FlexnLexus

I’m curious to know if anyone knows how automakers are able to achieve a smooth vibration free ride with such thin tires?

Such as 18-22” wheels with say 235/45 or even down to a 235/35 series tires? How in the heck can any engineer, engineer out the harshest of vibrations and bumps from the road using tires that barely have any rubber between the wheels without causes a severe increase in NVH? Specifically in luxury vehicles.

The only thing I can think of is using massive body mounts and beefier subframes, and control arm bushings to help absorb the added road shock.

So what gives?

BB9

It was achieved without rubber tires at all. That thing they have in Japan called Shinkansen. Goes really fast, real smooth and has no rubber tires. LOL

Striker223

It's done via advanced suspension, combo of very stiff structure, geometry, stoke length, rebound/compression valve tuning, and ultimately air suspension bag tuning. Modern air setups have multiple bags that can be tuned to absorb the known frequency of the tire/rim package in comfort mode.

Bushings help as well, having a lot of them is better than fewer and a multi-link arm setup allows the wheel to remain in "perfect" alignment with everything to help ensure the system works as intended. A 40 series tire is actually quite easy to make extremely smooth these day.....

FlexnLexus

Yup, makes sense for the higher end stuff, but what about the average FWD vehicle with a regular McPherson strut suspension?

It’s interesting because if you take a look underneath at most FWD cars front end suspension from 20 years ago or even from the 90’s, and take a look at something made recently, they look exactly the same, minus a few differences in tie rod length, sway bar sizes, strut sizes/valve tuning, and small bits here and there, but essentially, they all look very similar as the McPherson design hasn’t really evolved at all.

Now the rear suspension setup is a different story, but again, they are all very similar in design utilizing a multi-link setup like you mentioned but still can ride like crap on rough roads.

But even having more wheel articulation, doesn’t mean a better damped ride. For instance on expansion joints, the impact from driving over those can be very jolting which doesn’t have anything to do with extended wheel movement, but rather, how the car dissipates those energy forces from entering the cabin through different mechanisms. Extremely rigid and dense body structure having very strong metal components to absorb the vibrations is also another obvious one.

In my experience, every car I have ever driven that have low-pros with larger wheels, like 55 series and under, don’t do as good of a job at suppressing harsher road impacts vs a taller tires/smaller rim, it’s simply physics. We all know looks is what sells almost anything, and for years with the Donk movement, sitting on dubs was what sold to younger audiences.

Even when I was in my 20’s, I hated big rims and thin tires, because I always thought to myself “Man, I can’t imagine how many flats that guy goes through in a month”, and how much money he’s throwing away just to look cool in his mind. I guess I had a different thought process lol.

I understand that today, a 60 series tire on a sedan won’t cut it anymore in the styling department for all automakers in this day in age, but they have done a disservice to people that simply want a smooth soft ride without the fear of getting a flat tire and a possible busted rim after hitting a pothole. I do miss the days of the tall sidewall even if they look pretty stodgy and old because that additional rubber between the wheels definitely helps cushion road impacts.

Now if you’re someone that’s into drifting, sporty feel, or that VIP look, then by all means go for it, but I just wish the aftermarket industry or the OEM’s for that matter would offer alternatives to people that just want a smoother ride utilizing a smaller wheel, and a larger tire combo. I can’t stand CUV’s and don’t want to have to buy a truck or an SUV to be able to get a smaller wheel larger tire combo either.

Striker223

Uh why did you ask a question when you already seem to know the answer?

Even basic suspensions benefit from optimizations and improvements btw, that's why a current econobox still rides better than an older one. Tires help sure but higher sidewalls make a car worse to drive, you can absolutely have both sharp to drive and extremely comfortable these days if you have a high end car

FlexnLexus

I like to hear different opinions and perspectives that’s why. True that, my 2017 Chevy Impala I used to own rode really nice, although a bit too stiff to my liking compared to my 460, but that car was pretty well “hushed” with zero wind noise.

My 460 and 430 however are perfect riding cars that give you a sense of control without the complete disconnected feeling like say, driving a Town Car.

Tdes395

All suspensions are inferior to this (see video). A REAL suspension, the BOSE one just laughs at low profile tires while even the best mainstream suspensions shudder at the thought of offsetting the roughness of life profile tires.

sktn77a

iTrader: (2)

Car manufacturers sacrifice ride for...... appearance - the appearance of performance! I've driven cars for almost 50 years - from early 80 series tires, to their performance equivalent +1 (70 series tires)! Then 60 series tires (ugh!) to 50 and 55 series (Ugh, Ugh!!), and now 45 series tires (Ugh, Ugh, Ugh!!!)! Manufacturers modify their suspension to take into account the rough ride of low profile tires, but you never get back what you give away! The ride in my 2014 LS460 (245/45R19) isn't a patch on my 2007 LS460 (235/55R18) and neither are as good as my 2001 BMW535i (225/60R16) or my 1992 BMW525i (205/65R15)!

Striker223

Guess I must be insane then since my 430 has the worst ride of my flagships even though it had the most sidewall.

Gerf

swfla

iTrader: (1)

OMG GERF, I remember this when I was a child!

SW17LS

Funny because my 2017 LS460L with 19s rode better than my 2015 LS460 with 18s.

Tires are a big component but not the be all and end all of the equation. For one in my case my LS460L had 5 inches longer wheelbase and air suspension, which more than made up for any difference in ride quality. I also run lower than factory air pressures which are set for fuel economy.

My 2020 S560 with 45 series tires on 19s rides better than any car I have ever had including LS400 and LS430 on 60 series tires (430 was 55 series)

swfla

iTrader: (1)

I find the cutting edge tech very interesting. This type of tech can work it's way into regular use years down the road. Almost like a window into the future.

Striker223

Not really. Flagships had air in the 90s, and it's still only really found there due to cost. Mainstream cars will continue to have struts

SW17LS

Strut technology is improving too