already.
05-09-19, 11:55 AM
#10
Lexus Fanatic
If width is the same, I prefer less rim, more sidewall, down to 18. Oddly 17's look tiny in this day and age.
It's always been my opinion that vehicles who offer different rims such as 18, 19, 20, from the factory, if the width is the same, I go with the smallest. But when you say 225/50-17 or 245/45-18, I'm going to choose the latter in the summer. If winter, yes, the former. Why would you want a 245 19, over a 245 18? You've got 1" less sidewall, same width, and more unsprung weight. A trifecta of negatives.
It's always been my opinion that vehicles who offer different rims such as 18, 19, 20, from the factory, if the width is the same, I go with the smallest. But when you say 225/50-17 or 245/45-18, I'm going to choose the latter in the summer. If winter, yes, the former. Why would you want a 245 19, over a 245 18? You've got 1" less sidewall, same width, and more unsprung weight. A trifecta of negatives.
05-09-19, 01:21 PM
#11
Intermediate
Thread Starter
I want to keep that comfort on 19's.....
If width is the same, I prefer less rim, more sidewall, down to 18. Oddly 17's look tiny in this day and age.
It's always been my opinion that vehicles who offer different rims such as 18, 19, 20, from the factory, if the width is the same, I go with the smallest. But when you say 225/50-17 or 245/45-18, I'm going to choose the latter in the summer. If winter, yes, the former. Why would you want a 245 19, over a 245 18? You've got 1" less sidewall, same width, and more unsprung weight. A trifecta of negatives.
It's always been my opinion that vehicles who offer different rims such as 18, 19, 20, from the factory, if the width is the same, I go with the smallest. But when you say 225/50-17 or 245/45-18, I'm going to choose the latter in the summer. If winter, yes, the former. Why would you want a 245 19, over a 245 18? You've got 1" less sidewall, same width, and more unsprung weight. A trifecta of negatives.
I never drive in the winter because its my showcar and It must be kept in the best condition. I am going to need more info about that unsprung weight and how that effects the ride exactly.... never really thought about that before I opened this topic.
05-09-19, 02:19 PM
#12
Intermediate
Suspension is not very intuitive. Our backside tells us the suspension is all about movement of the body of the car, and that's not really how it works.
Unsprung weight is exactly what the term says. It's those parts of the car that the suspension parts do NOT support. The suspension is all about the tires and wheels. It is the weight of the suspension components that is significant.
The spring soaks up the movement, the shocks or dampers slow or dampen the motion of the springs. What is important is the weight of the components that the springs and dampers support.
This is why high end cars like the LS use Aluminum rather than steel for heavy suspension components.
Suspension is all about controlling the motion of the wheels. When we make the wheels heavier it increases the amount of work the suspension must do. One of the greatest car designers was Colin Chapman, of Lotus fame. His famous quote. Add lightness.
Unsprung weight is exactly what the term says. It's those parts of the car that the suspension parts do NOT support. The suspension is all about the tires and wheels. It is the weight of the suspension components that is significant.
The spring soaks up the movement, the shocks or dampers slow or dampen the motion of the springs. What is important is the weight of the components that the springs and dampers support.
This is why high end cars like the LS use Aluminum rather than steel for heavy suspension components.
Suspension is all about controlling the motion of the wheels. When we make the wheels heavier it increases the amount of work the suspension must do. One of the greatest car designers was Colin Chapman, of Lotus fame. His famous quote. Add lightness.
05-09-19, 05:25 PM
#13
My 20s are 3 pounds heavier than the OEM 18s without tires. The lower profile tires vs stock cut down about a pound so I'm around 2 pounds more per corner over a stock 18, I think that's about the margin if error I could expect just from switching tire brands
05-10-19, 06:44 AM
#14
Lexus Fanatic
Suspension is not very intuitive. Our backside tells us the suspension is all about movement of the body of the car, and that's not really how it works.
Unsprung weight is exactly what the term says. It's those parts of the car that the suspension parts do NOT support. The suspension is all about the tires and wheels. It is the weight of the suspension components that is significant.
The spring soaks up the movement, the shocks or dampers slow or dampen the motion of the springs. What is important is the weight of the components that the springs and dampers support.
This is why high end cars like the LS use Aluminum rather than steel for heavy suspension components.
Suspension is all about controlling the motion of the wheels. When we make the wheels heavier it increases the amount of work the suspension must do. One of the greatest car designers was Colin Chapman, of Lotus fame. His famous quote. Add lightness.
Unsprung weight is exactly what the term says. It's those parts of the car that the suspension parts do NOT support. The suspension is all about the tires and wheels. It is the weight of the suspension components that is significant.
The spring soaks up the movement, the shocks or dampers slow or dampen the motion of the springs. What is important is the weight of the components that the springs and dampers support.
This is why high end cars like the LS use Aluminum rather than steel for heavy suspension components.
Suspension is all about controlling the motion of the wheels. When we make the wheels heavier it increases the amount of work the suspension must do. One of the greatest car designers was Colin Chapman, of Lotus fame. His famous quote. Add lightness.
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