Tire Pressure; per Honda

[rusted]

So I've looked at a few CRX's including my own, and none have a tire pressure spec on the door jamb. Nor is it in the glove box.

I've checked 2 service manuals as well; silence.

What inflation pressure do you run, and where did you get that value?

[I know the MAX pressure shown on the sidewall is just that; not the car-dependent specification.....]

[FrodoGT]

Uhh..on the tire..

[CRXperiment]

I run like 28-30 on each tire, thats what it says in my glove box (91 si). Keep the spare inflated to like 60 psi.

[ironman85]

Originally Posted by rusted

the car-dependent specification.....]

wha? car specific? thought it was tire specific..........casue if i am on 70% sidewall...and your on low profiles, you will need a higher pressure then me.....

[FrodoGT]

Yeah man, your car doesn't care what tire pressure your running..the tire does. The tire has a weight rating and a pressure that it is meant to hold for a given weight and tire spec..etc etc..the pressure on the side isn't really the max, its the recommended tire pressure.

[Killa_CRX]

tire pressure is almost entirely about personal preference...

Although, as you go lower than 30psi, you're likely to develope a tire vibration problem (I see this at work all the time).... also the lower the pressure the more flexable the tire... also the lower profile tire you run the higher pressure you should keep your tires (seriously prevents bending and screwing up wheels from pot holes, to an extent).... I keep my tires at 35psi right now, with stock sized 'performance' tires.... when I had my low profile tires (40 series) I kept the pressures closer to 37-40psi.

30psi or there abouts is highly recommended.... anything above that is purely personal ride feel preference.

[rusted]

Originally Posted by ironman85

wha? car specific? thought it was tire specific..........casue if i am on 70% sidewall...and your on low profiles, you will need a higher pressure then me.....

The tire spec is the maximum safe pressure; but that may be way too hard for a given car. For example, remember the Ford Explorer rollover fuss several years ago? Ford wanted the pressures lower, for a soft ride, but the tire mfgr wanted higher. At the lower pressures, the tires failed more often.

The correct answer takes into account both the tire size and the vehicle involved.

[ironman85]

Originally Posted by rusted

Ford wanted the pressures lower, for a soft ride, but the tire mfgr wanted higher. At the lower pressures, the tires failed more often.

yea, so when they DIDN"T go with firestones recomended pressure....they failed.

go with whats on the tire lol

[Killa_CRX]

Originally Posted by ironman85

yea, so when they DIDN"T go with firestones recomended pressure....they failed.

go with whats on the tire lol

Actually, both companies have been found at fault, so far. Firestone for defective tires, that on a long enough time line would have failed anyways. And Ford for a lower than specified pressure (26 instead of 35) which accellerated tire failure (lower pressure, more flexable the tire, the more the tire flexes the more heat is created, the excessive heat caused the tread sepperate fairly quickly).

That was just plain stupid of Ford though... for a vehicle that heavy, I'd never run that low of tire pressure... that's just asking for trouble. But they weren't the only ones at fault, because the goodyear tires that were used, with the same pressure settings and recomendations, hardly ever failed.

[rusted]

Originally Posted by Killa_CRX

That was just plain stupid of Ford though... for a vehicle that heavy, I'd never run that low of tire pressure... that's just asking for trouble. But they weren't the only ones at fault, because the goodyear tires that were used, with the same pressure settings and recomendations, hardly ever failed.

BUT more tire pressure both made the ride harder, AND made the vehicle more squirrelly/less stable, and raised the CG. Big issues: Ford built Exploders on Ranger truck frame, cheaper but higher CG and [and this appears to be underaddressed..] flipping should not be fatal.

There's a NOVA episode that shows the Mercedes convertible on the Autobahn; it flips at ~200Kph and slides upside down for ~1km and flips upright again. The driver opens the door and gets out....

But we've drifted off my OT, which was what Honda spec'ed...

[turtlecrxsi]

I think pressure is tire dependent depending on the wheel size and specific application. With my 14" wheels I used 185/60-14 tires... when new 38psi, when started putting miles on them I kept them at 36psi, when I wanted to ride on tarmac and dirt I kept them around 34-36psi, when I wanted to launch hard with minimial wheel spin and slip the clutch I rode at 32psi. By the time the tires were rotated 4 times with the various driving I've done the tires were pretty well done for. I only had an inch drop so camber wasn't all that bad. Basically, I've found out that the lower the pressure the better the traction for launching, the higher the pressure the more wheel spin from a standing start. Somewhere in the middle gave the best of both worlds.