I second this. Also, H-rated tires will ride smoother than higher ratings (ie. W, V, Z).

Also, the brand and specific model of tire will affect ride smoothness (ie. Michelin Primacy MXV4 and Michelin Energy MXV4 do not ride the same).

Also, tires set at 32psi (or below due to air loss) will have a noticeably softer ride than tires set at 33 or 35psi.

However, you won't notice any of this until you drive the vehicle often, change one variable, then note the difference in road feel.

For the theoretically softest ride, get a UL with air suspension (check that all 4 corners are levelled to spec), then use Tirerack and other online reviews to find tires that are reported to have the best ride comfort, get 4 of them in H-rating, and set them all to 32.0 psi.

 

I agree with you observations above.

I set the 18" H Rated Dunlops at 32 before leaving for the ride home. They aren't reviewed very highly on tirerack but have only 7000 miles on them - I would have preferred the Michelin's that I have on the 400 but you don't get to choose on a used car. I probably would also have preferred the 225x55x17's to the 245x45x18's but those beautiful 18" wheels look so much nicer than the dull,ordinary 17" ones.

Of course the 225x60x16" on the 400 are going to give the best ride but sure look like truck tires compared to the lower profile ones.

Based only on the first 180 mile trip, I'll probably move to some different tire/wheel combination. The supremely smooth highway ride of my 400 is absent from the 430 on 18's and I don't like it very much.

 

Nice !

 

I was also tempted by the dealer's offer to certify the 430 for an additonal $1400 - which he said was his cost. Ultimately I chose to forgo it as I'll only drive the car about 5K per year. My 400 has needed next to nothing but regular maintenance for the 7 years I've owned it and I'm hoping the 430 will be as good.

 

Will your LS400 wheels fit on the 430? They might just barely clear the calipers. If so you can test them out and observe the ride difference first-hand.

18" DEFINITELY ride harder than 17", which ride harder than 16".... you just need to find the balance you like best.

 

congrats on the new car. I love my 05. you know what, what you are saying about the 400 vs. the 430 compounds again when you go to the 460. last week I said the same things you are saying when comparing my 430 to a 460. so i guess the next generation ls will ride even firmer. its like each generation rides a little harder and handles a little better

 

I spent a little more time with my "new" 06 430 today and it's pretty evident that it's just "more car" than my 400. My 400 on the 16's rides smoother and has better visibility with the lower belt and cowl lines and much thinner pillars.

But in most other respects the 430 is superior. I still love my 400 and will not give it up (yet) but I'm very pleased with the new car.

Thinkin: Funny, I was already considering the wheel/tire swap that you suggested. It wouldn't take very long and would be very revealing of wheel/tire differences. It looks like the 16's might clear the calipers. Maybe I'll try it soon.

No one has been able to tell me what the raised "hump" in the forward center of the trunk floor is for. One of several 430 mysteries that I'd like solved.

 

No one can answer the trunk hump question? What about the spring loaded clip in the left compartment of the glove box - what's it for?

 

Are you talking about the back of the glove box? That may be the left latch for an access door to reach something behind it. Maybe AC air filter?

Did the clips on the glove box door originally have a pen in them? Is there supposed to be a light in the glove box?

 

16s were standard on 01-03 430s. You could probably pick up an OEM set here for cheap. They definitely aren't lookers, but they should dramatically improve the ride. Also, if you want to move to 17s....I'm still interested in OEM 18s

 

I''m going to live with the 18s a little longer but may well be interested in moving to 17s. 16s are pretty much out of consideration because of their looks. They look more "correct" on my 400 because that's what they all came with.

My glove box has a light, but like the 400, only comes on when the parking/headlights are on. It's very dim and not as useful as it could be. I noticed that the 430 has two trunk lights, and improvement on the 400's one light. But the 400 has 2 reading lamps per side in the back seat which work better than the single light in the 430.

I've now checked out everything on the new 430 and the only minor issue is that the power mirror's are a little balky. Seems like the switch is making intermittent contact as it sometimes requires several pushes to get the mirrors to move. Anyone else seen this?

Except for that, everything works properly and the car is just as spectacularly nice as I originally though. With only 27k miles and the "mature" previous owner taking meticulous care of it, the car is as near to showroom new as can be for a 5 year old vehicle.

 

Mirror controls are one of a very few known weak spots, as are the power steering wheel and folding mirrors. Since you opted out of CPO, if you're having any issues with those AT ALL I would pursue it with the dealer if you have any kind of short-term warranty.

 

I agreed to "as is" purchase so any repairs are on me. The mirror issue is intermittent and could be easily left alone. Is the culprit the 4-way switch, or is it more involved than that?

I realized that I was taking a chance by declining CPO. I'll probably only put 5K or so miles a year on the car and I felt that with only about 15k miles of coverage for $1400, that it was a reasonable chance to take. Time will tell if I was a good gambler!

 

Do a search on the mirror issue, it'll help you out more than I can. If I recall, some had luck just taking the switch apart and cleaning it and the switch is often the source of the trouble, but sometimes the motor is the culprit.

 

It may be that the switch just needs cleaning but if its the motor a new mirror is approx $700 - its the only thing that has needed repair so far on my 06 LS.