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Request for Ride Quality Experience 19 inch vs 18 inch
Thinking about going to 19 inch wheels, non-staggered using 19 inch x 8 inch wheels. However, I'm a little leary about the sidewall decrease from 245/40/18 tires to 245/35/19 tires. I'm on Pilot Sports and definitely will not be using run-flats. Looked through some wheel threads here, but most of commentary is about how larger wheels look, not how they feel or perform.
I'm itching to make the change after seeing the RC350 wheels a couple owners have mounted. The main difference I'm planning is non-staggered so I an continue with front/back rotations.
What summer tires and how does the SC430 feel changing from 18 to 19 inch rims?
Here's a mockup. The look is the right balance for my taste, but it's a sickness ---- wanting to change the looks, but risking ride quality. However, looks are useless if the daily ride becomes awful.
Cars ride quality was marginal. Took 45 series tires and coilovers to ride ok on 18’s
Thanks. This is the type of ride info I'm after.
I take this to mean that you found the ride was marginal on 19 inch rims, and you had to go to 18 inch with 45 ratio to get a good ride feel? Your feedback is particularly interesting because our suspensions are similar style setup.
I went from 40 series 18’s to 45 series 18’s. Helped noticeably on ride quality. The idea of going to 19’s in 35 series and even mentioning ride quality would seem to be a non starter.
But you are seeming to be looking for an confirmation that a lower profile tire is not going to ride worse.
a few owners have switched to 17” rims and higher number series tires to improve their ride quality.
45/18’s AND Meister coilovers set full soft now ride smoother.
No way IMO that 19/35’s would not have a fairly poor ride.
several 20’” posters here complain about the ride quality.
I almost went to 17’s. But the 45’s and the softer coilovers fixed it.
If they fit without rubbing I would stick with 40 sidewall even with 19’s. 45 non run flats vs 40 run flats on my stock 18’s was a pretty major difference.
I was expecting to hear that the 19's were going to be an issue in 35 series. You confirm that fear. I'm currently happy with the ride on the OEM size 245-40-18, but getting much stiffer would be iffy, particularly with my new, stiffer suspension.
One other possibility I ponder is 235-40-19 like the fronts of the RC350. It would be a slightly larger diameter but a tad narrower.
Narrowing by 10 mm, I can deal with. My winter setup is definitely narrower and softer sidewalled .... 225/55 R16's on 7 inch wide rims. Those definitely feel a bit smoother than my summer setup, although not as grippy and stable.
235-40-19 would put me about 2.7% larger diameter than stock and 5% less sidewall height compared to OEM.
Your 245/45/18 are 3.9% larger diameter and 10% more sidewall height compared to OEM.
BTW any clearance or startup torque issues with your 245/45/18 tires? That is nearly identical in size to 245/40/19, which would also be possible candidate.
Maybe Touren 3260's in 18 inch x 8 will be the answer to get a similar look, without altering my ride characteristics.
I'm due to replace my summer tires this year, and what better time to also make rim size changes to and get new tires that match. If I just get new tires, I'm locked into the same rim size for another three years. Hence, my explorations now.
Last edited by Seattle SCone; 02-07-21 at 07:54 PM.
Hi , I have just fitted 245 /45/18 ,I found that going from the 40 to 45 has made a big difference comfort wise, I also have the tires filled with nitrogen ,which I think adds to quality of ride .
Hi , I have just fitted 245 /45/18 ,I found that going from the 40 to 45 has made a big difference comfort wise, I also have the tires filled with nitrogen ,which I think adds to quality of ride .
Air is 78% nitrogen. Please explain the physics behind how that would have any effect on ride quality. And yes, I do understand the expansion contraction qualities of the two gases.
I bought my SC with 19 inch tires. The ride quality was terrible. When I went into the dealer for the airbag recall, he said it was the bigger rims size and the shorter tires fault.
I bought some updated and 18 inch rims from an IS350. I expected a much nicer ride. I only got a slightly better ride. This makes me think it is a strut/suspension issue and/or the tires on the IS are more sporty than what should be on the SC. So I did the opposite of what you are considering and was not impressed with the results.
On a side note...
It was interesting when you drive into the Lexus service lane, they have a camera built into the floor to look at your tire tread.
DshngDaryl, do you recall what the tire sizes were on your 19's?
I also found stock suspension is worst of both worlds (harsh + boat like waddling) with 18 inch OEM wheels and non-flats. With run-flats, the SC430 is basically an unpredictably straying beast as it tram rails with any rut. Non-runflats solve the tram lining, but not the worst of both worlds suspension. After sway bars and coilovers, the suspension is finally decently sporty and stable with appropriate level of road contact feel for a GT. That's with 18 inch rims.
My quandary is whether 19 inch rims + 40 series tires will still be a good ride. I think we've pretty much answered that 35 series on 19 inch rims is bad idea.
Air is 78% nitrogen. Please explain the physics behind how that would have any effect on ride quality. And yes, I do understand the expansion contraction qualities of the two gases.
The only benefit to nitrogen is the expansion / contraction qualities. Otherwise it is a gimmick / waste of money.
DshngDaryl, do you recall what the tire sizes were on your 19's?
I also found stock suspension is worst of both worlds (harsh + boat like waddling) with 18 inch OEM wheels and non-flats. With run-flats, the SC430 is basically an unpredictably straying beast as it tram rails with any rut. Non-runflats solve the tram lining, but not the worst of both worlds suspension. After sway bars and coilovers, the suspension is finally decently sporty and stable with appropriate level of road contact feel for a GT. That's with 18 inch rims.
My quandary is whether 19 inch rims + 40 series tires will still be a good ride. I think we've pretty much answered that 35 series on 19 inch rims is bad idea.
40 will definitely ride better but either way I would seriously consider going with forged rims.
The previous owner of my '06 bent a factory wheel on a pothole. He went to his local Lexus dealer and left with 17 inch IS250 wheels and new tires. The story was not clear but it sounded like his dealer suggested it. He said he was happy he did it. I never had the chance to compare the ride quality with other tire or wheel sizes but from what I've read I'm sticking with the 17's. The ride is smooth and enjoyable which is important to me. I'm not suggesting that anyone follow what I have but I wanted to share my experience with 17's.
I can see how the 17's would be smoother. My 16's definitely are, but look ridiculously small. They do their winter job, though. I have on occasion been tempted to put summer tires on my 16" rims, but then I look at them..... uh no.
02-07-21, 10:12 AM
Request for Ride Quality Experience 19 inch vs 18 inch
