How much to inflate tires?

[parky76]

I have a 99 Civic. I was told by a repair guy at my work, that since the recommended tire pressure for my tires was 30 psi..and the maximum pressure for the tires was 45 psi...i should inflate them to 35 psi.

he said that will increase life, handling, better gas mileage, braking, etc.

what y'all think?

[paximperium]

He's overstating it. The 30psi for the tire was developed by the car company based on the weight of the vehicle for a balance of traction, longevity and ride comfort. Some car manufacturers even change the recommended psi based on the load the vehicle will take(one passenger vs 5 and cargo etc.)

In general over inflating your tires a bit will decrease rolling resistance and should give a mildly increase gas mileage. You will suffer ride comfort and will feel more bumps. You will lose a bit but not really a relevant amount of traction. I've heard both sides of the argument concerning tire longevity and doubt it will really change it too much.

[wackyvorlon]

Bear in mind, the calibration on most tire gauges is very poor. 5 psi isn't going to make a large difference, and depending on the situation the pressure gauge could easily be that many psi out. I would stay at 30 to 35.

[madurobob]

Depends on the tires, too. Some tires are more susceptible to deformation from over or under inflation. Sidewall strength, tread thickness, etc... makes a difference.

FWIW, the Dunlop tires I ran on my 97 civic seemed to run better at 35psi than at 30. 30 PSI felt a little "marshmallow-ey". And they were a pretty low profile tire.

[SimonD]

Read your car manual. Seriously.

[COLONEL]

I always found 32psi was good for a car .

[parky76]

yeah. my cheap 5$ tire gauge sux. i think ill put them to 35 and see how it feels.

[paximperium]

yeah. my cheap 5$ tire gauge sux. i think ill put them to 35 and see how it feels.
Get a better tire gauge. I got a decent electronic one for about 15bucks at costcos and it works very well.

[Bob Blaylock]

Trade your Honduh in for a Hyster E60; then you won't have to worry about tire pressure.

[Zep]

I have a 99 Civic. I was told by a repair guy at my work, that since the recommended tire pressure for my tires was 30 psi..and the maximum pressure for the tires was 45 psi...i should inflate them to 35 psi.

he said that will increase life, handling, better gas mileage, braking, etc.

what y'all think?I have the exact same car and year model. I run my tyres at 32psi front, and 28psi back because it is a front-wheel drive with the engine weight up front. It's a few psi above the manufacturer's spec, but I do long-distance driving with weight on board and it helps.

Tyres can run OK in a certain range. So for 30psi specified, for example, they are actually OK in the range from about 28 to 32psi. You can be picky and check every day to keep 30psi exactly if you like. Although as said, garage tyre gauges are rarely calibrated. So you can rarely rely on them to be super accurate.

The real trick to tyre inflation is to make sure they are the same pressure on each side of the car all the time - not unbalanced side to side. So you can usually use the same garage type pump and get each side exactly the same pressure, even though the gauge may be a pound or two off.

Re the Civic, I found that over-inflating causes excess wear on one part of the tyre due to uneven tyre contact with the ground (the tyre tread bulges, and only the bulge makes contact) which wears tyres out faster.:( For the same reason, it's also reduces available road contact for braking and steering.:eek: Plus it makes for a heck of a bumpy ride in a small, light car.:bigtank:

[Smackety]

I have a 99 Civic. I was told by a repair guy at my work, that since the recommended tire pressure for my tires was 30 psi..and the maximum pressure for the tires was 45 psi...i should inflate them to 35 psi.

he said that will increase life, handling, better gas mileage, braking, etc.

what y'all think?

as long as the rims are off the ground, you are good to go. Anyone who has ever used fix-a-flat knows what I mean.

[Lanzy]

Well then, 45 should be even better.:D

[COLONEL]

as long as the rims are off the ground, you are good to go. Anyone who has ever used fix-a-flat knows what I mean.Fix a flat ? I have a friend that runs a tire store and hates the stuff . Its good for the person that get the flat but for the guy that chages the tire later it is a awful mess to deal with.

[N.Texas]

"Under normal loads, inflate tires according to the vehicle manufacturer's recommendations, NOT the maximum pressure listed on the sidewall. In any case, one should never exceed this maximum pressure"

"Tires must be checked when they are cold; that is, before they have been run a mile. If you must drive over one mile for air, before you leave home, measure the cold inflation pressure of each tire and record the actual under-inflation amount for each tire.

"Upon arriving at the service station, measure each tire's inflation again and then inflate the warm tire to a level that is equal to this warm pressure, plus the cold under-inflation amount."

"Use an accurate tire pressure gauge to determine your tire pressure. You can't tell when tires are 'low,' or under-inflated, just by looking. Air meters at service stations may be inaccurate due to exposure or abuse. You should have your own personal tire gauge to be sure."

http://www.drivers.com/article/354/

[madurobob]

Fix a flat ? I have a friend that runs a tire store and hates the stuff . Its good for the person that get the flat but for the guy that chages the tire later it is a awful mess to deal with.

Much better now than it used to be. It used to be highly flammable and a spark created when removing the tire could set it off. People complain about an over litigious society and tort reform, but it was only after several deaths and big lawsuits that the makers reformulated to make it safe.

At any rate, if you use fix-a-flat tell your tire guy before he removes the tire. Even if its no longer highly flammable its still a yucky mess and he'll appreciate being prepared.