Recommended Tire Pressure

[wasnt]

Since I bought my car, my tire pressure was always around 40 PSI. My tires say "maximum under load of 51 PSI". What would be the recommended tire pressure? My tires are the Hankooks that came with the car (3.8 RWD).

EDIT: I didn't post this in the "Wheels, Tires, Brakes and Suspension Performance Modifications" forum because this isn't a performance modification AND... that forum doesn't get nearly the same visitors as this one.

 

[quanva]

i personally try to keep my pressures around 40 cold

 

[2011 Genesis 4.6]

check the sticker on the drivers door frame, it will give you a manufactures tire pressure, its usually 32psi front 29-32 psi rear, engine weight on the front so its higher, however those pressures are so the tires sidewall can flex and help the suspension absorb road bumps, I personally run 40 psi for better resistance to tire flex.

 

[ksoze]

The driver side door hinge contains the manufacturers recommendations, as with all cars. Anything outside of this is your decision, but the tire and car maker posted those numbers for a reason.

 

[TroyK]

Since I bought my car, my tire pressure was always around 40 PSI. My tires say "maximum under load of 51 PSI". What would be the recommended tire pressure? My tires are the Hankooks that came with the car (3.8 RWD).

EDIT: I didn't post this in the "Wheels, Tires, Brakes and Suspension Performance Modifications" forum because this isn't a performance modification AND... that forum doesn't get nearly the same visitors as this one.

the door jamb placard on my car (htrac v6) says 33 psi cold. if you've been driving around with 40 psi in the tires...you might notice a ride improvement if you take some air out of those tires!

 

[srobak]

The driver side door hinge contains the manufacturers recommendations, as with all cars. Anything outside of this is your decision, but the tire and car maker posted those numbers for a reason.

It is important to note that this is only reflective for OEM tires. Obviously if you change tire types, rims, etc this could change. For example - running only 33 lbs in some super-low pro performance tires is only going to result in some really poor handling and some pretty messed up rims as they typically run 45-60lbs.

 

[Mark_888]

It is important to note that this is only reflective for OEM tires. Obviously if you change tire types, rims, etc this could change. For example - running only 33 lbs in some super-low pro performance tires is only going to result in some really poor handling and some pretty messed up rims as they typically run 45-60lbs.

The recommended PSI is not just for OEM tires, but for all tires, assuming that they meet specifications (size, aspect ratio, etc) and are a similar type of tire.

40 PSI (cold tire pressure measured at 70 F after not driving the car for about 4 hours) is way more than is needed and is going to result in a stiffer ride. For some owners, 33 PSI is a little too low, so 35 PSI would be fine, but I think 40 PSI is just too high for most unless they are street racing.

 

[xsolara]

At highway speed in the Summertime that 40lbs could exceed 51lb rating...your just asking for a blowout under pothole conditions

 

[2011 Genesis 4.6]

At highway speed in the Summertime that 40lbs could exceed 51lb rating...your just asking for a blowout under pothole conditions

NO

That rating on the tire also says COLD, they know while driving the tire heats up and that pressure rises

 

[ksoze]

NO

That rating on the tire also says COLD, they know while driving the tire heats up and that pressure rises

If it is at the recommended COLD temperate. 40 is not. That was the point.

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[PMCErnie]

Funny, there is always that one percent, or maybe a little more , that never gets the info. Every car I've ever driven has the manufacturer's recommended inflation pressure shown either on the driver's door jamb, or in the glove box.
The location of this info is also mentioned in the manual. If you overinflate, expect the center portion of your tires to wear out first.

 

[wasnt]

Funny, there is always that one percent, or maybe a little more , that never gets the info. Every car I've ever driven has the manufacturer's recommended inflation pressure shown either on the driver's door jamb, or in the glove box.
The location of this info is also mentioned in the manual. If you overinflate, expect the center portion of your tires to wear out first.

And yet this thread is full of debate, hence my questioning. I know what it says in the manual, on the tire, in the door jam. I am asking what other do.

In hindsight, my wording could've been better in my OP.

 

[kn5owa]

And yet this thread is full of debate, hence my questioning. I know what it says in the manual, on the tire, in the door jam. I am asking what other do.

What this "other" does is to follow the recommended pressure + 1 lb for expected leakage.

The recommended pressures for my Genesis (33/35 lbs) are already way higher than what used to be recommended (a few years back, to be sure).

 

[amartz]

I personally run 40 psi for better resistance to tire flex.

Unless you are going motocrossing in a parking lot every day (which *may* describe Jax rush hour! ;-) ), that is overboard, and would tend to wear the middle of the tire faster.

 

[Mark_888]

What this "other" does is to follow the recommended pressure + 1 lb for expected leakage.

The recommended pressures for my Genesis (33/35 lbs) are already way higher than what used to be recommended (a few years back, to be sure).

The recommended tire pressure depends on the weight of the car, and the chassis dynamics, which is why it might be higher than some older cars you drove. That is the case with my previous car, which was 500 lbs lighter.

 

[Mark_888]

And yet this thread is full of debate, hence my questioning. I know what it says in the manual, on the tire, in the door jam. I am asking what other do.

In hindsight, my wording could've been better in my OP.

So how do you determine who is correct if some say to use the recommended 33 PSI and others use 40 PSI?

I would not pay any attention to what the tire says, as that is the maximum. If an elevator says the maximum passenger load is 2500 lbs, do you really want to be on the elevator when it has a load of 2500 lbs?

 

[ksoze]

The door jamb lists the recommended COLD tire pressure. That's the last word. There are no counter opinions, debates, field experiences, friend who said he had an uncle who knows a guy, that will change that fact.

If you find the ride better with over or under inflated tires, go for it. But the tire will not perform or last as designed if you deviate from those printed recommendations, which one can assume were not just picked out of thin (or overinflated) air.

 

[2011 Genesis 4.6]

Over inflated tires will show by wearing out he center quickly, I have never had that happen

I drive aggressively, 99% of the time. I enjoy driving.

 

[Monolith2001]

I run 38 cold all the way around and have been very happy with the ride and economy. My Hankooks were wearing great at that psi (23,000 miles)...only an alignment problem sort of forced me to get the tire recall done earlier than planned. If in doubt, run what the manual/door jam says but ideal tire pressure is not a hard number but a range that is defined by a large number of factors that will vary over a range. For safety, stay at or above the cold limits (tire or car manufacturer...whichever is higher) and stay at least 10 psi below the max rating and you "should" be in the safe operation zone unless you are doing some really extreme stuff.

 

[wasnt]

So how do you determine who is correct if some say to use the recommended 33 PSI and others use 40 PSI?

I would not pay any attention to what the tire says, as that is the maximum. If an elevator says the maximum passenger load is 2500 lbs, do you really want to be on the elevator when it has a load of 2500 lbs?

You're assuming I knew everyone's answer before I asked my question. I didn't assume that people would vary so wildly. This is a forum for discussion so I figured this is a good question to ask, surprisingly a few people get wacked out when asking a question like this.

Also, my stating what the tire said was just informational so the more lazily inclined people didn't have to go look at their tire... plus I was just looking at the tire so I knew that number.