Maximum PSI ?

39F/40R

 

38F, 37R

 

Mine came from the factory with the tires over 45 PSI. I can't remember how high, maybe around 50? I would not recommend it. It was like driving on ice. I let a lot of air out as soon as I realized it.

Now I aim for somewhere between 36-40.

 

I have read that Toyota pumps the tires up quite a bit when they prep the car for overseas shipping. It's part of the dealer pre-delivery checklist to set the pressure correctly.

 

Anywhere from 40/38 to 42/40. If they get a little lower, I don't consider it an emergency.

 

40-42 all around.

 

... which is often not done.

 

Common practice in the industry. Read 80psi for BMW or Mercedes.

And I've had dealers 'correct' my tire pressure whenever I brought the car in.

 

36R 38F (slightly over-pressure WAG).

 

Yes, me too, as part of their tire rotation.

Pumping them up to the very-low 40s PSI, I admit that’s a bit on the high side, but I also confess that I don’t check and top off tire pressure as often as I probably should. So on the average, it’s probably a bit lower than that.

 

I ask them not to adjust the pressures, and they have not. I only have the dealer touch the car for warranty or pre-paid maintenance work, so it's not a frequent occurence.

 

I've had both front and rear set at 38 all summer, but now they are showing 34-35 in morning and 37-38 in the afternoon. This is cold pressure, but morning temp have been in 40s, afternoon temp in 70s. Humm, I may have to pump-up a few psi just for morning commute.

 

What device/display do you use to get digital tire pressure values for each tire?

 

External TPMS like this one. Sold at Amazon for anywhere from $20 to $100 a set. I have cheap $30 one. The external sensor replaces the valve cap. It is big and ugly, but does a job. I bought them for my winter snow tires on separate rims without internal TPMS sensors. Works much better than dummy TPMS warning system that came with the car.

If you do put them and if your region experience salt on the road, just make sure to apply some corrosion preventive spray on the valve thread. They tend to seize quickly, and if they do, you will have to destroy the sensor and/or valve stem to remove them from the tires.

 

Ordered this one from Amazon. I guess it's shipping from China since delivery (with free shipping) is estimated to be sometime in the first 3 weeks of October!

Any brand of corrosion preventative spray to recommend? We get lots of road salt applications during the winter in Eastern PA.

 

Yeah, that's why this one is cheaper than other similar models that you can get in a few days. If you picked one that is Amazon PRIME eligible, the price would have been $30-$40.

I used WD-40® Specialist® Long-Term Corrosion Inhibitor 6.5 oz. | WD-40 over the last 10 mo. But it is petroleum base which may not be suitable to use on rubber, and it is expensive. Someone told me this WD-40® Specialist® Water Resistant Silicone Lubricant 11 oz. | WD-40 works better for this application. I have not tried it yet myself, though.

You may also want to have some extra battery handy. 3V CR1632 battery, you can buy them at any hardware store or super market, but cheaper if buy bulk at Amazon. The battery supposed to last over 1 year, but mine lasted only a few months for the first set. Since the sensor has no on-off switch (the receiver on the other hand has on-off switch, and it comes with rechargeable battery not a fixed coin battery), the battery may have been already drained quite bit by the time it was sold. I also have to say that, they are not very high quality products. My first unit quit working within 30 days, and I had to return it. The second unit is working OK for almost 10 months now. Another identical one I bought for my son's car was seized to the valve stem, and had to be destroyed in order to remove them. I figured, if it last 1 winter without issue, still cheaper and more functional than buying internal TPMS sensors and having them re-programed twice a year for my winter tires. I am going for the second winter season with my unit soon.

One more precaution. The unit comes with anti-theft locking nuts. In theory, with the anti-theft locking nut in place, you have to have a special wrench which is included in the kit to remove the sensor off the valve stem, deterring the thieves. But, it just makes installing and removing the sensor onto and from the valve stem more tedious. I don't think any one wants to steal those ugly caps for any reason. You can't use them without matching receiver anyway. I skipped the anti-theft locking nut altogether. It makes much easier to take off and top-up the air as needed.

 

"Any brand of corrosion preventative spray to recommend?"
Very light: Boeshield T-9
Very waxy: LPS #3
Somewhere between: CorrosionX, ACF-50, Corrosion Block

LPS #3 is my favorite if the heavy waxy layer is OK.

 

I don't think you need an aftermarket TPMS. Simply check your tire pressure regularly with a tire-pressure gauge. From my experience they lose (through leaks in the rubber) about 1 psi per month.

However, you also need to compensate for temperature changes -- ideal-gas law. Moreover, they may lose even more pressure if the temperature drops to near freezing or below because of the water vapor in the air in the tire unless you fill with nitrogen -- as the air will deviate from an ideal gas when the water vapor starts condensing and freezing.

 

Fluid Film works great. It's a lanolin based product, non-corrosive, etc.