Tire over inflation

[loneryder]

Today I had my tires R&B at Costco. When I got the receipt it said the rear tires were inflated to 39#. I like to run 35 so I backed into one of the self service inflation stations. You set the pressure to what you want and it either adds or removes air(nitrogen). The rear tires had 50# and the front had 45. Max inflation on the tires is 50 #. I asked one of the tire guys why they would put 50# in them. He pointed to the door jam label which said 45/48. I've always been told to follow the manufacturers label on the back of the gas door which states 32/32 normal and 41/44 for max load. Running 35/35 is a comfortable ride and I'm getting good tire mileage.
So who out there runs their tires at max pressure? I would have bounced all the way home if I had left it in there.

 

[LongTime_Lurker]

Hypermilers.

 

[spasm3]

My experience has been, its overinflated when its squirrelly in the rain. Generally i go 2-4lbs over placard. More, and it rides hard and slips on wet roads.

 

[walterjay]

I usually go a pound below the recommended pressure since I drive without any weight.

 

[eljefino]

Wait, your door jam and gas door disagree? What's going on here?

 

[Rmay635703]

Wait, your door jam and gas door disagree? What's going on here?

Sounds like a truck/suv

Under 40psi on new vehicles seems to get me more undulations and blowouts so I keep them aired

 

[loneryder]

Sounds like a truck/suv

Under 40psi on new vehicles seems to get me more undulations and blowouts so I keep them aired

Mercedes ML suv.

Wait, your door jam and gas door disagree? What's going on here?

So what is everyone using, the door jam or the gas door specs? I know some cars don't have any specs on their gas door.

 

[JWC86]

The recommended specs for my truck with the factory tires is 60F/80R. With factory tires I used to run around 50psi.

With 37x12.5-17 tires I only run 35F/30R. They still have more load rating at that pressure than I will need(and more that the truck is rated for). Most guys get bent out of shape about those pressure in a 1 ton truck but it rides great and the tires weR perfect. I also chalk tested them a few times and they are perfect.

 

[BigCahuna]

Unless the pressure on the door is for the same brand and tire on the vehicle, I set the pressure to whats on the tire. Never had any issue doing it that way. I also only use a digital pressure gauge. Old style gauges, are as good as guessing how much air is in the tire.,,,

 

[JWC86]

Old style gauges, are as good as guessing how much air is in the tire.,,,

That really depends on the gauge. Lots of analog gauges out there that are more accurate than lots of digital gauges. (I worked at a place that calibrated gauges once)

 

[mdocod]

It's not uncommon for there to be a wide range of pressures recommended by the manufacture for different conditions, loads, speeds, and tire size options. In the USA, it's more common for them to standardize on a single "one size fits all" or sometimes "2 sizes fit all" door placard spec, however, find the manual for the same car published in Europe, and there's often a table of pressures, sometimes with different pressures for each axle, for different conditions and loads. My S60 has pressures from 32-44PSI recommended depending many factors. You ML probably does have valid tire pressure options from ~32-48PSI.

 

[mdocod]

Unless the pressure on the door is for the same brand and tire on the vehicle, I set the pressure to whats on the tire. Never had any issue doing it that way. I also only use a digital pressure gauge. Old style gauges, are as good as guessing how much air is in the tire.,,,

I hope you're trolling us...

 

[BigCahuna]

That really depends on the gauge. Lots of analog gauges out there that are more accurate than lots of digital gauges. (I worked at a place that calibrated gauges once)

In the last 20 years, I haven't found any 2 analog gauges that will give the same reading. That's why I use the digital type.,,

 

[JWC86]

In the last 20 years, I haven't found any 2 analog gauges that will give the same reading. That's why I use the digital type.,,

Which analog gauges have you tried?

 

[BigCahuna]

I hope you're trolling us...

Why would you adjust your tire pressure for a tire that may not be manufactured anymore?. You can run a tire pressure as low as you want depending on how your using the tire. I'm not talking off road or high performance use. But for normal street use, You will never go wrong setting it to what the new tire is rated for...

 

[thescreensavers]

That's a first for me, never knew about gas door tire specs.

 

[MParr]

I don’t know if either of my vehicles has a tire pressure decal on the back side of the gas door. I haven’t even payed attention to it. I go by the decal on the door pillar.

 

[Astro14]

Why would you adjust your tire pressure for a tire that may not be manufactured anymore?. You can run a tire pressure as low as you want depending on how your using the tire. I'm not talking off road or high performance use. But for normal street use, You will never go wrong setting it to what the new tire is rated for...

You and tacticaldriver would get along - hey, if 35 is OK, then 50 is good, and 65 must be better!

Fill to vehicle spec or tire spec?

Do you guys fill up your tires to the PSI recommended by the car manufacturer or do you base it on the max tire pressure of the tire and adjust accordingly? For instance, my Charger doesn't show a recommended PSI anywhere, and I mean ANYWHERE on the vehicle/manual. Online I've seen a lot of...

bobistheoilguy.com

Not one vehicle manufacturer suggests using sidewall pressure - that is a maximum limit for the tire, not a recommended pressure.

Start here: http://barrystiretech.com/inflationpressure.html

 

[CapriRacer]

Unless the pressure on the door is for the same brand and tire on the vehicle, I set the pressure to whats on the tire. Never had any issue doing it that way. I also only use a digital pressure gauge. Old style gauges, are as good as guessing how much air is in the tire.,,,

BigCahuna,

We've had this conversation before.

What's on the sidewall of the tire are maximums. Even says so!! Those are not recommendations or even suggestions.

And the doorsticker? It's required by the government. It has a size, but doesn't have the tire brand - and that's because it doesn't matter who makes the tire, but the size does matter!

 

[CapriRacer]

Today I had my tires R&B at Costco. When I got the receipt it said the rear tires were inflated to 39#. I like to run 35 so I backed into one of the self service inflation stations. You set the pressure to what you want and it either adds or removes air(nitrogen). The rear tires had 50# and the front had 45. Max inflation on the tires is 50 #. I asked one of the tire guys why they would put 50# in them. He pointed to the door jam label which said 45/48. I've always been told to follow the manufacturers label on the back of the gas door which states 32/32 normal and 41/44 for max load. Running 35/35 is a comfortable ride and I'm getting good tire mileage.
So who out there runs their tires at max pressure? I would have bounced all the way home if I had left it in there.

Wait, your door jam and gas door disagree? What's going on here?

I'm with eljefino - that doesn't make sense.

Perhaps the fuel filler door has a couple of options depending on various conditions - one of which will match the door sticker! Use the door sticker!