Tire Pressure on 19" Wheels

[jerry33]

My point was that if the Tesla service techs don't know what Tesla is saying the starting point should be, how are we supposed to?

I realize there isn't a heck of a lot of difference between 45, 47.5, and 50. The problem is that Tesla can't get their ducks in a row on something this basic. To me that's indicative of a much bigger problem.

I can assure you that it's a problem every place that services tires has. There is an unfortunate lack of training when it comes to tires. It doesn't help that there is a lot of cruft left over from the 1950s and 1960s. This lack of training is one reason why sidewalls are no longer patched, even though with proper patches and methods some injuries could be safely patched. In general tire service is given to the most junior person. Unfortunate, but that's how it is.

 

[WillAustin]

S85D March 2015 Build/delivery. My door jam sticker shows 50psi. Also my tires were delivered inflated to 50psi.

My 19" April 2015 S85D shows 45 psi, and were delivered at 45.

 

[wart]

Just another data point. My 85D was built at the end of May, 2015. 19" base wheels with Primacy tires. Coil springs. The sticker shows 45 PSI. I checked at delivery and they were at 42; I asked my DS to have the service guys fix it.

 

[jerry33]

Just another data point. My 85D was built at the end of May, 2015. 19" base wheels with Primacy tires. Coil springs. The sticker shows 45 PSI. I checked at delivery and they were at 42; I asked my DS to have the service guys fix it.

It's a good idea to only rely on your own high quality pressure gauge and to always check the pressure the morning after anyone has done anything to the car (even if it was non-tire related).

 

[P.Mac]

Just to further complicate things . . . A difference 4 or 5 psi has a significant effect on ride quality. And even a good pressure gauge has a margin of error. I drive an S85 with coils and bought a good gauge ($25) to maintain the recommended 45 psi. Because the ride was much harsher than I remembered from my test drives I stopped in to Big O tires for a consultation. They checked my gauge on the master rig they use to check their gauges each morning and found that my gauge measured 4 psi low. So my 45 psi readings were really 49 psi. Now that I understand my gauge and target a reading of 41 psi to get a true 45 psi my ride is great and my tires seem to be wearing just fine.

 

[jerry33]

bought a good gauge ($25)

No such animal.

 

[Firewired]

The Accutire gauges are only about $20 and are pretty accurate. They show pressure down to 1/10th PSI and I over the years have confirmed their pressures with outher gauges.

 

[Nevek]

No such animal.

Have you experience with these gauges? I have the large one at home and the small one in the car. I've never calibrated them, but at least I know my relative pressure is the same for each wheel.
Amazon.com: Moroso 89570 Tire Pressure Gauge 0-100LB PSI - 2-5/8 Face - Dial Type: Automotive

Amazon.com: Moroso 89562 Pro Series Tire Pressure Gauge, 0-60 PSI: Automotive

I originally thought a digital gauge would be most precise, but any I've had flaked out at one time or another, so I went analogue a few years ago.

 

[jerry33]

I originally thought a digital gauge would be most precise, but any I've had flaked out at one time or another, so I went analogue a few years ago.

A digital gauge is more precise; accuracy is another story (precision means the number of decimal places). In general you pay about twice as much for the same accuracy in a digital gauge.

My experience with low priced gauges has not been good, and no I haven't tried every single one. A higher priced gauge can be calibrated and will last a very long time. You get what you pay for.

 

[AmpedRealtor]

Best gauge ever: Amazon.com: Astro Pneumatic 3018 3-1/2-Inch Digital Tire Inflator with Hose: Automotive