sderman

A few questions please (couldn't find this in Lexus' literature or in this forum):

1) Do all RX model levels include a spare? (I thought I saw somewhere a UK thread showing it to be an extra charge).
2) Is the spare located in the inside cargo area? (in my 2007 RX it is located outside/underneath and a pain to access)
3) Is is full size?
4) Do you get a matching alloy wheel or just a steel wheel?

I and many other owners found it annoying that the 2014 ES350 came with a spare smaller (thinner) than the one on the 4 wheels - probably just to gain a 1/100 of a MPG. or an extra few cubic inches in the trunk. You can place a full size spare in the wheel well but then the carpeted area bulges up.

RXOwner

Located inside under the floor of the cargo area.
Not full size and only a steel wheel.

Pretty typical these days.

kitlz

UK might be able to order a full spare as an option. At least that's the case with the 3RX. It requires raising the cargo area floor and changing the floor pans underneath. There's some pictures in this thread. Full spare is probably not ideal on the 4RX since the bumper is higher. I only glanced at the spare in the '16 but it probably doesn't have TPMS. That's something you have to appreciate coming from a 2RX with a full spare and TPMS. I never had the warning light come on in the 330 but I dreaded the thought of having to lower it. I'm glad Lexus went with a compact spare instead. I've used it once on the 3RX. It's fine and stores nicely underneath the cargo floor.

sderman

Thanks! I assume then that (like the ES350) a full size spare will be too high (thick) to fit into the wheel well?

sderman

Thanks Anita. Funny about your comment: It is related to what prompted my thread today: Yesterday, the low pressure light on my 2007 RX lit up. Being from NJ you know yesterday was one of the first really cold days of the season. I knew my 4 mounted tires were properly inflated (32psi) but I was not able to successfully reinitialize. I was long expecting the battery on one of my 5 TPMS's to have discharged from age and figured it was time. As an aside, the Parts Manager at Prestige Lexus told me last year when I got a new set of tires not to be concerned because he rarely sells any TPMSs. So...for the first time since the car was new, I lowered the spare tire from beneath the rear end (not too bad a job in the comfort of your garage) and found the pressure to be 25 psi. Brought it back to 32psi and was able to reinitialize successfully.

So this is why I was interested in the spare location of the 2016's since I plan to purchase one in late spring. But I'm surprised that you think the inside mounted spare does not have a TPMS since it is now so much easier to check on the tire pressure from within the cabin.

RXOwner

It is not one of the small donut types and is full size yet not as wide. It is better than I have seen on many other newer vehicles. Can not tell too much except "SPARE" is clearly on the sidewall.

EXP_Cougar

I am guessing the spare does not have TPMS. The TPMS display on the panel doesn't seem to indicate there's a sensor on the spare.

dchar

I bet Lexus decided to not put TPMS on the spare to save money, save weight/space (not putting full-size spare), and prevent people from driving on the spare for extended periods of time.

mcomer

RX has a part time AWD system that relies on wheel speed sensors to trigger power transfer to the rear wheels. If you mounted an undersized temp "donut" spare it would rotate faster than the other three (3) road wheels and the AWD would engage. Lexus supplies the full rolling circumference spare on a steel wheel to accommodate this (even on the FWD versions) It is rated for 3000 miles use (nearly anywhere in America back to your home).

sderman

Agree that the diameter must be the same (for a variety of reasons). I also seem to remember from some past cars that the thinner tires require a higher pressure compared to the other 4, so a TPMS would not make sense in this case.

kitlz

Ha, ha! I checked the tire pressure from inside the comfort of my 450h today and it was down a few from last weekend. But no light. Temps will be going up too. I'm not worried. And you're lucky we've had rain instead of snow around here. Can you imagine the mess lowering the spare?

Lexus removed TPMS and changed over to a compact spare (their words, not mine) beginning with the 3RX. I haven't read through the owners' manual yet to verify for the 4RX. But I can say when I had to use it two years ago, the warning came on. The spare was set to 60 psi per the sidewall. However the display was reading 1. The bad tire was placed in the cargo area with air still in it so I know it wasn't being read. The display didn't go back to 'normal' until the spare was replaced with the tire after being patched. Like dchar said, maybe removing TPMS is a way to remind people they're driving with a spare on. BTW, the size on mine is 165/90, rim 18". Not exactly a donut but it's noticeably smaller than the other tires.