Ultra Soft Ride Tire For 2002 Ls430

[akme]

Hello, I am new in this forum and I need some help. I have a 2002 LS430 with about 80k miles on it. I commute to work around Los Angeles.

I just changed all 4 tires this Monday. My previous tires were Invader Sports (made in China). They had about 50k miles on them. I have a medical condition, a herniated disc in my neck which is very sensitive to road vibration. Just to give an example, LS430 or similar luxury sedans don't hurt my neck (with an appropriate tire), but if I ride a camry or even an avalon or lexus GS or ES300, it hurts my neck, regardless of the tire.

My previous tires gave me no problems, but when I changed the tires and put Michelin Primacy MXV H-speed rated (225/60/R16) it started hurting my neck:

http://www.tirerack.com/tires/tires.jsp?tireMake=Michelin&tireModel=Primacy+MXV4&partnum=26HR6MXV4P

I did some web search and found that soft sidewalls for a tire are important to absorb the road bumps. I have several questions:

1. Does the weight of the tire make a difference?

2. Or is it just the side wall softness?

3. Which tire can I choose that has one of the softest sidewalls?

I am guessing looking at tire weights in tire rack that lighter tires will have softer side walls. General Altimax HP is one the lightest at 22 lbs and it comes in H and V speed rating:

http://www.tirerack.com/tires/tires.jsp?tireMake=General&tireModel=Altimax+HP&partnum=26HR6AMAXHP

Also I notice that some tires in this size has a max pressure at 51 psi and others at 44 psi. I saw somewhere on the web that higher max pressure means the sidewalls are softer and lower max pressure means stiffer side walls that don't need as much pressure. The MXV4's are 44 psi, it looks like they have very strong and beefy sidewalls, good for road handling and comfortable ride, but probably not good for ultra soft ride that I need.

If I do replace the tires and it solves my neck problem, I may have 4 of these tires (just used for about 300 miles) for sale later, which I will post at the for sale section of this forum.

The other thing I thought was to reduce unsprung weight and put in a lighter wheel like:

http://www.evasivemotorsports.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=SSR-TYPEC-1670-42-5114&Category_Code=SSR-TYPE-C&Store_Code=EM

This racing wheel is only 11 lbs, a full 10 lbs less than my oem 16" rim. But both the rim shop and tire shop guys told me that it will make little difference in ride quality and they will easily get bent in pot holes for LA area driving.

[SRK]

The tire pressure is determined by the vehicle, which for your car is more than likely around 30-32 psi, not by the max pressure listed on the sidewall. Hopefully you have been running the tires in the 30 psi range. If not, adjust them to that. Any tire at 44psi will ride hard. I can't imagine a tire at over 50 on a passenger car...

The MXV4 would be my choice for a smooth riding tire - I know of no tire that is better in that regard.

[pj8708]

I have run the Michelin MXV4's for three years now and I agree that they have been the smoothest and quietest tire I've used by far. Maximum pressure is a rating of the most inflation the tire can safely handle without breaking the bead. As said, it would also ride like a lumber wagon at 40psi, not to mention the extreme tire wear. Just use proper recommended inflation, the right tire and you should be set.

[akme]

Thanks for your response SRK and Paul. I run the tires at slightly below 30 psi and pressure makes a big difference in ride softness, I noticed, so I try to keep it as low as possible within safety limits. I mentioned the max pressure because it is related to sidewall stiffness/softness. Anything above 40 psi will probably destroy the delicate disc in my neck :).

Another relevant question, do tires have a break in period, lets say for the first 500-1000 miles, before they become softer?

[26Gator]

Another tire option for your LS430 is Hankook. Your model series and mine (LS430 2006) should ride similarly with good tires. I had Michelin MX4's on my LS400, another of the same model series and they rode softly and quietly as well. (You wouldn't be as happy in a 2007 or newer LS simply because they radically changed the series going forward trying to compete with BMW, Mercedes, etc with the sportier/stiffer suspension. We did not like the ride in the 2007 even tho it was also close to our price point for the auto upgrade). These Hankooks were on the LS430 when I recently purchased it. They are EVO V12 Y rated (189mph) and Lexus rec's 33 psi. I tend to add 1 lb to allow for inevitable leakage throughout the month. My Michelin's on the LS400 were purchased at Costco and they use N2 in their tires. The N2 tends to keep the pressures more stable. Some claim that N2 makes the ride smoother but I seriously doubt that claim. Hopefully, the wear factor on these Hankook's will be decent but even brand new they do NOT have a tread wear warranty only a failure warranty. Although you shouldn't precisely compare Tread Wear ratings between different brands of tires, the Michelin's were rated at 400 while these Hankook's are 280. TW is a measure of durability and somewhat related to ride comfort. I really doubt I'll get 60k miles with the Hankooks. More like 30k+. The Hankooks are 245/45/17 and have a very unusual diagonal/arrow groove pattern with a central ridge. The diagonal tread pattern is supposed to get water off the tread better and markedly reduce hydroplaning - a must for cars in Florida where I found the vehicle. They are definitely a summer/rain tire and not a snow/ice tire. Bet I'll be looking at those Michelin's again when the time comes. Can't beat the prices on the Costco tires though. Biggest difference this year with the "discount" at Costco is the fact that you don't get the tires discounted, you get a $70 Visa debit card to spend elsewhere. Pricing is not cheap and the real discount would be a lot better for the consumer IMHO. Michelin is counting on those folks who toss the card in the drawer and forget about spending the cash! Coupons and cards are a pain!

[SRK]

Another relevant question, do tires have a break in period, lets say for the first 500-1000 miles, before they become softer?

Not a sidewall break-in as such. Some claim that the tires need a few miles to wear off the mold release chemical which can make them a bit slippery at first. I don't know if it's true, but it makes some sense.

Michelins have about the flimsiest feeling sidewalls of any tire, but I don't know if that's related to ride quality. I do know that BF Goodrich Euro TA's have very stiff sidewalls, and they ride horribly.

[1990LS400]

akme, I've used Michelin H-rated Primacy MXV4 225/60-16 tires on my 2000 LS400 since Spring 2010 - except during winter - and I have found them to provide an exceptionally soft and comfortable ride - the softest riding tire I've used on LS cars during the 22 years I've owned them. Your perception of the ride quality provided by these tires is very unusual and I have to wonder if something else is going on. Does your LS430 have air suspension? If it does, is the damping switch set to "Normal" and not to "Sport"?

[pj8708]

Another tire option for your LS430 is Hankook. Your model series and mine (LS430 2006) should ride similarly with good tires. I had Michelin MX4's on my LS400, another of the same model series and they rode softly and quietly as well. (You wouldn't be as happy in a 2007 or newer LS simply because they radically changed the series going forward trying to compete with BMW, Mercedes, etc with the sportier/stiffer suspension. We did not like the ride in the 2007 even tho it was also close to our price point for the auto upgrade). These Hankooks were on the LS430 when I recently purchased it. They are EVO V12 Y rated (189mph) and Lexus rec's 33 psi. I tend to add 1 lb to allow for inevitable leakage throughout the month. My Michelin's on the LS400 were purchased at Costco and they use N2 in their tires. The N2 tends to keep the pressures more stable. Some claim that N2 makes the ride smoother but I seriously doubt that claim. Hopefully, the wear factor on these Hankook's will be decent but even brand new they do NOT have a tread wear warranty only a failure warranty. Although you shouldn't precisely compare Tread Wear ratings between different brands of tires, the Michelin's were rated at 400 while these Hankook's are 280. TW is a measure of durability and somewhat related to ride comfort. I really doubt I'll get 60k miles with the Hankooks. More like 30k+. The Hankooks are 245/45/17 and have a very unusual diagonal/arrow groove pattern with a central ridge. The diagonal tread pattern is supposed to get water off the tread better and markedly reduce hydroplaning - a must for cars in Florida where I found the vehicle. They are definitely a summer/rain tire and not a snow/ice tire. Bet I'll be looking at those Michelin's again when the time comes. Can't beat the prices on the Costco tires though. Biggest difference this year with the "discount" at Costco is the fact that you don't get the tires discounted, you get a $70 Visa debit card to spend elsewhere. Pricing is not cheap and the real discount would be a lot better for the consumer IMHO. Michelin is counting on those folks who toss the card in the drawer and forget about spending the cash! Coupons and cards are a pain!

Welcome to the LOC Raymond. Thank you for the excellent information and keep on posting in the future.

One other thing about finding good pricing on tires. My Lexus dealer offers a price match guarantee for any advertised tire price whether local or online from say "Tire Rack" or out of town vendor. I have bought all my tires this way for all my Lexus and Volvo and never spent a nickel more than Costco or anyone else and it is a lot more convenient to have it done while I wait in the "comfy" lounge.

Check with your dealer.

Paul

[26Gator]

Another tire option for your LS430 is Hankook. Your model series and mine (LS430 2006) should ride similarly with good tires. I had Michelin MX4's on my LS400, another of the same model series and they rode softly and quietly as well. (You wouldn't be as happy in a 2007 or newer LS simply because they radically changed the series going forward trying to compete with BMW, Mercedes, etc with the sportier/stiffer suspension. We did not like the ride in the 2007 even tho it was also close to our price point for the auto upgrade). These Hankooks were on the LS430 when I recently purchased it. They are EVO V12 Y rated (189mph) and Lexus rec's 33 psi. I tend to add 1 lb to allow for inevitable leakage throughout the month. My Michelin's on the LS400 were purchased at Costco and they use N2 in their tires. The N2 tends to keep the pressures more stable. Some claim that N2 makes the ride smoother but I seriously doubt that claim. Hopefully, the wear factor on these Hankook's will be decent but even brand new they do NOT have a tread wear warranty only a failure warranty. Although you shouldn't precisely compare Tread Wear ratings between different brands of tires, the Michelin's were rated at 400 while these Hankook's are 280. TW is a measure of durability and somewhat related to ride comfort. I really doubt I'll get 60k miles with the Hankooks. More like 30k+. The Hankooks are 245/45/17 and have a very unusual diagonal/arrow groove pattern with a central ridge. The diagonal tread pattern is supposed to get water off the tread better and markedly reduce hydroplaning - a must for cars in Florida where I found the vehicle. They are definitely a summer/rain tire and not a snow/ice tire. Bet I'll be looking at those Michelin's again when the time comes. Can't beat the prices on the Costco tires though. Biggest difference this year with the "discount" at Costco is the fact that you don't get the tires discounted, you get a $70 Visa debit card to spend elsewhere. Pricing is not cheap and the real discount would be a lot better for the consumer IMHO. Michelin is counting on those folks who toss the card in the drawer and forget about spending the cash! Coupons and cards are a pain!

Welcome to the LOC Raymond. Thank you for the excellent information and keep on posting in the future.

One other thing about finding good pricing on tires. My Lexus dealer offers a price match guarantee for any advertised tire price whether local or online from say "Tire Rack" or out of town vendor. I have bought all my tires this way for all my Lexus and Volvo and never spent a nickel more than Costco or anyone else and it is a lot more convenient to have it done while I wait in the "comfy" lounge.

Check with your dealer.

Paul

[26Gator]

Thanks for that info Paul as regards to the tire matching prices. I'll certainly make those inquiries when tire buying time arrives.

[akme]

26Gator, the only good Hankook I found in my size was a T-speed rated optimo h727 which is 26 lbs, with max 44 psi, so it is as heavy as my MXV4's. About the 2007 and newer LS, that is valuable info, thanks. So I think 2000-2002 LS is the best for people like me as they have 16" wheel option. I have a 1992 LS400 with 15" wheels and it has MXV4 on that as well, but it's not as soft as the LS430.

SRK, yes I have seen on the web about the slippery chemical wearing off. But apparently there is some breaking in for tires:

http://blog.tirerack.com/blog/selecting-the-correct-tire-for-your-needs/breaking-in-your-new-tires

During the week, I can feel the tire softening the ride just slightly, but may be I am just getting used to them.

1990LS400, please note that I am not questioning the fact that MXV4 is a smooth riding tire, tirerack.com reviews give them a 9.0 for ride comfort, reviews from so many people cannot be wrong. But my situation is a little different due to my medical condition, so I guess I need more precise combination of unsprung weight (the weight on suspension assembly including wheel-rim+tire+brake+suspension) that matches with the current strength of my suspension system (coil spring+shocks) that degrades over time (shocks are supposed to be replaced every 100k miles). My LS430 does not have an air suspension. But I used to own a 1995 LS400 some years back, that had an air suspension. Even that one did not have as soft a ride as the current LS430 2002, well at least before I changed the tires.

I am still debating if I should change the tires to General Altimax HP as they are 4 lbs lighter and supposedly have softer side walls. Also I am looking at cheaper racing wheels (less than $150) that may not be as light as 11 lbs., but may be in the 15-16 lb range. I am wondering if anyone has experience with lighter wheel rims.

I will take my time with this project. But I appreciate the input.

From my little web research, I found the following about ride quality:

- it depends on tire how well it flexes against bumps/dips (a heavier wheel can help with this)

- it depends on suspension responsiveness, how quickly and correctly the suspension can negotiate a bump or a dip (unsprung weight must be accurately matched with suspension strength)

The combination of the two movements make it quite a complex phenomenon. But I think adding the new tires with more weight than my previous ones may have put my suspension slightly out of balance, compared to what I had before.

One interesting thing I found from this little research is that the current craze about plus size wheels and thin (low aspect ratio) tires is more a matter of style and personal preference, it actually decreases vehicle performance in almost all respects.

[akme]

Latest thinking:

- use Motegi Tracklite wheel, slightly heavier than SSR Type C (11 lbs), but still quite light at around 12.5 lbs, but less expensive

- use General Altimax HP, the lightest tire at 22 lbs

[pj8708]

"akme",

I was wondering if a c-spine collar has helped in the past to absorb some of the road vibrations.

It's obvious from the avalanche of information to your posting, that there is no shortage of contradicting opinions on what tire/wheel configuration will work best. I agree with you that taking your time and carefully sorting through your options will save you disappointment and money. Lexus is well known in the industry for having the smoothest and quietest ride. Hopefully, your search will complete the package.

Happy New Year to everybody!

[akme]

Paul, is it possible to change my display name by myself, if not please let me know who I should make a request to. I want to change it to just AK which are my initials. My first name is Abul, so I would like to be addressed as either Abul or AK. Also I have not introduced myself at the intro section of the forum, is it too late to do that?

I have been using a foam collar around my neck for some years and a wide rear view mirror to cover blind spots so I don't have to move my neck or head much before changing lanes. The foam collar helps a lot, but it could not prevent the problem I am having now.

Happy New Year and Happy Holidays to everyone in the forum.

[pj8708]

Paul, is it possible to change my display name by myself, if not please let me know who I should make a request to. I want to change it to just AK which are my initials. My first name is Abul, so I would like to be addressed as either Abul or AK. Also I have not introduced myself at the intro section of the forum, is it too late to do that?

I have been using a foam collar around my neck for some years and a wide rear view mirror to cover blind spots so I don't have to move my neck or head much before changing lanes. The foam collar helps a lot, but it could not prevent the problem I am having now.

Happy New Year and Happy Holidays to everyone in the forum.

Hi Abul,

I'll look into your profile as soon as I can, probably Monday, and get back to you.

Paul

[akme]

I have replaced the Primacy MXV4's with Altimax HP. The lighter Altimax are definitely better for my neck.

How many posts or how long will it take for me to become a regular member, so I can post these tires in the for sale thread?

[akme]

I am bumping an old thread to provide some update about my experiences with different sets of tires.

First I tried a set of Michelin Primacy MXV4's, it was a harsh ride, specially for my neck with medical condition. Then I tried a set of General Altimax HP, but these did not solve the problem either, I still had neck issues. Then I tried two different T speed rated tires on my front driver side as a test:

1. Hankook Optimo H727

2. Goodyear Assurance Comfortred (not the more recent touring version)

Hankook seems to have the softest ride. So now I have a full set of Hankooks, which I will take on the freeway tomorrow. I will update the results in a few days.

Incidentally I have already sold the Michelins at about half the price on craigslist. I am ready to do the same with the General set and one piece Goodyear.

My earlier guess that tire weight is a big factor about softer ride, turned out to be mostly or totally false. It turns out the soft ride has nothing to do with tire or unsprung weight, but everything to do with sidewall construction and to some extent the rubber compound and overall reinforcement design (internal steel belt), again, these are my guesses of course. Hankooks have the softest side wall and the softest rubber compound. The trade offs are handling and fuel consumption, which are not important for me.

For most people who do not have a medical condition like me, handling and fuel consumption are important factors. But if someone is looking for the ultimate soft ride, from my experience there is nothing quite like the Hankook Optimo H727. I will find out in a few days if it finally becomes a worthy replacement for the Republic Invader sport, which took good care of my neck.

As for the General tires, they are lightweight (4 lb less than Michelin and Hankook) and relatively soft, they made the LS430 feel more nimble and sporty, accelerating and braking was easier and mpg went up by at least by 1-2. But unfortunately they are not for me.

[pj8708]

I have replaced the Primacy MXV4's with Altimax HP. The lighter Altimax are definitely better for my neck.

How many posts or how long will it take for me to become a regular member, so I can post these tires in the for sale thread?

I believe the magic number is 10.

[akme]

I have replaced the Primacy MXV4's with Altimax HP. The lighter Altimax are definitely better for my neck.

How many posts or how long will it take for me to become a regular member, so I can post these tires in the for sale thread?

I believe the magic number is 10.

Thanks Paul. I guess I will need just one more post. The latest update is that the Hankook Optimo h727 are definitely softer than generals or michelins, but they still hurt my neck. Hopefully my neck will get used to it with time.

The other option I am thinking of is putting a floating air suspension seat in my 1992 ls400, which I bought several years ago, but I am not sure what kind of modifications it will need or if it will fit into that car at all. My friend Fred at Tom's Tire is going to put 2 seats like that in his jeep. I guess it will be much easier to fit them into jeep, suv, van or pickup-trucks as they have higher and taller seats. This is the seat I have:

http://www.bostromse...oducts/t905.htm

Manual:

http://www.bostromseating.com/products/905L905910.pdf

But I worry about legal issues from DMV.

[pj8708]

It certainly looks comfortable. How sensitive is the air suspension and how quickly does it react to the road vibrations? Also what DMV leagal concerns do you think there would be.

It's certainly a source of frustration for you I'm sure.

Paul

[akme]

The reaction time should be quick enough, these are standard equipment for truck and bus drivers and they reduce operator fatigue. Essentially its a degree of isolation from the cab/body of the vehicle, so the seat remains floating in air spring, with a damper to damp oscillation, just like any standard suspension system. My seat has a travel of only 1.2", which is appropriate for the small room inside cars.

I am worried that this could be an unauthorized modification and there might be laws against it for safe operation of vehicle, I did not look into vehicle code in detail yet, of course if they can figure it out that it is a modification just from the looks of it.

It would have been so much better if the car companies could include these kind of seats as a luxury option. Imagine using these seats that isolates the drivers and possibly passengers from the cars body, while the car itself could have the sportiest of suspension and wheels for handling and then we could have best of worlds, luxury and sporty handling. This kind of pneumatic suspension isolation is already done for truck cabs and seats, wonder why it did not trickle down to smaller vehicles, it definitely does not cost so much and it is quite a simple technology.

[akme]

To admin/staff, thanks for changing my membership status from New to Regular.

[oldskewel]

Hi Abul, good luck solving this problem. Sorry to hear about your condition - hope it improves. It sounds like you're really intent on getting a soft ride, so here are just a couple of extra thoughts that might help:

Speed rating - it will be hard, for liability reasons, to get a straight answer on this from any professional. But (flame retardant suit on, now), as a non-professional, I'll say that it seems like you'll need to stiffen the sidewall a lot to make the tire hold together for an hour at 130+ mph (or whatever). If you don't plan on doing much of that, you might consider a lower speed rating, which should have a softer sidewall. It is true that it will affect handling, but again, you have other concerns. Most reputable professionals will not install a lower-rated tire, so that's another obstacle.

Is 16" the smallest wheel that will fit? My '91 has 205/65R15. Smaller wheel ==> higher aspect ratio ==> potentially softer ride.

Now for something completely out of the box ... have you considered a different / modified seat? E.g., adding a suspension base to it.

Edit - now I see you have thought of it. I'd expect that to help.

[akme]

Hi oldskewel, yes the speed rating does make a difference. I am using Hankook optimo h727 97T and it is softer than other H rated tires like Michelin Primacy MXV4 and General Altimax HP. But the speed rating is not everything. The T rated Goodyear Assurance Comfortred sidewall was not as soft. The H rated Republic Invader sport I had before, the whole tire as well as the sidewall was softer than the Hankook, so it all depends.

As for seats, I just found out that Bostrom shipped me the wrong model, which will never fit into ls430, the right model they were supposed to ship was t905L which may fit. But I bought it in 2008, so I am talking with Bostrom now to find out what they can do about it.

In the meantime, I found some really low profile seats that will fit into all LS models and most any other cars for sure:

http://www.kabseatin...oupid=7&appid=9

CVG which owns kab seating also bought Bostrom.

http://www.knoedler....-low-rider.html

So I am confident that either the Bostrom or the Knoedler above will be the right size, the Kab model I could not find anywhere online. But putting in a seat like that would not be easy. Seats, specially programmable driver seats are tied with the central computer, so I am not sure what kind of effect it will have on the computer, seat-belt sensor etc. I will try to use the same seat-belt, but I am not sure if it is possible.

Once I have the right seat, I will probably try to install it in my 1992 ls400 (which by the way has 15" wheels) and see if it works. And the next step will then be to put it in the ls430.

[akme]

Paul, is it possible to change my display name by myself, if not please let me know who I should make a request to. I want to change it to just AK which are my initials. My first name is Abul, so I would like to be addressed as either Abul or AK. Also I have not introduced myself at the intro section of the forum, is it too late to do that?

I have been using a foam collar around my neck for some years and a wide rear view mirror to cover blind spots so I don't have to move my neck or head much before changing lanes. The foam collar helps a lot, but it could not prevent the problem I am having now.

Happy New Year and Happy Holidays to everyone in the forum.

Hi Abul,

I'll look into your profile as soon as I can, probably Monday, and get back to you.

Paul

Hi Paul A.,

Bumping an old thread with some new update. Also please change my username to AK or akalam.

Here is the latest:

- I have installed the bostrom 905L air cushion seat in the 1992 ls400 and it works great so far. It cannot absorb the higher frequency sharper vibrations, but gives a smoother ride, specially for larger bumps and up and down movement of the car. The result is that my back and neck feels better and I feel less tired after my 30 miles commute each way

- I also put in new Hankook optimo H727 tires 205/65r15 in the ls400. The result is that unlike the Michelin MXV4 where I could keep low pressure, below 30 psi, on these tires, I have to keep the pressures (cold) at around 34 psi front and 33 psi in the back. When they warm up after some driving, the pressure is around 37 psi front and 36 psi in the back. This produces a much rougher ride. But because of the lower unsprung weight of wheel+rim compared to the 2002 ls430, the ride is much smoother overall. You get kind of gliding feeling where the wheels respond to bumps more quickly without moving the car body.

The michelin MXV4 V rated had a more stiff sidewall, so it was possible to ride on lower pressure. Unfortunately I sold those tires on the spur of the moment, so I cannot try them back on to compare them. But I think its ok, because depending on sidewall stiffness would not be a good solution. I would rather find a solution with soft side wall tires and perhaps have some way to put bigger tires.

With bigger tires in mind, I did a little experiment, I put in a couple of Kumho KR21 235/70r15 (2 inch bigger diameter) on the front wheels of ls400 to see if bigger side walls are going to make the ride softer as I could use lower tire pressure with these bigger tires of higher weight capacity. They fit without rubbing on any sides, look a little big for the car, but ran ok even on freeways. But the ride was not as smooth as the smaller lighter tires (205/65/15 hankook). Because of 3 lbs higher unsprung weight, I think they were a mismatch with the suspension and did not feel the smooth glide feel I had before. So I went back to the smaller tires.

I am now thinking to buy these wheels:

http://www.amazon.co...0/dp/B007MEK8O0

They weight about 14.4 lbs.

Does anyone know the weight of stock oem aluminum wheel rims (15x6.5) for 1992 ls400 and (16x7) for 2002 ls430? I may have to weigh the wheel+tire to find this.

I am hoping that the above wheel rim will reduce the unsprung weight by at least 6 lbs and will enable me to use the bigger kumho. If the kumho's do not feel as smooth, I will try the biggest hankook h727, which is 215/70/15.

I am also thinking of moving towards Toyota prius 2006 with hankook h727 tires (205/65/15), motegi traklite 1.0 10lb wheels and if it is as smooth riding as the 1992 ls400, then install the existing bostrom air cushion seat or a knoedler ultra low profile seat in it. Prius will definitely save money for the daily commute and have possibility of plug-in conversion.

Finally the installing the Air Runner airbag spring system for $7000 is the other expensive option. But it is beyond my budget now and it may not be needed after all. But the Air Runner distributor/installer in Anaheim offered to try a test ride. If I can afford it in the future, I should try a test ride to see how it feels.

May be I should also try some inflatable seat cushions like this:

http://www.magellans...e-seat-cushion#