pemarsh

I have noticed that compared to my LX470 that the 570 rides firmer over bumps and irregularities in the road. The dealer said this is to be expected due to the new high profile tires.

Just out of curiosity, can you change these to lower profile tires without messing up the speedometer or ride of the 570???

ggebhardt

Small or lower profile tires will change the speedometer. Anytime you change the diameter of a tire it will spin faster at the same given speed causing the speedometer become inaccurate.

I would also think that higher profile tires would give a softer ride and not a harder one. I think the dealer had it confused.

mikeivan

I agee.

Perry, do you have Michelins or Dunlops? I think my tires (Dunlops) are noisier than the Michelins on my old 470. I was riding yesterday with the windows down to air out the smell (bad BBQ) and every street expansion joint sounded like a pistol shot. However, my 570 rides way smoother than my old 470. I drive "comfort" in town. My tire pressure is a little low (32#), going in for my 5000 next week. Another big road trip next month, with some off roading.

ggebhardt

I went from the Dunlops to the Michilens after about a 1000 miles and they not only were more quiet but gave a better ride. The Dunlops were horrible on the expansion joints on Jacksonville x-pressways! I should have made the dealer change them before delivery, over a $1200 mistake. I am running 34-35psi and the Michelins still look low and I have many tell me I am getting a flat tire.

The dealer told me to run 35 lbs which I would think would make the ride rough but it is good for me.

pemarsh

the dealer was right...i was wrong....just got my terms backwards. The lower profile tires on the 570 give a much more firm and less forgiving ride than the higher profile tires on the 470 (dunlops). I have michellin latitude tires on the 570.

Expansion joints on the expressway are such a pain now, as opposed to my 470 where i seriously never felt anything at all.

When you look at the tires on 570 vs 470, there is a lot of extra rubber on those 470 tires...must offer a smoother ride.

I was just curious what it would take to put a higher profile tire on...i woudd think i would need a smaller rim/wheel--whatever its called.

tigmd99

Wow...this is shocking to hear!! I would imagine that the new LX570 would ride very well esp. with factory tires because i assume that Lexus would optimized the ride. The smart engineers could easily compensate for lower profile tires by adding more compliance in the suspension (or whatever they do).

BTW, what suspension setting are you using?? Comfort or Sport or in between?? Does it matter much??

To tell you the truth, i doubt that switching to a different tire brand (with same size & rim) will make THAT much of a difference in ride quality. Yeah, it may help with handling or it may off-road better, but that is not what you're complaining about. This just sounds weird that Lexus could have messed up the ride quality on the new LX570 simply because they went with bigger rims and lower profile tires...there are ways to compensate for these changes. It is just not like Lexus to do that.

You can change to whatever tire and rim combo you like...as long as the circumference or diameter of tire stays the same, your speedometer will be OK.

My advice:
1. Check tire pressure on all your tires and set it to FACTORY RECOMMENDATIONS (not what your service nor your tire guys says). This also applies to aftermarket tires (on stock rims) of the same size as stock tires.

2. Set your suspension setting to softer setting if possible.

3. Make sure that the Lexus people check all the shocks and electronic gizmos in the suspension to make sure that they are functioning right.

If the above is OK, then i would then consider changing out the rims. But whatever rims you pick, make sure that it will clear your brake calipers and have similar offset as stock rims. (Offset of rim can be found in your owner's manual in the "spec" section.)

Can changing tire (with stock rims) make a HUGE difference?? I doubt it IN MY OPINION because the factory tires are already highway-bias tires. In addition, you may be wasting money for nothing since if you change your rims later on, then you will have to junk your tires anyway.

Going to a smaller rim will give you several benefits:
1. Better ride
2. More tire choices AND cheaper tire price (BIGGEST benefit)
3. Less chance of curb rash (scratch on your rims from hitting curb)
4. Possibly lighter rim/tire (more rubber, less metal) = possibly a nano improvement in fuel economy, easier on your brakes, etc.

Bad of going to a smaller rim:
1. Steering response is more sluggish (more rubber, less metal = less steering response)
2. Less bling-bling

Good luck.

pemarsh

What an awesome reply!! Thanks.
Dont get me wrong...its not a bad ride, but not as compliant and soft and accommodating over bumps as my 470. I have tried all three settings...comfort setting makes a bit of a difference.
One thing that i did a while ago was deflate the tires...someone at the dealer had them so over inflated it was nuts...that made a difference a while ago, but still not up to par as my 470. Just my opinion.

tigmd99

This is a pet peeve of mine. I can barely accept a tire store not knowing your factory tire pressure settings. But, a freaking Lexus "technician" not knowing it??!! I thought that it is common knowledge that the factory tire pressure recommendation is on the DRIVER'S SIDE DOOR JAM. But, for the love of tires, these tire specialist(s) don't seem to know it!! What is so damn hard to look there and follow it??? It seems like there are two extremes that these "tire specialist" or technician follow:

1. Every tire is at 35 psi, or
2. Look on the tire and pump it to "MAX PRESSURE" as per tire inscription

It always amazes me at the ignorance of these technicians!