kreativ

What kind of TPMS system is in the '07 ES350? Is it the kind that detects differences in rotational speed between wheels, or the kind that directly reads the air pressure of each tire?

If it's the latter, how much of a drop in air pressure does there have to be for the warning light on the dash to appear in the '07 ES350?

I would like the warning light to come on if the air pressure drops below Lexus' recommended spec of 30psi. So to make this happen, I assume I have to set the cold tire pressure to a certain amount above 30psi, and then reset the TPMS?

Dave Mac

The ES350 has sensor/transmitters is each wheel including the spare that send a signal to a reciever in the car. I believe that 6 psi is the trigger point for the warning so you are correct you would have to set them at 6 psi over the recommended pressure to get the warning you want. I set mine at 3 psi over the recommended level.

Also note that on the only flat tire I have had with this car the tire went completely flat in a short time while sitting in my garage and I noticed it because of a life long obsession with looking at tires on cars. The warning did not come on with pressure down below 10 psi but when I increased it to something like 20 psi the warning did work. I repeated this test later with the same result - why I don't know.

Also as I mentioned the spare is included so you also have to set that where you want it before setting the system. And if the warnng comes on and all your tires look good it is probably the spare.

Dave Mac

kreativ

Do you run yours at 33psi all the time, or did you set it to 33psi just for TMPS initialization? When the Lexus recommended is 30psi, I'm not sure what the safe range to avoid under/over-inflation actually is (i.e. should 30psi be treated as minimum or is 30psi somewhere in the middle of the safe range?). I've been running mine at 31psi.

That's a good point. I wouldn't have thought to check the spare.

Since the ES350 comes with a full-size spare, what's your opinion on doing a 5-tire rotation? TireRack has a 5-tire rotation pattern for front-wheel drive cars on their website, and it seems to make sense to do it (especially if you don't plan on buying the same OEM tires for your next set).

Dave Mac

I set mine at 36 psi and run them at 33 psi. My understanding is that overinflation is better - less dangerous - than underinflation. I set my spare at 36 psi which just gives me a little more time if I get lazy and forget to check it for a while. At 20,000 miles - rotating every 5,000 - my tires are wearing even but I will be lucky to get 25,000 miles while still keeping the 4/32 that I will need for the lease return.

My ES350 is a lease with 4 chrome wheels so I didn't consider a 5-tire rotation. I'm hoping to be able to get through my lease with eventually putting my spare in service and only having to purchase 3 tires.

Dave Mac