jjparker

Here's a question for those of you with 2008 and 2009 RX350. Can you maintain say 32psi tire pressure on 4 tires but keep the spare at say higher pressure like 36psi without setting the tire pressure monitoring alarm off? I'm asking because on my old car I always kept the pressure higher than spec on the 4 tires in the winter time due to cold temperature but changed it to just 1 or 2 pounds over when the weather warms up. I always kept my old car's spare tire "higher" than the 4 since it's a pain to check the tire pressure. On the RX350 I just acquired, it is even worse since you have to remove the spare tire cover from the underside before you can lower it to check the pressure. If I keep a higher pressure in the spare as compared to the other 4, will this "uneven" tire pressure cause the tire pressure warning to go off? Does anyone know how sensitve these tire pressure sensors are? Thanks.

hamop

Just a hunch, from what I've read.... only low pressure is detected. My new RX had 37psi on two tires, much over the 32...and no warning.

YWW

On my 2008 RX350, I maintain 31psi on the 4 tires and 36psi on the spare with no problem at all. I believe as long as you maintain above the minimum required pressure, you should be OK. My friend who also has a new RX and the tire pressure on her 4 tires were right around 26 to 27psi when she got it (and she didn't know it until her first 30-day dealer inspection) was way below the 30psi spec. The tire pressure monitoring system never came on even at that low pressure. Not sure what pressure it has to drop down to before it'll trigger the warning light.

catdaddylo

I have a 2008 RX350 and I noticed the air pressure valve covers are metal and fairly large. Are these the sensors ? When you buy new tires do you transfer the sensors to the new tires or do you have to buy new ones from Lexus ? Are they internal ?

The G Man

The medal air pressure valve covers or caps are used to indicate to the service people that you have a tire pressure monitoring system. The sensor itself is inside the tire attached to the air valve stem. They can be transfer if you change tires.

catdaddylo

Got it. Thanks G Man.