Exceeding Maximum Tire PSI

[jimg.allentown]

Some things to know about tire pressures, load, and vehicle application:

1) Tire pressures are determined by the manufacturer's engineering team for proper handling, load carrying, and tire wear.\
Deviating from the recommended pressures can have detrimental effects.

2) Maximum pressure indicated on the side of the tire is only a MAXIMUM pressure, and is not necessarily right for the vehicle.

3) Overinflating tires leads to premature wear. In general, if the pressure is too high, the center of the tread will wear out first. If pressure is too low, the edges will wear out first.

4) Tire pressures have NO EFFECT on transmission life, stress, or any other factor. Suspension sees to that.

5) Not related to tires directly, overloading your van will have more effect on the engine, transmission, and the van in general than a few psi in the tires. Being nnalert about tire pressures will not save you or your transmission any other part of the van.

 

[Ray,IN]

What nobody seems to have pointed out yet is that the pressure in the tire will increase as you drive, due to the tires warming from friction. 44PSI max sidewall pressure takes that into account. After you've been driving a while, the pressure will be at least 3-4 PSI higher.

There's absolutely no reason to exceed maximum pressure specified on the sidewall. You'd PROBABLY be fine doing it if your tires are in good shape, but it doesn't gain you anything.

Well, Carlisle Tire says you can safely inflate their tires up to 10psi over sidewall stated pressure; IF you also reduce speed by at least 10mph.
You are right however, unless the suspension, axles, springs are also upgraded, nothing changed.

 

[BarnyardEngineering]

i pointed that out yesterday.

Then pump it up to 55PSI. More is better right?

 

[rustred]

Then pump it up to 55PSI. More is better right?

No idea what your talking about.

 

[caterpillar guy]

All in good sense as moderation is needed in all cases.

 

[moresmoke]

Define overloaded! No this was not AI.

 

[timsch]

All of these ratings have a significant safety factor calculated in. You're nowhere near blowing out a tire in good condition running it a few psi over the max pressure rating. I keep all my tires at pressures that will provide even wear. If after a number of miles, you see the center of the tread wearing faster than the outer, lower the psi and learn from it. Some go as far as to mark with chalk across the tread and run down the driveway to check for even wear at different pressures.

Mine are always higher than the recommended pressure in the door jam, and frequently a few psi below max, particularly if its' a FWD where the outsides of the tread tend to wear faster on a tire with lower pressure. If loaded down, I run at max pressure without concern.

 

[Ray,IN]

Define overloaded! No this was not AI.

View attachment 130768

I snapped this picture while refueling at a small truck stop. It is the opposite of overloaded.

 

[caterpillar guy]

If not yours Ray it all depends on how many freezers and such they have added to it. One of the guys I worked for back when would add a chest freezer to his 5th wheel to store more things in and I find most don't even know they are over loaded weight wise with them. Thought does not even cross their minds.

 

[Glenn F.]

I need to make a 325 mile roadtrip with my heavily loaded minivan. Tire sidewall says 44 lbs PSI. Dare I go to 47? I’m just trying to reduce stress on the drivetrain.

Thank you,
Glenn F.

Just an update:

We made it home without issue with all four tires exceeding maximum psi by 3-4 lbs. The load was about 260 sq ft of 3/4” solid white oak hardwood flooring (as well as my wife and myself, traveling luggage, etc.). Rear squat was limited. Weight was equally distributed over the entire 4 x 8 cargo area (rear seats removed).

We were very thankful for a safe trip and have no plans of such loads again.

Thank you,
Glenn F.

 

[Hemmjo]

I routinely run 4 or 5 psi over the tire inflation chart on the door, never have a problem but it does increase mpg a little.

Being over the door spec is a lot different than being over the tire sidewall spec.

I do not recommend going over the sidewalk spec. How did you decide on 3 psi? Not a good idea.

 

[Glenn F.]

Being over the door spec is a lot different than being over the tire sidewall spec.

I do not recommend going over the sidewalk spec. How did you decide on 3 psi? Not a good idea.

I just didn’t want to gamble on any higher. For sure, within reason, over inflating is better than under inflating.

 

[bmaverick]

I need to make a 325 mile roadtrip with my heavily loaded minivan. Tire sidewall says 44 lbs PSI. Dare I go to 47? I’m just trying to reduce stress on the drivetrain.

Thank you,
Glenn F.

Because tire pressure gauges are not calibrated instruments, they are off by ±3psi. The worse ones are the plunger stick types made in China, those are off by ±5psi.

When you state inflation of 47psi, it's still within the 4psi gauge spread of being 44psi overall.

Back in the old days with glass-ply tires and such, you could over inflate by 5psi with tire having odd number of tread ridges, meaning the very center of the tire had tread and not a groove.

All Weather tires today are a 1/2 load rating better than All Season tires. The All Weather tire has a denser compound for traction and can withstand increased over inflation.

If you do over inflate, the rule of thumb is to reduce speed to prevent blowouts. A loaded minivan as you had stated traveling on the interstate may be best in the cooler evenings, less traffic and at speeds of 62mph /100km to safely travel. Hot pavement and high speeds kill tire tread life.

 

[buickanddeere]

Remember the good old days of the Ford Exploders on the freeways ?
Usually in the south in a hot day . On the interstate with the vehicle loaded with luggage and people .
Problem was Ford wanted a smooth ride . Car tires were installed and Ford under inflated the tires for comfort .

 

[ASE guy]

I need to make a 325 mile roadtrip with my heavily loaded minivan. Tire sidewall says 44 lbs PSI. Dare I go to 47? I’m just trying to reduce stress on the drivetrain.

Thank you,
Glenn F.

If the tire isn't too old, I would not worry that much. I would be more concerned about "heavily loaded". Your GVW is also for your transmission.

 

[Blackhole49]

Define overloaded! No this was not AI.

View attachment 130768

I wonder if Jethro was behind the wheel.

 

[buickanddeere]

I wonder if Jethro was behind the wheel.

Care to guess the manufacturer of the Beverly Hillbillies truck .

 

[jimg.allentown]

Care to guess the manufacturer of the Beverly Hillbillies truck .

Oldsmobile

 

[jhwis]

I need to make a 325 mile roadtrip with my heavily loaded minivan. Tire sidewall says 44 lbs PSI. Dare I go to 47? I’m just trying to reduce stress on the drivetrain.

Thank you,
Glenn F.

44 lbs. seems plenty high already

 

[Jhn]

I need to make a 325 mile roadtrip with my heavily loaded minivan. Tire sidewall says 44 lbs PSI. Dare I go to 47? I’m just trying to reduce stress on the drivetrain.

Thank you,
Glenn F.

I don't think it can haul that much weight that more than the recommended psi would be nessessary