Drtbk4ever

So it doesn't cause any problems to run without TPMS on the winter wheels and snow tires?

I do this on my Acura and live with the light. Wasn't sure if this would cause more issues with the newer technology in the NX.

My0gr81

Why would it? TPMS stands for Tire Pressure Monitoring System. It's a nanny to remind and/or alert people to check the tire pressure because 95% of them don't. The more reliable and resistant to punctures, blow outs, or slow leaks at the beads tires get, the less people bother to check them.

For the NX, I haven't read anything where any of the other safety systems are affected by the absence of TPMS data. Traction, ABS and Stability controls operate independently and without TPMS data. It has to, since TPMS relies on internal sensor with inaccessible batteries and wireless connection. Any one of them can fail at any time.

Drtbk4ever

Thanks MyOgr.

HappyUp

Why does Lexus dealerships over inflate the tires?

legrunt

The panel on the side of my door states 2.7bar if I plan on going more than 160kmh... That converts to 39.1 psi...

Hmmm....

corradoMR2

Interesting. Can you check your max psi/kpa/bar stamped on your tire? In N.America tires are typically stamped " DOT approved" "for USA, Canada, Mexico only" and typically do not exceed 51 psi max.

jimque

I think this makes sense since during high speeds deflection in the tire is increased. This is prevented by increasing the initial pressure of the tire.

The indicated pressure for going below 160ks is about 32psi which is on the door for US cars since we're not legally allowed to go above 160 (at least in WA )

http://www.tirerack.com/tires/tirete....jsp?techid=72

legrunt

Well, the stamp on my tire sidewall reads max pressure 51psi, ... however, according to

http://www.tirerack.com/tires/tirete...jsp?techid=196

the "max pressure" stated on tire sidewalls are maximum cold pressure, not absolute pressure.

Phew!

corradoMR2

Thanks for the find. So international standards seem to be the same on max tire pressures. Then you should be ok for 39 PSI so the sidewall is stiffer for more stable high-speed ride. But if you have a lot of city driving, consider an in between value of 35-36 to enjoy a more comfortable ride.

legrunt

Yeah, I think I'm gonna drop it to about 36. Not sure how that will affect my consumption readings...

Dunhill421

Hey In case anyone was wondering I found out why everyone's tire pressure has been set so high from the dealer.
My friend is a diag tech at my dealership and he told me these cars sit in containers on ships when they are being imported to the USA and to reshape the tire and eliminate flat spots they over inflate the tires for the first 5000 miles.
He told me if I'm not noticing any wheels shakes/vibrations when driving and I have lowered my psi to 32 on a cold start that it's perfectly fine. It's just something that factory has them do for those reasons.
I never even thought about it. I too was like why is my tires set at 36 cold and by the time the heat up they are at 39-40 psi.
Well now I know.
Cheers

optokki

Yup +1 for this. These cars can sit on a boat or on the lot for extended periods on time. You don't want to develop any flat spots on the tires so the natural tendency for manufacturers is to overinflate them. Its still no excuse for dealerships not setting the correct pressure on delivery day though. I keep my tires at 39 cold. I don't mind the slightly bumpier ride, its still super comfortable and I prefer the more balance handling.

Mr645

The pressure in my tires were set at 42 PSI when the car was delivered. Seems to work well, ride well.

Rdcrow

My tires were around 37psi cold when I bought the car. I dropped them to 32 cold and my MPG has stayed the same.

optokki

37 psi cold is probably perfect for mixed city and highway driving.