4TehNguyen

iTrader: (1)

thicker tires makes the car bouncier than thinner tires

tqlla3k

iTrader: (1)

why give him a him a hard time, when you know what he means.

By Bouncy he means that the suspension does not absorb the impact, jossling the driver around.

Thicker tires will not make the car bounce more. In general, Thicker tires will absorb the impact better.

ff_

We took delivery of our ES330 2 months ago, and the tires were set at over 40 PSI from the dealership. That's 10 PSI + over the recommended. In other words, get yerself a tire pressure gauge, and monitor them frequently.

On a side note, I test drove an IS 250 yesterday (without the sport package or larger wheels), and found the ride to be too soft. Which, incidently, is exactly what I'd expected a luxury maker's sporty sedan to be like.

Lets Drive

iTrader: (3)

Interesting thread here. I personally felt the IS250/350 had very soft suspension, and thats compared to the Acura RSX, TSX, 3 series, and even TL. To be honest, I wouldn't say much about the IS reminds me of a real sports cars when it comes to suspension, as the car is obviously a bit heavy and has its share of body roll through corners. I'm currently running stiffer shocks and springs on a lowered car, with 225/45 tires on 16s, and the difference is rather dramatic. Its all a matter of perception, but I can honesly say I digested a host of bumps without disturbance in the IS, unlike the previous cars I had listed. As it may not be solely do to the suspension, you can also help in absorbing bumps, by fitting smaller wheels to a tire with softer sidewalls and greater aspect ratio.

igotanewis

ff, how soft is it incomparison to your ES330? Say over a bumpy freeway?

tqlla3k

iTrader: (1)

You know, I have an RX330 loaner with 18s and 35PSI. It feels stiffer than the IS. I lowered the PSI to the recommendend range of 30. Hopefully it helps.

My last loaner was the ES and it was a lot softer than the IS.

ff_

It's more firm than the ES, for sure. The ES will gobble up most bumps with very little intrusion into the cabin, but at the cost of handling. Still, I'm surprised at how well composed/controlled the ES is, considering its weight and softer suspension. It's not "soft" the way you'd expect from a Camry or Town Car, etc.

Rockville

that is causing the bouncing action but the road itself. There will be some amount of sag in the the suspension with three or more in the car which will preload the springs and leave less room to absorb up and down motion in the springs. It is the damper's job (shocks) job to arrest the "pogoing" of the springs. Even though the road was described as new the underlying concrete sections will have a bowing effect and undulations which load and unload the suspension at speed. This can create quite an unpleasant ride especially for those in the backseat who will feel the trailing suspension directly underneath them. First try another road new or old that is flat. If it is flat there won't be any suspension bouncing unless you are carving turns left and right which is normal body roll. Tighter springs, larger sways and more damping will produce a flatter feel under cornering but will give more feedback from the road surface. A personal taste of balance will apply....More damping less bounce. More weight in the car more intertia to lift and more rebound forces.. Try a variety of roads and make note of your perceptions...This can lead to mods of all types

Rock

Scotty99

After I got a few thousand miles on the car and the suspension settled in, mine softened up a bit and became less jittery. Now it feels perfect.

Frisco

Mine did the same thing. When we first got it pitched and followed every bump in the road. Now after a few thousand miles it is much better. Mine also had 40 psi in all the tires. Setting them to proper pressure also helped alot.

igotanewis

OK, I've got the stock Sport Maxx Dunlop 18" summer tires,

225/40R18 88Y in front
255/40R18 95Y in back

they all measure 35 psi. Where's the recommended range posted? I've looked at dunloptires.com, lexus.com, tirerack... can't find the numbers.

I'd like to try lowering the psi a little bit to 30 to see if the ride gets softer, but I'd like to see some documentation that this is OK to do.

igotanewis

My 4 yr. old daughter had a good time in the back seat saying: "dadadadydydy, momomomymymy". Interpretation: "daddy, mommy" as said from a helicopter or from the back seat of my IS250.

My wife put a barf bag in the back seat holder. Looks good with the black leather interior.

And just to prove misery loves company... as I was jittering down the 101 I happened to look over at an M3 in the next lane... I was happy to see the driver had his head craned forward, away from the head rest, just like I drive... while his wife was actually OK leaning back in the seat, with the headrest slap slap slapping her head like a paddle ball.

rys

Without going out to my car, the PSI is usually posted on the inside of one of the door jambs. (Usually on the latch side on a sticker).

-Brian

tqlla3k

iTrader: (1)

How messed up is the road that you drive on? Unless you are driving over bumps or pot holes, the car doesnt bounce at all

rys

I see you've never been on the 101 in California.

Now that you guys have mentioned it I can see why people would complain, but the ride doesn't really bother me. It feels exactly how I would expect for a Lexus with the Sport Suspension Package (my car).

-Brian