encore888

Good points all, I concede the convenience of knowing each tire, but myself wouldn't mind checking all four tires anyhow.

It brings me back to the old Discovery Channel program "Beyond 2000" and a segment I remember which said, "cars in the future will be able to warn you if a tire is punctured!" What a concept!

garyr

Personally I agree with most here, if you say your pursuing perfection yet you use antiquated monitoring equipment we should question why, it's insulting to me knowing there are much better systems out there.

I have a $50 tire monitoring system on my motorcycle, not not only does it tell me which tire has what amount of air pressure, it also tells me the temperature of each tire at all times. That to me would be pursuing perfection if my LS has such a inexpensive system.

My wife has a 08 GL 450, about a week ago she got her first flat ever. She drove home from the store hearing a flapping sound. She drove 5 miles home and than when she went back out to use the truck her tire was flat. The sensor on her 75k truck never went off. She drove it on a flat and never knew, the flapping sound was the belts breaking. I had to replace the tire at a tune of $300. I called MB and they could not care less. The truck is going in for it first service next week, I demanded they check the tire sensors for proper operation.

I guess my point is I just hope they work on the LS.

Johnny

Best way to check if it works is take the tire pressure on one tire down to 25psi and watch for the warning to come up on your center display. It will and the display will disable all other info until you put air back in the tires. One of my tires suffered a puncture last year on my 460. The warning was so persistent, it was almost annoying.

jgamze

Again, what a hassle to have to do that in an expensive, luxury vehicle, expecially in view of the fact that you don't have to do that in much luxurious and less expensive cars. Why doesn't Lexus, in their relentless pursuit of perfection, simply change the system to one that is already in existence and that is much more user friendly?

jgamze

I mean in less luxurious cars.

EludiumQ36

Coming late to the party here but have to add an argument I haven't seen here explicitly. The display of five PSI's is only useful if they're specifically ID'ed with a tire, otherwise they're no more useful than a simple "Low Tire Pressure" warning light. Lexus was stupid on this, no doubt, and it's technically shameful however it's not a critical buy-or-not issue. It's just an unnecessary annoyance.

jmcraney

The Lexus TPMS, a direct measurement scheme, provides many advantages over "simple Low Pressure warning light", which is an indirect measurement scheme. The indirect measurement systems can not detect when all four tires are low, when two tires on the same axle are low or when two tires on the same side are low. With an indirect measurement system you must drive several miles before it can tell you a tire is low. If your tire is low when you start you may drive to an unsafe location before you find out. With an indirect system you don't have any indication about the need to add pressure until a tire is seriously low, while with a direct measurement system like Lexus employs you can see the pressures if you choose to look. An advantage of the indirect system is that there is no need to be concerned about about tire positions after rotation. However with the direct measurement systems, you must resynchronize the display after the tires are rotated and if you fail to do that correctly the display indications are ambiguous and there is no way for you to know that.

I remain very happy with my Lexus and the present design of the TPMS. For me it provides a lot of very useful information.

Johnny

Sorry, but I completely disagree with your statement. There are two schools of thought or approaches on TPMS. Both of them have advantages and disadvantages. If the only concern you have is the inconvenience of locating the position of the wheel, then that is a weak judgment. I suggest you do a little research before making such rash conclusions. To say you don't like it is fine, but to tar Lexus with a broad brush is going overboard, methinks.

jmcraney

Some of you folks who prefer the cars with the displays that show tire location versus pressure, here is a question for you: do these cars come with a full size/pressure sensor equipped spare tire? And if they do, are you able to tell the inflation pressure of the spare through some display? And if you have to install your spare tire in place of a flat tire, are you able to see its pressure on the dash display without resynchronizing the display?

jgamze

Again, I am not tar and feathering the car. I just don't understand why Lexus has not employed a clearly more useful and more user friendly system, such as in my wife's Honda Odyssey, whereby if one tire is low, I can see which tire is low and just fill up that tire accordingly. Having driven cars with both systems, I can tell you that the system in the Odyssey is much easier to use, even if it doesn't give you the pressure of the spare tire. I would much rather have the pressure of the tire that is being used than I would of a spare tire which may or may not ever be used and which pressure I will likely check anyways if I have to used that spare tire. An by the way, the pressure in the Odyssey does not have to be that low before the monitor system alerts me.

jmcraney

I understand and respect your position. Maybe next time you can get a car that leaves you with a good feeling.

Helmar

WHATEVER you may think of the Lexus TPMS, my friend wishes he had one.

Last night I was following his recent model Cadillac CTS in my Lexus and noticed that his driver side rear tire was low.

When we reached our destination, I told him and he called On-Star. The technician said that that tire was flat (a nail), one of the front tires had 14 psi, the other front tire was 22 psi, and the other rear tire was normal.

An early warning system is always welcome.

HBH

Johnny

One day On-Star will reach down from its geosynchronous orbit and change that tire...

Helmar

I fear that I was unclear.

My friend used On-Star to send a technician to the car, where he changed the flat and measured the pressure in the other 3 tires.

On-Star was NOT able to check the pressure remotely.

That's why I started my post with the statement that he wishes he had a TPMS.

HBH

jmcraney

There is a lesson here. The permeation loss is 0.5-1 PSI per month and the change for air temperature is 0.5-1 PSI per 10 deg F (up for warmer and down for cooler). If you haven't checked them for several months and the weather suddenly turns cold they can easily be down 6 PSI - enough for the Lexus TPMS to get upset and for tire performance to be compromised. The tires suffer these effects uniformly so if one is down they will all be down. If one is significantly different then there is some other problem like a puncture or a leaking valve.